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Carbon fibre-reinforced ultra-high temperature ceramics (UHTCs) are considered a class of promising materials for several applications, the most appealing ones being in the aerospace sector. Reinforcement is necessary to overcome the brittleness and low thermal shock resistance of ceramics and is often provided through the addition of carbon fibres or other carbon-based phases, such as nanotubes, graphene, and graphite. The present work is focused on the toughening of UHTCs through incorporation of 30−50 vol% thin, ordered graphite layers from conventional filter paper followed by hot pressing sintering. Cellulose filter paper was selected because it undergoes thermolysis with no melting stage forming a strong carbonaceous residue that can be used as toughener. Microstructure and mechanical properties of toughened composites were compared to those of other materials reinforced with short carbon fibres and the effect of different distribution of graphite was studied. Addition of graphite allowed toughness to be increased from 3−4 MPa·m1/2 (for un-reinforced materials) to 5.1−5.5 MPa·m1/2, similar to results obtained with short fibre reinforcement. The high-temperature properties, such as strength and toughness as well as oxidation resistance at 1500 ℃, were also examined.

At present, the friendly recycling of paper industry effluent sludge has gained great prominence due to the ecological and economic benefits. The aim of this work is to evaluate the influence of the incorporation of paper industry effluent sludge into a red wall tile formulation (BIII group), replacing natural limestone material by up to 10 wt.%. For this purpose, five red wall tile formulations were developed by the dry process, pressed at 47 MPa, and fired at 1170 ºC by using a fast-firing cycle. The wall tile formulations were characterized in terms of chemical analysis, thermal analysis (DTA-TG), and dilatometric analysis. The influence of paper industry effluent sludge on the technical properties (apparent density, water absorption, and flexural strength) and sintered microstructure was investigated. The results showed that red wall tiles containing up to 10 wt.% of paper industry effluent sludge have very good usable final properties, indicating their suitability for the wall tile industrial production (BIII group - ABNT NBR ISO 13006). Such results emphasize the feasibility of ecological and economic recycling of paper industry effluent sludge for the production of red wall tiles.

The microstructure of fibrous paper plays an important role in its property investigation. In this study, an approach is proposed to extrapolate a 2D image into a virtual 3D microstructure. Five types of handsheets made of different pulps were prepared. Then, a hybrid function of two-point correlation and lineal-path function (S2&L2) and co-occurrence correlation functions (CCFs) was used in the simulated annealing reconstruction method. Thus, microstructures of two-phase fiber-pore handsheets were reconstructed using 2D scanning electron microscopy images. Finally, penetration simulations and calculations of the absolute permeability of handsheets were conducted. The statistical values of two-point correlation function (S2) and lineal-path function (L2) extracted from the reconstructed images were used to characterize the reconstruction accuracy, and the comparisons of reconstruction accuracy and time were made. The study results showed that the 3D microstructures of fibrous handsheets could be reconstructed effectively by S2&L2 and CCFs, identifying with the targets. The accuracies were around 10−5, and the reconstruction times by CCFs were shortened by 30–60% compared with S2&L2. Moreover, the visual permeability simulation results could reflect the structural difference of handsheets, according to the calculated absolute permeability. These findings provide a guidance for 3D reconstruction of natural fiber paper.

Expansive soil exhibits significant swellings and shrinkages, which may result in severe damage or the collapse of structures built upon it. Calcium-based admixtures, such as lime, are commonly used to improve this problematic soil. However, traditional chemical additions can increase significant environmental stress. This paper proposes a sustainable solution, namely, the use of lignin fiber (LF) from the paper industry to partially replace lime as an amendment for expansive soils. Both the macroscopic and microscopic characteristics of the lignin fiber-treated expansive soil are extensively studied. The results show that the mechanical properties of expansive soil are improved by using lignin fiber alone. Under the condition of an optimal dosage of 8%, the compressive strength of lignin fiber-modified soil can reach 193 kPa, the shear strength is increased by 40% compared with the untreated soil, and the water conductivity is also improved with the increase in dosage. In addition, compared with 2% lime-modified soil, the compressive strength of 8% lignin fiber- and 2% lime composite-treated expansive soil increased by 50%, the cohesion increased by 12%, and the water conductivity decreased significantly. The microstructure analysis shows that at an 8% lignin fiber content, lignin fibers interweave into a network in the soil, which effectively enhances the strength and stability of the improved soil. Simultaneously, the fibers can form bridges across the adjacent micropores, leading to the merging of pores and transforming fine, dispersed micropores into larger, connected macropores. Lime promotes the flocculation of soil particles, forming larger aggregates and thus resulting in larger pores. The addition of fibers exerts an inhibitory effect on the flocculation reaction in the composite-improved soil. In conclusion, lignin fibers are an effective addition used to partially replace calcium admixture for the treatment of expansive soil, which provides a sustainable and environmentally friendly treatment scheme for reducing industrial waste.

Collect screen paperboard of mine power transformer and ordinary power transformer in practical lifetime cycle to make insulation test samples, and according to the standard of power, use test means such as viscosity tester, scanning electron microscopy to compare and analyze microstructures of insulation paper such as polymerization degree, surface morphology of mine power transformer and ordinary power transformer, as well as electrical properties such as partial discharge and electrical strength; at the same time, effect of microstructure changes on electrical performances during aging was discussed. The analysis results show that the insulation defects gradually form and expand in the insulation paper during the aging process; compared with the insulation paper of ordinary power transformers, the surface morphology changes of the insulation paper of mine power transformers are more obvious, and the formed defects are more significant.In the aging process, the polymerization degree of insulation paper of ordinary power transformer and mine power transformer presents a gradual decline trend, but the decline speed of polymerization degree of mine power transformer insulation paper is faster.The operating environment of mining area is the main reason that the aging of insulation paper of mine power transformer is more serious than that of ordinary power transformer.In the process of operation, the insulation paper of mine power transformer will produce more discharge quantity, more discharge times and wider discharge phase than ordinary power transformer.In the aging process, the electrical strength of insulation paper of both ordinary power transformer and mine power transformer decreases gradually, but the electrical strength of insulation paper of mine power transformer is lower than that of ordinary power transformer.The microstructural defects of insulation paper of mine power transformers are the direct causes of the more significant changes in their electrical properties.In the process of state monitoring and maintenance of power equipment, it is suggested that the insulation state monitoring of mine power transformers should be carried out strictly according to the power standards,electrical property parameters are more suitable for insulation status monitoring and fault diagnosis of mine power transformer.

As two important industrial manufacturing materials, ceramics and metals have their own advantages and disadvantages in terms of physical, chemical, and mechanical properties. The field of material manufacturing has witnessed efforts to develop technical processes that can properly combine these two alloys, aiming to effectively use their respective advantages. The welding technology for ceramics and metals, as a research topic with broad prospects, is comprehensively and deeply analyzed in this review. The current research progress in this field is analyzed from different process perspectives such as fusion welding, brazing welding, diffusion welding. By using appropriate intermediate materials between these two materials, the residual stress and brittle intermetallics near the interface of the transition joint can be minimised by solving the thermal expansion mismatch, reducing the bonding temperature and pressure.

