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This study measured the decrease in some mechanical properties of kraft paper used in packaging and bag production by examining the colour changes occurring in accordingly prepared standard samples subjected to UV influence. Thus, it is aimed to predict the mechanical properties of packages that have been exposed to sunlight over long periods of time with the colour change measurement, which is a non-destructive test, without the packaging deformation. Since there are mechanical differences between the cross-machine width and machine length of fabricated papers, these were measured separately. Measurements were made on papers exposed to UV for 0, 120, 240, 360, 480, 600, and 720 h. Tensile strength, strain at break, and tensile energy absorption (TEA) values were measured and also predicted for the kraft paper. For the prediction, the time and colour change values were used as independent variables, whereas the mechanical properties were taken as the dependent variables. The relationship between the time and colour change and the tensile strength, strain at break, and TEA variables in both the crossmachine and the machine directions were significant at the 5% level, and the R2 values were within acceptable limits. The results showed that the mechanical properties of the papers under UV effect decreased proportionally with the increase of the UV time. [ABSTRACT FROM AUTHOR]

The effects of nanoclay were studied relative to the physical, mechanical, optical, and morphological properties of chemimechanical pulping papers. Nanoclay was incorporated at 0%, 2%, 4%, 6%, 8%, or 10%. To increase the retention, 1% cationic starch was used in all test papers. Handsheets (60 g/m2 in weight) were tested to determine their physical, mechanical, optical, and morphological properties. Up to 2% nanoclay increased the tensile strength; at values greater than 2%, the tensile strength decreased. The addition of up to 4% nanoclay increased roughness; between 4% and 10% nanoclay, roughness decreased. With 10% nanoclay, the tear strength, burst strength, and brightness decreased, but the air resistance, opacity, and yellowness increased. Scanning electron microscopy showed that the nanoclay filled the pore spaces between fibers, thus increasing air resistance. X-ray diffraction patterns indicated an intercalated structure. [ABSTRACT FROM AUTHOR]

The potential utilization of melamine impregnated paper (MIP) waste in thermoplastic composites was investigated. Composites were also manufactured utilizing wood flour (WF) at the same filler rates for comparison. The composites were manufactured using a compression molding method. The effects of filler type and filler rate on the mechanical properties of low-density polyethylene (LDPE)-based composites were evaluated. Mechanical properties, such as tensile and flexural strengths, were determined in accordance with ASTM D638 (2001) and ASTM D790 (2003), respectively. Results showed that filler type and filler content had significant effects on all mechanical properties investigated. Both fillers improved all mechanical properties except for tensile strength and elongation at break of LDPE. In conclusion, MIP waste has a potential to be utilized in thermoplastic-based composite manufacturing and might generate some economic and environmental benefits. [ABSTRACT FROM AUTHOR]

Paper money passes through various environments during its life span, causing its physical, chemical, and optical properties to change. More than 90% of paper money worldwide is composed of natural cotton fiber. The present study examined the properties of paper money made of bleached softwood kraft fibers or its blends with cotton fibers, where nanofibrilled cellulose was employed as a strengthening agent. Nano-cellulose was added at 4 levels: 0, 0.3, 0.6, and 0.9%. Handsheets with a basis weight of 90 g·m-1 were made by mixing the pulp furnish with nano-cellulose in the identified percentages, and the physical and mechanical properties of the handsheets were tested. By increasing the amount of nano-cellulose up to 0.9% in cotton pulp, the tensile strength, bursting resistance, tear resistance, and resistance to folding endurance were increased by 33, 33.5, 6.6, and 63.2%, respectively, compared with the control sample. The addition of nano-cellulose up to 0.9% in cotton pulp increased the surface smoothness by up to 13.5% compared with the control sample, and porosity and water absorbance decreased by 16.6 and 4%, respectively, in comparison with the control sample. By increasing nano-cellulose up to 0.9% in cotton pulp, the opacity, brightness, and whiteness were decreased by 0.1, 1, and 4%, respectively. The SEM results indicated that the increased nano-cellulose percentage led to decreased porosity. [ABSTRACT FROM AUTHOR]