Ceramic matrix composites (CMCs) based on silicon carbide (SiC) are promising materials for applications as structural components used under high irradiation flux and high temperature conditions. The addition of SiC fibers (SiCf) may improve both the physical and mechanical properties of CMCs and lead to an increase in their tolerance to failure. This work describes the fabrication and characterization of novel preceramic paper-derived SiCf/SiCp composites fabricated by spark plasma sintering (SPS). The sintering temperature and pressure were 2100 °C and 20−60 MPa, respectively. The content of fibers in the composites was approx. 10 wt.%. The matrix densification and fiber distribution were examined by X-ray computed tomography and scanning electron microscopy. Short processing time avoided the destruction of SiC fibers during SPS. The flexural strength of the fabricated SiCf/SiCp composites at room temperature varies between 300 and 430 MPa depending on the processing parameters and microstructure of the fabricated composites. A quasi-ductile fracture behavior of the fabricated composites was observed.

The paper production is developed throughout the world, therefore, more paper sludge waste (PSw) is accumulating. The aim of this work was to determine the properties of PSw burned at 900 °C and its impact on physical−mechanical properties of cementitious matrix and evaluate its usage/utilization possibilities in cementitious materials. For the implementation of the aim, cement-based specimens were prepared and their −mechanical properties were determined. Specimens from five compositions were formed, with 2.5%, 5%, 7.5%, and 10% of the cement by weight replaced with PSw. When 5% of the cement was replaced with PSw, the compressive strength increased by approximately 7%, although density and ultrasound velocity slightly decreased (up to 1.5%). When 7.5% PSw was added, the compressive strength of the specimens decreased. To summarize, it can be stated that up to 5% PSw may be utilized/used for the preparation of cementitious mixtures. The usage of the waste allows environment conservation, reduced amount of cement in mixtures, and improvement of properties of cementitious materials.

Soil-water characteristic curve (SWCC) plays an important role in defining the hydro-mechanical behavior of unsaturated soils. Biochar has the properties of porous structure, high specific surface area and high adsorption. The hydraulic characteristics of biochar-amended soil may change due to the influence of natural environmental factors when applied as the cover layer of landfills. In order to study the effect of biochar content on the water retention behavior of biochar-clay mixture in full suction range, the suction of samples was controlled by vapor equilibrium technique (suction range 3–368 MPa), filter paper method (suction range 0–40 MPa) and pressure plate method (suction range 0–1.5 MPa), and the water content and saturation degree of samples after suction equilibrium were determined. The soil-water characteristic curve of biochar-clay mixtures was obtained in the full suction range. The results showed that: (1) The soil-water characteristic curve in the full suction range of biochar-clay mixtures was effectively expressed by the three suction testing methods. (2) Biochar can affect the water retention behavior of clay, but within a certain range of suction, the water retention behavior of biochar-clay mixtures was also related to the pore structure and the morphology of water in the pores. (3) As measured by the pressure plate method, the air intake value of samples decreased as the biochar content increased. When the suction value was less than the air intake value, a horizontal section appeared in the curve, and the samples were always in the saturated state. The greater the content of biochar, the better the water retention of the sample. (4) The relationship between the water retention capacity of biochar-amended clay and biochar content was explained by the microscopic structure of the biochar-clay mixture and the distribution form of biochar in clay.

New compounds, called inhibitors, provide anti-yellowing effect for mechanical pulps and papers, when added to the coating formulation. The rheology of coating mixtures, which contain clay, ground calcium carbonate, starch, latex, inhibitors and other minor additives, affects to a certain extent the final quality of the coated paper. The purpose of this work is to investigate the effect of the total weight charge of inhibitors, when present between coating color ingredients, on the thixotropy and visco-elasticity of the mixture and other rheological properties. We also study the degree of interaction between inhibitor and coating ingredients using Transmission Electron Microscope (TEM) and water retention measurements.

The stability of microstructure at high temperatures is necessary for many applications. This paper presents investigations on the effect of changes in temperature on the microstructures of additively manufactured Ti6Al4V(ELI) alloy, as a prelude to high temperature fatigue testing of the material. In the present study, a Direct Metal Laser Sintering (DMLS) EOSINT M290 was used to additively manufacture test samples. Produced samples were stress relieved and half of these were then annealed at high temperatures. The samples were then heated from room temperature to various temperatures, held there for three hours and thereafter, cooled slowly in the air to room temperature. During tensile testing, the specimens was heated up to the intended test temperature and held there for 30 minutes, and then tensile loads applied to the specimens till fracture. Metallographic samples were then prepared for examination of their microstructures both at the fracture surfaces and away from them. The obtained results showed that changes in temperature do have effects on the microstructure and mechanical properties of Ti6Al4V(ELI) alloy. It is concluded in the paper that changes in temperature will affect the fatigue properties of the alloy.

To address the challenges of low roof-contacted filling rates and poor roof-contacted filling effects in an iron mine stope in the Anhui province, a composite expansive agent is introduced into the last roof-contacted filling slurry. This approach allows for active roof-contacted filling and reduces filling costs simultaneously. This paper analyzes the physical and chemical properties of the test materials to assess the strength evolution law and determine the optimal ratio for expansive backfill. Herein, a response surface methodology (RSM) is employed for performing the strength ratio test of expansive backfill using Box−Behnken design (BBD) in Design-Expert software. Further, the influence rules of slurry mass fraction, cementitious powder mass fraction, and composite expansive agent mass fraction on the compressive strength of expansive backfill are studied. Subsequently, the paper establishes response surface regression models for analyzing the compressive strength of expansive backfill. The results show that the regression coefficients for 3 d, 7 d, and 28 d compressive strength regression equations are 0.9813, 0.9758, and 0.9857, respectively. These figures suggest that the regression models have a high degree of fitting. Further analysis of variance and comparison between measured and predicted values suggest the accuracy and reliability of these models. The results reveal that the compressive strength of expansive backfill is considerably affected not only by a single factor but also by the interaction between various factors. Among the single factors, cementitious powder mass fraction exerts the greatest influence, followed by composite expansive agent mass fraction, while slurry mass fraction has the least effect. The interaction between slurry mass fraction and cementitious powder mass fraction considerably affects the compressive strength during the early and middle stages. Meanwhile, the interaction between the cementitious powder mass fraction and composite expansive agent mass fraction substantially affects the later compressive strength. Based on these findings, this paper applies the goal programming method to optimize the ratio of expansive backfill, and the optimization models are established considering the compressive strength, expansion effect, and filling cost of backfill. The optimal ratio of expansive backfill is determined to be 69% slurry mass fraction, 10% cementitious powder mass fraction, and 3×10–4 composite expansive agent mass fraction, meeting the requirements of compressive strength and roof-contacted filling. Finally, the microstructure of expansive backfill is analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results reveal that the composite expansive agent allows the filling slurry to expand and deform during the plastic stage, thereby improving the roof-contacted filling rate. Meanwhile, the composite expansive agent can loosen the internal structure and increase porosity, thereby reducing the compressive strength of backfill.

Superalloys play a critical role in aerospace applications due to their exceptional mechanical properties at high temperatures. The application of magnetic fields to regulate superalloys presents novel avenues for optimizing microstructures, controlling solidification defects, and enhancing their high-temperature properties. This paper provides a comprehensive review of research findings on the influence of magnetic fields on the microstructure and properties of superalloys. It systematically elucidates the effects of different types and intensities of magnetic fields on alloy solidification. Moreover, this paper extensively explores the effects of various types of magnetic fields on the phase composition, microstructure, and properties of superalloys, including Ni-based and Co-based alloys, as well as high-entropy alloys. The underlying mechanisms behind the impact of magnetic fields on these alloy types are thoroughly analyzed. Finally, the last section offers a brief summary of the current development status and prospects of magnetic field-regulated superalloys.

In this paper, the microstructure and mechanical properties of CoCrFeNiMox (x = 0, 0.1, 0.3, 0.5, 0.7, and 1.0) high-entropy alloys (HEAs) prepared with high-vacuum arc melting method were studied in detail. After Mo-doping, the strengthening mechanism of HEAs mainly included the component segregation strengthening and the second phase strengthening. Cr and Mo elements were enriched at the grain boundary of HEAs, which leaded to the formation of σ phase and strengthens the alloys. The microhardness and strength increased with Mo contents, while the elongation decreased gradually. Among which, the higher microhardness, yield strength, and ultimate tensile strength of CoCrFeNiMo0.3 alloy reach 205.96 HV, 292.22 MPa, and 593.25 MPa, respectively, in compared with other alloys. More importantly, the percentage elongation of which remains 37.36%, and the microhardness distribution was uniform with an average value of 7.4 GPa and an elastic modulus of 263.6 GPa. The research findings presented in this paper could serve as a valuable theoretical basis and practical foundations for the strengthening efforts of face centered cubic (FCC) HEAs.

NiTiTa ternary shape memory alloy is a potential biomedical material, and wire arc additive manufacturing (WAAM) technology has been widely used in the research of NiTi alloys. It is of great significance to study the effect of Ta addition on the microstructure and properties of WAAM NiTi alloys. In this paper, 5-layer NiTi and NiTiTa alloy walls were fabricated by WAAM technology, and the effects of Ta addition on the microstructure, phase transformation behavior, mechanical properties and corrosion resistance of NiTi alloys were systematically studied. The results show that the grains of the NiTiTa alloy are remarkably refined compared with NiTi alloys, and the precipitation phase of NiTiTa alloy changes from Ni3Ti of NiTi alloy to Ni(Ti, Ta)2. In addition, the phase transition temperature of the NiTiTa alloy is significantly increased, which makes the phase at room temperature change from the complete austenite phase (B2) to a mixed phase of austenite (B2) and martensite (B19'). Tensile tests show that the tensile strength of NiTiTa samples is increased by 9.5% compared with NiTi samples, but the elongation is decreased by 6.8%. The polarization curve results show that the NiTiTa alloy has a higher corrosion potential and a lower corrosion current density, which means a significantly improved corrosion resistance. This paper lays a theoretical foundation for promoting the application of NiTiTa alloys fabricated by WAAM technology in the biomedical field.

Multi-wire arc additive manufacturing (MWAAM) enabled customized production with high deposition efficiency and low cost as compared to the common wire arc additive manufacturing (WAAM) technology. In this paper, two titanium alloy components were prepared using the MWAAM technique, and the microstructures, mechanical properties, and wear behaviors of Ti–6Al–4V (TC4) alloy and Ti-6.5A1-3.5Mo-1.5Zr-0.3Si (TC11) alloy were investigated. The results showed that the microstructure distribution of TC11 alloy prepared by MWAAM was more intensive and the length and width of the lamellar α-Ti phase were significantly reduced compared with that of TC4 alloy. The polar densities corresponding to the texture in the two selected regions of the TC4 alloy and the TC11 alloy were 17.30 and 17.69, respectively. The proportion of the HAGBs of the TC4 sample and the TC11 sample were 99.07 % and 99.43 %, respectively. The average microhardness on the X–Y plane of TC4 and TC11 alloys were 316.17 HV and 366.14 HV, respectively, while the average microhardness on the Y-Z plane were 318.18 HV and 358.10 HV, respectively. The average compression yield strengths of TC4 and TC11 alloys were 836.61 MPa and 1088.33 MPa, respectively. The COFs of MWAAM TC4 and TC11 samples were stable at 0.479 and 0.455 under 20 N, respectively. The COFs of MWAAM TC4 and TC11 samples were stable at 0.472 and 0.432 under 60 N, respectively. The average yield strength, average ultimate strength, proportion of HAGBs, and microhardness of TC11 alloy were all higher than that of TC4 alloy. These results indicated that TC11 alloy had advantages over TC4 alloy in terms of mechanical properties and microstructure, with higher strength and deformation resistance. The properties of titanium alloy samples prepared by MWAAM were not lower than those of titanium alloy samples prepared by single wire WAAM, while MWAAM significantly better than single wire WAAM in deposition efficiency. The results obtained in this paper can help to prepare titanium alloy components with excellent mechanical properties more efficiently in MWAAM process.

This paper reports on the successful synthesis of a novel alumina powder with a unique rose-like structure composed of alumina platelets, using the molten salt method. The synthesized powder was then utilized to prepare alumina ceramic with impressive mechanical properties. The influences of the synthesizing temperature of alumina powder on the microstructure and mechanical properties of alumina ceramic are investigated in details. The results indicate that the alumina ceramic prepared using the rose-like powder synthesized at 800 °C exhibits a high relative density of 99.5 %, flexural strength of 408.2 ± 18.7 MPa, and fracture toughness of 6.14 ± 0.63 MPa m1/2. The work presented in this paper will provide a useful guideline for the preparation of high-performance alumina ceramic materials in the future.

In this paper, a novel coaxial continuous-pulsed dual-beam laser was proposed to join TC4 titanium alloy with QP980 high-strength steel, and magnesium alloy containing rare-earth elements (Mg-RE) was creatively as filler. The weld appearance, microstructure and mechanical properties of joints obtained by single-beam and dual-beam laser welding were compared and analyzed. And the evolution of bonding mechanism and the fracture mechanism with laser beam energy density was analyzed. The results showed that the appearance and mechanical strength of the joint obtained by dual-beam laser were better than that by single-beam laser. And the maximum tensile shear load of TC4/QP980 lap joint welded by dual-beam laser reached 303 N/mm, which was 124 % of that of single-beam laser welding. The bonding of Mg-RE with QP980 affected by temperature of laser welding and mainly depended on Gd and Y. They just diffused to QP980 under low power and reacted with Fe under high power. And the inter-diffusion of Zr of Mg-RE with Ti of TC4 produced to the bonding of Mg-RE with TC4. The roles of continuous laser and pulsed laser in dual-beam laser welding were revealed in this paper and it showed a great application potential of coaxial dual-beam laser welding technology in dissimilar metal joining.