Ultra-high-performance concrete (UHPC) is a cementitious composite combining high-strength concrete matrix and fiber reinforcement. Standing out for its excellent mechanical properties and durability, this material has been widely recognized as a viable choice for highly complex engineering projects. This paper proposes (i) the review of the influence exerted by the constituent materials on the mechanical properties of compressive strength, flexural tensile strength, and elastic modulus of UHPC and (ii) the determination of optimal quantities of the constituent materials based on simplified statistical analyses of the developed database. The data search was restricted to papers that produced UHPC with straight steel fibers at a content of 2% by volume. UHPC mixture models were proposed based on graphical analyses of the relationship of constituent materials versus mechanical properties, aiming to optimize the material's performance for each mechanical property. The results proved to be in accordance with the specifications present in the literature, characterized by high cement consumption, significant presence of fine materials, and low water-to-binder ratio. The divergences identified between the mixtures reflect how the constituent materials uniquely impact each mechanical property of the concrete. In general, fine materials were shown to play a significant role in increasing the compressive strength and flexural tensile strength of UHPC, while water and superplasticizers stood out for their influence on the material's workability. [ABSTRACT FROM AUTHOR]

The primary focus of the current paper centers on the microstructures and mechanical properties exhibited by a Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt. %) (TNZTSF) alloy that has been produced through an intricate synthesis process comprising cold-crucible induction in levitation, carried out in an atmosphere controlled by argon, and cold-rolling deformation (CR), applying systematic adjustments in the total deformation degree (total applied thickness reduction), spanning from 10% to 60%. The microstructural characteristics of the processed specimens were investigated by SEM and XRD techniques, and the mechanical properties by tensile and microhardness testing. The collected data indicate that the TNZTSF alloy's microstructure, in the as-received condition, consists of a β-Ti phase, which shows polyhedral equiaxed grains with an average grain size close to 82.5 µm. During the cold-deformation processing, the microstructure accommodates the increased applied deformation degree by increasing crystal defects such as sub-grain boundaries, dislocation cells, dislocation lines, and other crystal defects, powerfully affecting the morphological characteristics. The as-received TNZTSF alloy showed both high strength (i.e., ultimate tensile strength close to σUTS = 705.6 MPa) and high ductility (i.e., elongation to fracture close to εf = 11.1%) properties, and the computed β-Ti phase had the lattice parameter a = 3.304(7) Å and the average lattice microstrain ε = 0.101(3)%, which are drastically influenced by the applied cold deformation, increasing the strength properties and decreasing the ductility properties due to the increased crystal defects density. Applying a deformation degree close to 60% leads to an ultimate tensile strength close to σUTS = 1192.1 MPa, an elongation to fracture close to εf = 7.9%, and an elastic modulus close to 54.9 GPa, while the computed β-Ti phase lattice parameter becomes a = 3.302(1) Å. [ABSTRACT FROM AUTHOR]

The early strength of geopolymers (GPs) and their composites is higher, and the hardening speed is faster than that of ordinary cementitious materials. Due to their wide source of raw materials, low energy consumption in the production process, and lower emissions of pollutants, they are considered to have the most potential to replace ordinary Portland cement. However, similar to other inorganic materials, the GPs themselves have weak flexural and tensile strength and are sensitive to micro-cracks. Improving the toughness of GP materials can be achieved by adding an appropriate amount of fiber materials into the matrix. The use of discrete staple fibers shows great potential in improving the toughness of GPs. Sisal is a natural fiber that is reproducible and easy to obtain. Due to its good mechanical properties, low cost, and low carbon energy usage, sisal fiber (SF) is a GP composite reinforcement with potential development. In this paper, the research progress on the effect of SF on the properties of GP composites in recent decades is reviewed. It mainly includes the chemical composition and physical properties of SFs, the preparation technology of sisal-reinforced geopolymers (SFRGs), the microstructure analysis of the interface of SFs and the GP matrix, and the macroscopic mechanical properties of SFRGs. The properties of SFs make them have good bonding properties with the GP matrix. The addition of SFs can improve the flexural strength and tensile strength of GP composites, and SFRGs have good engineering application prospects. [ABSTRACT FROM AUTHOR]