This paper mainly explores the feasibility of using desert sand (DS) and recycled aggregate in cement-stabilized bases. Recycled coarse aggregate (RCA) and DS serve as the substitutes of natural coarse and fine aggregates, respectively, in cement-stabilized bases. A four-factor and four-level orthogonal test is designed to analyze the unconfined compressive strength, splitting tensile strength, and compressive resilient modulus. Furthermore, this paper investigates the effects of cement content, fly ash (FA) replacement rate, RCA replacement rate, and DS replacement rate on the road performance of cement-stabilized bases composed of RCA and DS. The test results reveal that the performance of cement-stabilized bases with partial RCA instead of natural coarse aggregate (NCA) and partial DS instead of natural fine aggregate satisfies the road use. The correlation and microscopic analyses of the test results imply the feasibility of applying DS and recycled aggregate to cement-stabilized bases. This paper calculates and evaluates the life cycle of carbon emissions of desert sand and recycled coarse aggregate cement-stabilized macadam (DRCSM) and finds that both DS and RCA can reduce the carbon emissions of CSM, which has a positive effect on improving the environment and solving the climate crisis. It is hoped that this paper can offer a solid theoretical foundation for promoting the application of DS and recycled aggregate in road engineering.

Before artificial ageing, extruded aluminium profiles are subjected to stretching with a small cold deformation in the range of 0.5–2%. This deformation improves the geometrical stability of the extruded product and causes changes in the microstructure of the profile, which leads to the strain hardening of the material after artificial ageing. The work has resulted in the creation of the prototype of an original device, which is unique in the world, for the dynamic stretching of the extruded profiles after quenching. The semi-industrial unit is equipped with a hydraulic system for stretching and a pneumatic system for cold dynamic deformation. The aim of this research paper is to produce advantageous microstructural changes and increase the strength properties of the extruded material. The solution of the dynamic stretching of the profiles after extrusion is a great challenge and an innovation not yet practised. The paper presents the results of microstructural and mechanical investigations carried out on extruded AlMgSi(Cu) alloys quenched on the run-out table of the press, dynamically stretched under different conditions, and artificially aged for T5 temper. Different stretching conditions were applied: a static deformation of 0.5% at a speed of 0.02 m/s, and dynamic deformation of 0.25%, 0.5%, 1%, and 1.5% at speeds of 0.05 and 2 m/s. After the thermomechanical treatment of the profiles, microstructural observations were carried out using an optical microscope (OM) and a scanning electron microscope (SEM). A tensile test was also carried out on the specimens stretched under different conditions. In all the cases, the dynamically stretched profiles showed higher strength properties, especially those deformed at a higher speed of 2 m/s, where the increase in UTS was observed in the range of 7–18% compared to the classical (static) stretching. The microstructure of the dynamically stretched profiles is more homogeneous with a high proportion of fine dispersoids.

Abstract In recent years, there has been an increasing use of Microbially Induced Calcite Precipitation (MICP) technology in ground improvement. Adding fiber to bio-cemented sand leads to significant improvements in its properties. This paper examines how coir fiber and microbially induced calcite precipitation (MICP) might be used to improve the engineering qualities of fine sand. The sand was mixed with Coir fiber at varying Fiber Contents (FC) of 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% by weight of sand. Additionally, varied Aspect Ratios (AR) of 45, 90, 136, 182, and 227 were considered. The mixture also included urease-producing bacteria (Sporosarcina Pasteurii), as well as solutions of urea and calcium chloride with 3M molarity. The untreated and treated sand samples were submitted to a Direct Shear Test (DST). The study found that the shear strength parameters, such as the angle of internal friction, increased by 1.1 times compared to standard fine sand. Additionally, the angle of internal friction (ϕ) of fiber-reinforced sand with MICP showed 1.4 times increase, while the cohesion values demonstrated a sixfold increase compared to MICP fine sand. It was determined that the optimal aspect ratio was 182, and the optimal fiber content was 0.3%. Moreover, the Scanning Electron Microscope (SEM) was utilized to examine the calcite formations present in the treated sand samples, and calcite precipitation was observed between the pores of the soils.

Cassava (Manihot esculenta Crantz) is one of the three major potato crops in the world. Consumption of cassava necessitates thermal processing, and the impact of such processing on the physicochemical and structural characteristics of cassava remained unknown. In this paper, three traditional thermal processing methods (boiling, steaming and frying) were used to heat-treat cassava. The physicochemical properties (chemical composition, pasting properties, thermal properties) and structural changes (microstructure, long-range ordering, and short-range ordering) of the processed cassava and untreated cassava was characterized by scanning electron microscopy, Fourier transform infrared spectrometry, X-ray diffractometer, and differential thermal scanning calorimetry. The findings indicated a significant reduction in the total starch content of cassava following diverse heat treatments, accompanied by a notable increase in amylose content (P

The recent interest in multifunctional materials with tailorable performances led to the formulation of novel polymer blends, with enhanced properties with respect to traditional plastics and showing economical advantages compared to the synthesis of new polymers. However, polymer blends are immiscible in most cases, and proper compatibilization is therefore needed to obtain an alloy with suitable performances. Beside the traditional compatibilization approaches (i.e., addition of graft or branched copolymers, reactive compatibilization), a novel technique has recently emerged, based on the insertion of micro- and nanostructured inorganic fillers within polymer blends.Therefore, the aim of this review is to give an overview about the role played by nanofillers on the compatibilization of polymer alloys. A survey of the most important papers in literature on this topic will be presented, trying to correlate the microstructural features of nanofilled blends to their physical properties. After an introduction on the general aspects of polymer alloys in Chapter 1, the most relevant compatibilization strategies will be presented in Chapter 2, with particular emphasis on the compatibilization induced by micro- and nanostructured fillers. Chapter 3 will be focused on the nanofiller induced compatibilization, and several examples of thermoplastic, thermosetting and elastomeric nanofilled blends will be presented. Considering the increasing importance of biopolymers and of their blends in the modern industry, in Chapter 4 it will be shown how nanofiller induced compatibilization could be successfully applied also to bioplastics based alloys. Due to the recent environmental concerns on the polymer waste management and the difficulties in the plastics sorting operations, in Chapter 5 it will be demonstrated that nanomodification of recycled plastics can lead to blend recyclates with good compatibility and suitable physical properties. The key aspects of the nanofiller induced compatibilization in polymer blends and the future perspectives will be summarized in Chapter 6.

Ceramic cores for high-pressure turbine airfoil blades in aircraft engines are characterised by very complicated shapes and the presence of small diameter holes and thin long grooves. In this paper, eight starting powder mixtures having different contents of fused silica, zirconium silicate, alumina and borosilicate glass were used for preparation of core material. The composition, which satisfies every demand for core application in the investment casting of high-pressure turbine blades, contains 69.0wt.% fused silica, 13.0 wt.% zirconium silicate, 12.0wt.% alumina and 6.0wt.% borosilicate glass. This material was characterised by a mechanical strength of 33.1MPa, a coefficient of thermal expansion of 2.56 × 10−6 1/K, surface roughness of 1.8 μm, shrinkage of less than 0.8% and an average pore size diameter of 2.7 μm. The thin-walled ceramic cores were formed by the high-pressure injection moulding method, which required the selection of a thermoplasticiser, feedstock formulation and determination of the optimal processing conditions protecting the injected cores from defects and deformation. The post-shaping process of the cores included both water and thermal debinding, sintering, precision machining and dimension measurements.

The paper examines the effect of precipitation hardening temperature on selected properties of AlSi5Cu2Mg alloy alloyed by 0.20 wt.% of Zr. The newly developed AlSi5Cu2Mg alloy intended for cylinder head castings is specific due to its limited Ti content, which prevents the use of standard Al-Ti-B type grain refiners. Zr added in the form of AlZr20 master alloy acts as a grain refiner. The grain refinement effect of Zr positively affects the mechanical properties. However, the physical properties defining the lifetime of cylinder head castings are not affected by the presence of Zr-rich phases. For this reason, the research focuses on the proposal of the optimal T6 heat treatment procedure in order to positively influence the physical and mechanical properties of the AlSi5Cu2Mg alloy. For the research, four T6 thermal regimes with graduated aging temperatures by 20°C from 180 to 240°C ± 5°C were selected. The results showed that increasing aging temperature positively affects physical properties, especially thermal conductivity, and mechanical properties of Rm, Rp0.2, and HBW. On the other hand, with increasing aging temperature up to 220°C ± 5°C, a negative decrease in ductility was achieved. Optimum ductility of, especially, AlSi5Cu2Mg alloy with 0.20 wt.% Zr was achieved by the T6-240 thermal regime. Optimal combination of thermal conductivity and mechanical properties of the AlSi5Cu2Mg alloy with 0.20 wt.% Zr was achieved by the T6-240 heat treatment due to the requirements placed on cylinder head castings.

Although known for many years, HSLA steels are still of considerable interest to researchers. The unique properties offered by the presence of micro-additives Nb, V, Ti in these steels are widely used in a variety of constructions – from the automotive industry, through the transport of media such as oil or gas, to large structures. Unfortunately, much of the research only concerns the theoretical sphere or does not go beyond the area of semi-industrial research. Research on an industrial scale, supported by industrial trials, is relatively scarce. This is certainly due to the very high costs of such research, but also to the rather limited number of places where HSLA steels are mass produced. This paper presents and systematizes research from the last three years into the thermo-mechanical rolling of HSLA steels. The review is divided according to the successive stages of the production process. The work forms the author’s basis for further research in this area.

High-density defects in additively manufactured components cause poor mechanical properties and premature failure. The present paper aims in minimizing defects in laser metal deposition (LMD) of high-strength aluminium alloy 7075. The effects of different TiC nanoparticle contents on the defects (crack and porosity), microstructural (grain size and morphology) and mechanical (tensile strength and hardness) properties were investigated systematically. The sizes and densities of cracks and surface porosities were reduced by increasing TiC nanoparticle content. The grain areas were reduced and ultimate tensile strength increased by increasing the TiC nanoparticle content. The present results clearly prove that the TiC content plays a substantial role in tailoring microstructure and improving the reliability and mechanical properties of LMD Al alloy 7075.

In the realm of military and defence applications, exposure to radiation significantly challenges the performance and reliability of solder alloys and joints in electronic systems. This comprehensive review examines radiation-induced effects on solder alloys and solder joints in terms of microstructure and mechanical properties. In this paper, we evaluate the existing literature, including experimental studies and fundamental theory, to provide a comprehensive overview of the behavior of solder materials under radiation. A review of the literature highlights key mechanisms that contribute to radiation-induced changes in the microstructure, such as the formation of intermetallic compounds, grain growth, micro-voids and micro-cracks. Radiation is explored as a factor influencing solder alloy hardness, strength, fatigue and ductility. Moreover, the review addresses the challenges and limitations inherent in studying the effects of radiation on solder materials and offers recommendations for future research. It is crucial to understand radiation-induced effects on solder performance to design robust and radiation-resistant electronic systems. A review of radiation effects on solder materials and their applications in electronics serves as a valuable resource for researchers, engineers, and practitioners in that field.

Nickel-base alloy is a type of metal material with excellent properties and is widely used in many fields. However, in the harsh environment of the acid solution, corrosion causes the reduction of the service life of the alloys, thereby limiting the alloys' use and development. In this paper, the effect of Chromium (Cr) content on the microstructure and corrosion behavior of nickel-based alloys in hydrochloric acid (HCl) was studied by scanning electron microscopy (SEM), energy dispersive spectrum (EDS), electron backscatter diffraction (EBSD) and electrochemical workstation. Meanwhile, X-ray photoelectron spectroscopy (XPS) was used to investigate the composition and properties of the surface passive films. For the Cr20 and Cr30 alloys with a single face-centered cubic (FCC) structure, the Cr2O3 content in the passive films increased with the Cr content, effectively improving the corrosion resistance. As the Cr content continued to increase, the second phases having a body-centered cubic (BCC) lattice were precipitated both in the Cr40 and Cr50 samples, inducing microgalvanic corrosion, thus deteriorating the corrosion resistance. XPS results showed that, in the Cr30 alloy, the relative content of Cr2O3 and the bound water were the highest, indicating that its passive film had the best corrosion resistance. For the passive film, the pitting resistance was related to Cr content, appropriate Cr content improved the corrosion resistance.

For the development of new energy automobile industry and the trend of automobile lightweight have put forward a huge demand for high-strength lightweight materials, so developing high strength aluminum alloys is particularly momentous. As the most widely used aluminum alloy, 6000 series aluminum alloys (Al–Mg–Si alloys) have the advantages such as better mechanical properties, outstanding welding properties, excellent formability and fine processing capability, and therefore have obtained great attention as the structural materials. In addition, the Al–Mg–Si alloys with low density and corrosion resistance not only reduce the total weight of the car, but also extend the service life when subjected to chemical corrosion, which effectively achieve energy saving and emission reduction. This paper summarizes the research progress of 6000 series aluminum alloys, in particular, and reviews the methods of microalloying and particle strengthening, and their effects on the microstructure and properties of the alloy, thus providing a reference for the subsequent development of high-performance aluminum alloys in automobile and aerospace industries.

In general, the Ti–6.5Al–2Zr–1Mo–1V (TA15) components fabricated via laser powder bed fusion (L-PBF) exhibit high strength and low ductility. Herein, we report a novel approach to enhance the comprehensive mechanical properties of L-PBF TA15 alloy by adjusting the laser power. Samples processed using the optimal laser power exhibit a grid structure of alternating wide and narrow prior-β grains (PBGs), the inside of which is composed of a fully martensitic microstructure. The paper discusses in detail the alterations in the microstructure of samples processed at both low and high laser powers, clarifying the relationship between microstructure and mechanical properties. Thinner martensite contributes to higher strength, while a homogenous microstructure improves ductility. These findings provide valuable insights for controlling microstructure and achieving strength-ductility synergy in L-PBF additive manufacturing of titanium alloys.