The traditional preparation process of natural rubber latex requires tedious treatment of a variety of rubber additives. In this paper, a new process of wet mixed grinding was used to prepare a reinforced vulcanization mixture and a rapid vulcanization effect. The effect of different amounts of vulcanization mixtures on the mechanical properties of natural latex film was studied, and the pre-vulcanization process of latex and the vulcanization process of film were optimized. The results showed that with the increase in the amount of vulcanization mixture, the tensile strength increased from 5.96 MPa to 29.28 MPa, and the tear strength increased from 7.59 kN/m to 52.81 kN/m. When the vulcanization temperature of the latex film is heated from 80 °C to 100 °C, the vulcanization time is shortened by 5~6 times. The new vulcanization mixture prepared in this work has the characteristics of simple production and fast vulcanization speed, which provides a new solution for the development of the latex product industry. [ABSTRACT FROM AUTHOR]

Hydroxypropyl methylcellulose (HPMC)-coated papers without plasticizer and plasticized with polyols were prepared, and the effects of coating weight, different plasticizers (glycerol (GLY), sorbitol (SOR), and polyethylene glycol (PEG)), and plasticizer contents (20% to 50%) on the physical and mechanical properties of the resulting biopolymer-coated papers were studied. Coating weight was the most important factor affecting mechanical properties. Conversely, increasing coating weight led to a decrease in gloss and to an increase in tensile strength (TS), elongation at break (%E), and tearing resistance of coated papers. The application of unplasticized HPMC coatings (3 g/m²) on paper reduced water vapor permeability (WVP) and water absorption capacity by 25% as compared with uncoated paper. All plasticizers significantly (p < 0.05) increased WVP and Cobb60 values of the films. With the exception of PEG, no effect was found with plasticizers on TS and %E of coated papers compared with those without plasticizer. HPMC-coated papers with PEG as a plasticizer showed significantly lower TS and higher %E and tearing resistance than the other plasticized films (p < 0.05). HPMC coating improved tensile properties and tearing resistance of paper and could be regarded as a reinforcement layer. [ABSTRACT FROM AUTHOR]

The study and utilization of fully recycled aggregate concrete (FRAC), in which coarse and fine aggregates are completely replaced by recycled aggregates, are of great significance in improving the recycling rate of construction waste, reducing the carbon emission of construction materials, and alleviating the ecological degradation problems currently faced. In this paper, investigations were carried out to study the effects of steel fiber (0.5%, 1.0%, and 1.5%) and polypropylene fiber (0.9 kg/m3, 1.2 kg/m3 and 1.5 kg/m3) on the properties of FRAC, including compressive strength, splitting tensile strength, the splitting tensile load–displacement curve, the tensile toughness index, flexural strength, the load–deflection curve, and the flexural toughness index. The results show that the compressive strength, splitting tensile strength, and flexural strength of fiber-reinforced FRAC were remarkably enhanced compared with those of ordinary FRAC, and the maximum increase was 56.9%, 113.3%, and 217.0%, respectively. Overall, the enhancement effect of hybrid steel–polypropylene fiber is more significant than single-mixed fiber. Moreover, the enhancement of the crack resistance, tensile toughness, and flexural toughness obtained by adding steel fiber to the FRAC is more significant than that obtained by adding polypropylene fiber. Furthermore, adding polypropylene fiber alone and mixing it with steel fiber showed different FRAC splitting tensile and flexural properties. [ABSTRACT FROM AUTHOR]