Magnesium alloys have received a lot of attention in aerospace, automotive, electronic communications and other fields due to their low density, high specific strength and damping performance. However, magnesium alloy sheets prepared by conventional thermomechanical processing usually have a strong basal texture, resulting in poor formability. In this paper, Mg–Mn–Ce alloys with good plastic forming ability were prepared by studying and optimizing the annealing process. Under the low-temperature annealing condition, it can promote the static recrystallization and grain refinement of Mg–Mn–Ce alloy, and also eliminate the internal stress. With the increase of annealing temperature, a large amount of dispersed Mg12Ce as a stable second phase effectively hindered the grain boundary migration, while the nanoscale α-Mn forms a fine second phase to inhibit grain growth, and both of them together greatly stabilize the deformation structure of the alloy, and maintain a good grain organization under the condition of annealing temperature of 300 °C and holding time of 30 min. The present work also improves the Arrhenius constitutive equation for the Mg–Mn–Ce alloy with respect to the degree of deviation, which significantly improves the accuracy of the model in predicting the thermoforming behavior. Meanwhile, to address the shortcomings of the traditional forming method of magnesium alloy, the processing process of spreading the centrifugal casting tube flat is proposed, the forming process is simulated, and the location of easy breakage in the forming process is predicted. These findings provide microanalytical support for the improvement of forming properties of magnesium alloys by annealing.

In this paper, (0.2–1 wt%) Yb was added to improve the tensile properties and high-cycle fatigue behavior of the as-cast and as-extruded Mg-10Li-5Zn-0.5Er alloys. It is found that Yb mainly affects the mechanical properties of the alloy by changing the grain size, type and morphology of the second phases. Yb mainly exists in the formation of Mg2Yb and Mg-Zn-Yb phases in the metallographic structure. With the addition of Yb, the grains are refined and these Yb-containing phases replace the large-sized MgLiZn phase to be enriched at the grain boundaries. While the addition of excess Yb reduces the number of small-sized MgLiZn phases in the grain, thus reducing the alloys’ mechanical performance. After extrusion, the small-sized MgLiZn phase is refined and the number increases, which effectively improves the tensile and fatigue strength of the alloy. The fatigue strength is mainly affected by the number and morphology of the second phase, positively correlated with the strength. Balanced in grain size and number and size of second phases, the extruded alloy with 0.2Yb added exhibits excellent mechanical properties with the yield strength, ultimate tensile strength and elongation of 292 MPa, 303 MPa and 11.7%, and an fatigue strength of 130 MPa.

Magnesium alloy is one of the most widely used lightweight structural materials, and the development of high strength-toughness magnesium alloy is an important research field at present and even in the future. The preparation process parameters of magnesium alloy directly affect the microstructure of the magnesium alloy, and then determine the properties of the magnesium alloy. The cooling rate has important effects on the microstructure and properties of the magnesium alloy, and is an important preparation process parameter that cannot be ignored. Both the cooling rate from liquid phase to solid phase and the cooling rate of the magnesium alloy after heat treatment will change the microstructure of the magnesium alloy. Furthermore, the properties of magnesium alloy will be affected. In this paper, the effects of cooling rate on the solidification behavior, the rheological behavior, the change of microstructure (the solid solution of alloying elements in matrix, the composition, size, distribution and morphology of second phase, the diffusion and segregation of alloying elements, the grain size, the formation and morphology of dendrite, etc.), and the effects of cooling rate of magnesium alloy after heat treatment on the microstructure and stress distribution are reviewed. The reasons for the divergence about the influence of cooling rate on the microstructure of magnesium alloy are analyzed in detail. The effects of cooling rate on the mechanical properties, corrosion resistance and oxidation resistance of magnesium alloy are also analyzed and discussed deeply. Finally, the new methods and approaches to study the effects of cooling rate on the microstructure and properties of magnesium alloy are prospected.

Wire and arc additively manufactured aluminum alloys are prone to porosity, leading to poor mechanical properties in samples, which hinders their broad industrial application. Laser and arc hybrid processes have garnered increasing attention for their potential to reduce porosity, stabilize the arc, and enhance deposition efficiency. This paper investigates the porosity, element distribution, microstructure evolution, and mechanical properties of 2319 aluminum alloy produced through the laser and cold metal transfer (laser-CMT) hybrid additive manufacturing process. In comparison with the as-deposited samples, the laser-CMT hybrid process decreases porosity, enhances element distribution, mitigates Cu element segregation, and results in increased θ′′ phase precipitation. Following T6 heat treatment, the ultimate tensile strength (UTS), yield strength (YS), and elongation of the x-direction specimens from the laser-CMT hybrid process are 450.0 MPa, 318.1 MPa, and 10.0%, respectively. These values are 11.27%, 7.03%, and 36.65% higher than those of the as-deposited samples. To validate the findings, a large-scale load-carrying frame for a commercial aircraft was fabricated, demonstrating the efficacy of the process. The paper also presents a detailed analysis of the strengthening mechanism. Samples deposited using the laser-CMT method exhibit reduced porosity and excellent mechanical properties, making this process promising for a wide range of applications.

Aluminum alloys are widely used in the fields like aerospace, automotive and manufacturing industries due to their excellent comprehensive performances and low mass and density. With the rapid development of the industries above mentioned, the requirements of aluminum alloys properties are increasingly raised. Therefore, it is especially significant to choose reasonable treatment methods to upgrade the related performances of aluminum alloys. As a green, low-cost and no pollution new heat treatment process, deep cryogenic treatment (DCT) can significantly improve the microstructures and performances of the metals with little variation in their sizes and shapes. The present paper summarizes the characteristics and mechanisms of the DCT influence on the structure-performance evolutions of aluminum alloys. When the DCT parameters are selected appropriately, ultra-low temperature can lead to refinement and preferred orientation of grains, increase of dislocation density and optimization of secondary phase distribution for aluminum alloys. Besides, mechanical properties, residual stress, corrosion resistance, wear resistance and electrical conductivity of aluminum alloys can be considerably improved due to the various microstructure evolutions induced by DCT. The present paper not only concludes major findings of the previous researches but also suggests future recommendations for aluminum alloys processed by DCT.

Extruded magnesium alloy bars are susceptible to uneven microstructure after the heat treatment process, which is characterised by coarse grain size in the surface, thus affecting the further processing properties of the overall bars. In this paper a new cyclic rotating-bending (CRB) process is proposed to improve the microstructure by achieving a gradient plastic deformation of the bars from the surface to the core. The paper is based on finite element simulations to qualitatively and quantitatively investigate the plastic strain distribution and evolution in the middle radial section of the bar under different CRB processes. In addition, the influence on the microstructure distribution under the processes is also further clarified. The results show that during CRB deformation, the plastic strain in the middle radial section of AZ31B magnesium alloy bars gradually decreases from the surface to the core radially, and the plastic strain in the surface is significantly positively correlated with the bending angle and the period of rotation. When the bending angle reaches 150°–170° and the period of rotation reaches 30 r, the section of the bars is fully plastic deformed. Simultaneously, compared to the initial microstructure, significant twinning deformation occurs in the surface of the bars after different CRB processes, which further promotes grain refinement.

Egg yolk is rich in nutrition and complex in structure. Its major components are egg yolk granules (EYGs) and egg yolk plasma (EYP). The physicochemical properties and microstructures of egg yolk and its components are greatly affected by different treatments during processing, and in turn affect their functional properties. Therefore, this paper reviews the effects of different treatments including salting, alkali treatment, heat treatment and enzymatic treatment on the physicochemical properties (surface hydrophobicity, oil exudation, and protein solubility) and microstructure of egg yolk as well as EYGs and EYP. In addition, this paper discusses the functional changes of egg yolk and its components after different treatments. We expect this review to provide theoretical support for future research on the physicochemical properties and microstructure of egg yolk components and on their effects on the functional properties of egg yolk components.

Multi-walled carbon nanotubes (MWCNTs) are a high-quality interlamination reinforcement material, but the high viscosity of polyetheretherketone (PEEK) prevents good fusion between MWCNTs and PEEK. This study proposes a method to achieve the complete integration of MWCNTs and PEEK through the preparation of a composite film using the vacuum suction filtration (VSF) method and optimizes the process parameters. An orthogonal experiment with three factors (filter paper pore size, ultrasonic dispersion time, and PEEK content) at three levels is designed, and mechanical performance testing and microscopic morphology observation are conducted. The influence of the three factors of filter paper pore size, ultrasonic time, and PEEK content on the elastic modulus and tensile strength of the film is investigated. The results are a filter paper pore size of 0.45 μm, ultrasonic time of 8.3 h, and PEEK content of 336.524 mg. The mechanical performance obtained under the optimal process parameters are an elastic modulus of 2437.5723 MPa and a tensile strength of 46.5196 MPa. This optimal process increases the elastic modulus by 12.3152% while maintaining a high tensile strength.

This paper presents the influence of adding rinsed ilmenite mud waste (R-MUD) on the microstructure of Portland cement composites, compared to similar composites containing fly ash (FA). The aim of the study is the assessment of the pozzolanic activity of ilmenite mud waste by its impact on the microstructure of the cement matrix in comparison to the undoubted pozzolanic activity of fly ash. The presented test results include pore size distribution, phase composition, pozzolanic activity using thermal analysis, R3 bound water test, and microstructural analysis using scanning electron microscopy (SEM). Tests were performed on mortars cured for up to 360 days. The results presented in this paper have shown that R-MUD has a pozzolanic activity level similar to FA or better, which influences pore size distribution in the composite and its microstructure. During the curing process, the microstructure of composites containing R-MUD became more compact and sealed than those with FA, which might also increase their durability. The results of the R3 tests have proven the pozzolanic activity of R-MUD but its level was lower than FA. R-MUD might be a useful substitute for fly ash, especially given the lack of good-quality fly ash on the market.

This study evaluates the potential use of discarded plasterboard paper as fibers from buildings to reinforce concrete. Various concentrations of wastepaper fibers (0.5%, 1%, 1.5%, 2%, and 2.5% by weight of the binder) were investigated in this research. To mitigate the water absorption effect of the paper fibers, metakaolin was employed as a partial cement replacement. The results demonstrate that the inclusion of the wastepaper fiber enhances the mechanical and durability performance of the concrete. The optimal fiber proportion was identified as 1%, leading to a 29% increase in the compressive strength, a 38% increase in the splitting tensile strength, a 12% decrease in the water absorption, and a 23% decrease in the drying shrinkage with respect to the concrete containing 20% metakaolin. However, exceeding this optimal fiber content results in decreased mechanical and durability properties due to the fiber agglomeration and non-uniform fiber distribution within the concrete matrix. Based on the microstructural analysis, the improved performance of the concrete is ascribed to decreased porosity, more refined pore structure, and reduced propagation of microcracks within the concrete matrix in the presence of wastepaper fiber. According to the results, concrete containing 20% metakaolin and 1% wastepaper fiber exhibits durability and mechanical properties comparable to those of the traditional concrete. This finding highlights the significant promise of reducing dependency on conventional cement and incorporating suitable recycled materials, such as discarded plasterboard, and secondary by-products like metakaolin. Such a strategy encourages the preservation of resources, reduction in carbon dioxide emissions, and a decrease in the ecological footprint resulting from concrete production.

In this paper, it was found for the first time that with Sr addition in Al–Si–Mg–Ce alloy, the morphology of eutectic (Si) can be modified from branch to fine fibrous, while the bulk-like Al2Si2Ce phase may replace the elongated needle-like one. Moreover, Mg was observed to segregate along the (Al)/Al2Si2Ce interface and Sr was found to concentrate in the interior of Al2Si2Ce phase. Such heterostructured Sr–Al2Si2Ce was also supported by first-principles calculations. The synergistic morphology modification of eutectic (Si) and Al2Si2Ce phases by Sr addition stimulated the simultaneous improvement in strength and ductility in Al–Si–Mg–Ce alloy.

In this paper, the effects of Hf addition on the mechanical properties, electrical conductivity and microstructure of Cu-Sn-P alloy were investigated. The results show that the Hf addition can enhance the mechanical properties and electrical conductivity of Cu-Sn-P alloy. The alloy with 0.05 wt% Hf exhibits the best comprehensive performance with yield strength of 625 MPa, tensile strength of 661 MPa and electrical conductivity of 16.8 %IACS. Compared with the Cu-Sn-P alloy without Hf addition, the yield strength and tensile strength are increased by 8.4% and 7.8%, and the electrical conductivity is increased by 24.4%. The increase in the strength of Hf-added alloy can be attributed to the synergistic effect of multiple strengthening mechanisms, including fine grain strengthening, twin strengthening, dislocation strengthening, precipitation strengthening and Σ3n (n = 1, 2, 3) grain boundary strengthening. Moreover, the Hf-P precipitates can be observed in the Hf-added alloy. According to the amount of Hf addition, these precipitates can manifest as the fine HfP2 phase and the coarse HfP phase. The formation of Hf-P precipitates contributes to the precipitation strengthening and the purification of Cu matrix, thus contributing to the improvement of strength and conductivity.

This paper evaluates the corrosion behavior of 316L stainless steel (SS316L) matrix composites reinforced with 3% yttria-doped zirconia (3Y·ZrO2), fabricated using the spark plasma sintering. Four different compositions were produced (SS316L, SS316L-5%vol. 3Y.ZrO2, SS316L-10% vol. 3Y.ZrO2, and SS316L-20% vol. 3Y.ZrO2) and primarily assessed for their corrosion resistance evaluated via immersion tests and electrochemical impedance spectroscopy (EIS). Additionally, densification, surface morphology, microstructure and mechanical properties were characterized as complementary. Densification was measured using the Archimedes method, while surface and microstructural characteristics were analyzed using optical and scanning electron microscopy. Mechanical properties were determined through microhardness testing. The results indicate that higher 3Y·ZrO2 content decreases densification and induces porosity, which contributes to localized corrosion. Despite the presence of porosity, microhardness improved with increasing 3Y·ZrO2 content. Additionally, immersion and EIS tests revealed that 5% of 3Y·ZrO2 enhances corrosion resistance. However, in composites with 10% and 20% 3Y·ZrO2, porosity compromises corrosion resistance by degrading passivation. Notably, composites with 5% 3Y·ZrO2 demonstrated significantly better corrosion resistance compared to pure SS316L and the other compositions, highlighting their potential for practical applications.