Additive Manufacturing (AM) processes are known as revolutionary manufacturing processes that fabricate a part using a 3D model layer upon layer. These techniques gained more attention from various industries due to their advantages like low waste material. Also, these processes can produce any part with high degrees of complexity in a short period of time. The Fused Deposition Modeling (FDM) process is a material extrusion-based technique which works by extruding a fine molten polymeric filament through a heated nozzle on the heated platform named printer bed. In this method, some important manufacturing parameters play a crucial role in controlling the mechanical properties and quality of the final fabricated part. However, all printed specimens through the FDM process should be tested based on the standards under some critical circumstances. Thus, in the current research paper, five and three test speeds are considered in tensile and fracture testing procedures, respectively to evaluate how these speeds can affect the mechanical and mode I fracture properties. Also, as the FDM specimens present elastic–plastic behavior, the critical value of J-integral is assumed as a fracture assessment and calculated from the finite element analysis. Among the mechanical properties, ultimate tensile strength is affected significantly by the test speed. For instance, the ultimate tensile strength of FDM specimens is 39.02, 38.58, 42.33, 48.09, and 52.11 for test speeds of 2, 4, 6, 8, and 10 mm/min, respectively. But vice-versa results are detected for the mode I fracture behavior and corresponding values of J for the FDM-PLA specimens. Finally, experimental and numerical results together with comprehensive discussions about the considered speeds and obtained results are reported. [ABSTRACT FROM AUTHOR]

As a by-product of bamboo processing, bamboo powder is incinerated or buried due to its ineffective utilization, which contributes to pollution. The large amount of waste bamboo powder generated during the processing of bamboo products cannot be effectively utilized. Meanwhile, multiple recycling leads to the loss of fiber quality of corrugated cardboard (OCC) pulp, reducing the mechanical properties of paper. In an effort to obtain high value from waste bamboo powder, this study pulped it using the kraft process. Scanning electron microscope (SEM) observations showed that the surface of bamboo fiber had more cracks, which made bamboo fiber have better air permeability. The permeability of bamboo paper was 146% that of the OCC. X-ray diffraction (XRD) analysis showed that the crystallinity of bamboo pulp was 133% that of the OCC pulp. The results of physical testing of paper showed that the tensile strength of bamboo paper was 116% that of the OCC. The tear strength of bamboo paper was 61.7% that of the OCC, and the bursting strength of bamboo paper was 59.1% that of the OCC. Based on the above results, bamboo powder can be used as raw material for making OCC pulp. [ABSTRACT FROM AUTHOR]

Aramid fibers exhibit impressive mechanical properties, electrical insulation properties, and chemical stability. However, physical properties of the aramid paper are poor because of the chemical inertness and smooth surface of aramid fibers. This study reports a simple and efficient method for substantially improving the performance of the para-aramid/meta-aramid composite paper by introducing the N , N -dimethylacetamide (DMAc)/LiCl solution to induce partial dissolution or by adding the DMAc/LiCl/para-aramid solution to induce regeneration. Experimental results state that the tensile strength, specific strength, folding resistance, and interlayer bonding strength of the aramid paper are increased by 2.17, 2.13, 34.7, and 9.39 times, respectively, because of the dense and compact structure of the paper. Furthermore, the water resistance of the paper was also considerably improved. After immersing the paper samples in water for 24 h, their moisture absorption rate decreased to approximately 54% from approximately 143% for the original paper. Results indicate that partial dissolution/regeneration welding is a viable method for the efficient reinforcement of the aramid composite paper, providing additional possibilities for manufacturing the high-performance aramid paper-based materials. Unlabelled Image • The para-aramid/meta-aramid composite papers, exhibiting amazing mechanical strengths, were obtained. • The performance of the para-aramid/meta-aramid composite paper was improved by adding N , N -dimethylacetamide/LiCl solution. • The moisture absorption of aramid composite paper decreased from approximately 143% for the original paper to approximately 54%. [ABSTRACT FROM AUTHOR]