Duplex stainless steel (DSS) is widely used in the marine, petroleum, chemical, automotive, and other fields owing to its excellent mechanical properties and corrosion resistance. However, the research on duplex stainless steel prepared by additive manufacturing is still limited. In this paper, high-density 2507 DSS was successfully prepared by selective laser melting (SLM) additive manufacturing. The effects of energy density on the formability, phase composition, microstructure and corrosion properties of SLM 2507 DSS were investigated. The results showed that with the decrease of the energy density, the density of the specimen increases first and then decreases, and the density achieves 99.18% with the energy density of 190.5 J/mm3. The types of phases are not affected by the energy density, i.e., all 2507 DSS samples prepared by SLM showed a ferrite phase. The YOZ (parallel to the building direction) plane of the SLM 2507 DSS samples showed predominantly columnar grains attributed to the high temperature gradient and epitaxial growth characteristics. With the increase of energy density, the average grain size decreases slightly from 16.97 μm to 15.78 μm, the KAM value decreases slightly from 1.15 to 1.05, and the low angle grain boundaries (LAGBs) increase significantly from 68.4% to 74.8%. The SLM 2507 DSS sample exhibited excellent corrosion resistance. The self-corrosion potential of the sample is 136 mV and the self-corrosion current density is 2.066 × 10−8 A/cm2 at the maximum density. This investigation provides a new approach for the preparation of super duplex stainless steel, which can provide a theoretical basis and guidance for industrialized application.

Under mining conditions, the micro crack structure of the composite strata of the coal seam floor affects the uplift and seepage of the groundwater in the underlying high water pressure aquifer, and its complexity is of great significance for the prediction and early warning of the water disaster in the coal seam floor. In this paper, a total of 57 groups of rock samples extracted from three adjacent mines in the east of Pingdingshan Coalfield are taken as the object. Based on the comprehensive information of SEM image acquisition and N2 adsorption test, the fissure ratio of rock stratum area, equivalent crack diameter of rock stratum, fractal dimension value of fissure area, specific surface area, crevice volume and its fractal dimension are the main controlling factors. Using entropy weighted TOPSIS mathematical model, the complexity of the micro fracture structure of the composite rock stratum between the Ji16-17 coal seam and the Cambrian limestone top interface is quantitatively evaluated. The results show that the micro crack structure of the composite strata in the floor of the Ji16-17 coal seam is very simple, simple, medium, complex and extremely complex, accounting for 25.00%, 21.43%, 39.29%, 7.14% and 7.14% respectively. The micro crack structure of the composite strata in the study section is relatively uncomplicated; Compared with the four rock sections, the order of the quantitative mean value of the complexity of the rock stratum micro fracture structure is: L1−L2 limestone section>L5−L7 limestone section>sandstone section>bauxite mudstone section. The complexity of the rock stratum micro fracture structure better reflects the development of the rock stratum fracture. The paper considers the coupling effect of multiple factors on the composite rock stratum, realizes the quantitative classification and zoning discrimination of the micro crack structure in the vertical section of the composite rock stratum, which is of great significance for accurately describing the aquifer performance of the composite rock stratum in the coal seam floor and scientifically guiding the prevention and control of the water hazard in the coal seam floor.

Magnesium alloys, as the lightest commercial metal engineering structural materials, have good application prospects in the automotive, communication equipment, aerospace, and military industries because of their light specific gravity, high strength properties such as specific strength and stiffness, shielding from electromagnetic radiation, and easy recycling. In this paper, starting from the density and microstructure of magnesium alloy, the mechanical properties and corrosion resistance of magnesium alloy are proposed to measure the indexes, and the corresponding prediction model is constructed. Then, fine-crystal magnesium alloys are prepared sequentially by ingot casting and isometric channel extrusion, and then the microstructure of magnesium alloys is observed by scanning electron microscope and transmission electron microscope to extract the micro-parameters of magnesium alloys. A martensitic phase transition topology model was introduced to determine the macroscopic shape strain of magnesium alloy crystals. Complex network analysis is used to quantify the topological structure parameters of a magnesium alloy network in terms of degree, clustering coefficient, and average path length. Finally, the correlation between the macroscopic features and microstructure of magnesium alloy is explored with the obtained data, and the mechanical and corrosion resistance properties of magnesium alloy are analyzed through simulation experiments by combining them with the constructed prediction model. The microstructural topological characteristic parameters of magnesium alloys show that when the pressure is 50 kPa, the average path length after weighting decreases from 36.012 × 10−3 to 34.015 × 10–3, and the force transfer efficiency is gradually increasing. The AZ31 alloy samples obtained from casting in this paper have a capacitive arc diameter of about 1600 Ω-cm² and the best corrosion resistance among the tested samples.

This paper presents the use of a Gaussian neighborhood mode filter for predicting grain growth in a manner similar to the solutions obtained by a Monte Carlo Potts model. This flexible grain growth model can quickly utilize modern, computationally optimized data science strategies on graphics processing units to simulate grain growth up to 100 times faster than the state-of-the-art, publicly available Monte Carlo Potts model. We show that, given the correct neighborhood, the mode filter can replicate normal grain growth in two or three dimensions. In addition, the paper briefly demonstrates the ability to model limited anisotropic in grain boundary energy and mobility. Anisotropic grain boundary energy is modeled by defining a weighted mode filter operation. Anisotropic grain boundary mobility is modeled by scaling and orienting the Gaussian neighborhood in a particular direction.

This study focuses on collapsible soil from hyper-arid regions in the south of Algeria (Zeribet El Oued, Biskra). A physical characterization of the studied soil was performed which revealed that the soil samples are loess. After this, an experimental study was done on the influence of the sodium silicate solution (Na2SiO3) at different doses on the collapse potential (CP) and the microstructure of the material. The microstructure investigation was made through a scanning electron microscope (SEM) observation.The main results of this study show that the treatment of collapsible soil with sodium silicate has led to a significant reduction of the collapse potential, exceeding 87%. An effective treatment is obtained with a sodium silicate solution at the optimal dose of 0.8 mol.L−1. The SEM observations have revealed micro-structural transformations which are correlated to changes to geotechnical behavior.

This paper gives an overview of findings, connected with metallurgical activity, at the Pržanj archeological site near Ljubljana, Slovenia. More than 230 kg of slag and other remains connected with early medieval (from the 5th to the 12th century AD) metallurgical activities was found at the excavation site. The remains were grouped into four categories, i.e., furnace remains, ore, slag and a ferrous product, and analyzed in detail to obtain their chemical composition, microstructural characteristics, and mineral phase composition. The furnace wall remains, identified by their morphology and chemical composition, revealed an intensive iron processing activity at the site. The iron ore at the site was identified as goethite (FeO(OH)), a surprising find in Slovenia where limonite is typically used, and its presence suggests the potential exploitation of local bog iron ore, given the site’s geological context. Abundant slag remains at the site, identified by their shape, molten microstructure, and mineral components like wuestite, fayalite, and hercynite, indicated sophisticated smelting practices, including the use of CaO-rich materials to lower the melting temperature, a technique likely preserved from antiquity. Findings of ferrous products at ancient metallurgical sites are rare due to their value, but the discovery of a corroded iron bloom conglomerate at this site, initially mistaken for furnace remains, highlights the challenges in identifying small, corroded ferrous fragments that are often misidentified as ore. The results indicate extensive metallurgical activity at the excavation site, marking it as the first documented early medieval iron smelting production site in Slovenia.