The effects of Mn addition on the room temperature tensile strength and deformation mechanisms of as-cast Mg-8Al-1Nd-1.5Gd-xMn alloys (x = 0, 0.3, 0.5, 1.0 wt.%) are investigated in this paper. The results indicate that the addition of Mn contributes to the precipitation of Al-Mn-RE intermetallics and the refinement of α-Mg matrices, thereby improving the tensile strength of the 1.0 Mn alloy at 190 MPa. The fracture mechanism of Mn-containing alloys transforms from a cleavage fracture to a ductile fracture as the Mn content increases from 0.3 to 1.0 wt.%. The presence of intermetallic particles in the dimples confirms the hindrance effect of Al10Mn2 (Nd,Gd) on dislocation slips. The novel technology of in-grain misorientation axes (IGMAs) is used to identify activated slip modes and deformation twins. It can be concluded that the activated pyramidal slip during tensile deformation significantly promotes the ductility of the 1.0 Mn alloy with an elongation rate of 9.8%. It is worth noting that reducing the coarse 10 1 ¯ 2 tensile twins and enhancing the proportion of 10 1 ¯ 1 compressive twins and 10 1 ¯ 1 - 10 1 ¯ 2 double twins contributes to maintaining the continuous plastic deformation of Mg alloy. [ABSTRACT FROM AUTHOR]

Inconel718 maintains excellent mechanical properties at high temperatures of 700 ℃ and has a wide range of applications in aerospace, high-performance turbines, and other fields. However, the use of improper laser process parameters makes the Inconel718 obtained by the directional energy deposition method have poor performance and defects, and there are currently fewer studies on the regulation of the mechanical properties of the preparation of Inconel718 by directed energy deposition. In this paper, the influencing regulation of laser process parameters of laser power, scanning speed, hatch spacing, layer thickness, and forming direction on the microstructure and mechanical properties of Inconel718 prepared by directional energy deposition is investigated by single-factor test method. The mechanical properties of Inconel718 obtained by directional energy deposition and forge are compared. The results show that, among the five laser process parameters, the laser power and forming direction have significant effect on the mechanical properties of Inconel718 obtained by directional energy deposition, while the scanning speed, scanning spacing, and layer thickness have less influence on its mechanical properties. Compared with Inconel718 prepared by ordinary forge, the tensile strength of Inconel718 obtained by directed energy deposition is reduced by 7.64%, the hardness is increased by 23.55%, the impact strength is reduced by 17.6%, and the plasticity is reduced obviously. Good mechanical properties can be reached from the Inconel718 obtained by the directional energy deposition method. [ABSTRACT FROM AUTHOR]

This research aims to determine the influence of water-soaking on polyester-based coated woven fabrics for ultimate tensile strength and elongation at break under uniaxial tensile tests. The paper begins with a short survey of literature concerning the investigation of the determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of a flat grip to establish the values of the ultimate tensile strength of groups of specimens treated with different moisture conditions. SEM fractography is performed to determine the cross-section structures of coated woven fabrics. The change in the mechanical properties caused by the influence of water immersion has not been noticed in the performed investigations. [ABSTRACT FROM AUTHOR]

In this paper, a disk laser welding was developed to join 3-mm thin-Sect. 30Cr3 ultra-high-strength steel which was widely used in aerospace. The microstructure and mechanical properties of welded joint were investigated in detail. The results indicated that the recommended laser linear energy range were between 150 and 165 J/mm to guarantee that the melting width was up to 1 mm as well as less oxidation, spatter, and depression on the weld. Meanwhile, for the as-welded (AW) condition, the base metal (BM) consisted of ferrite matrix with distributing small spherical carbides, also known as spherical pearlite. While, the fine grained region, coarse grained region, and weld metal were all composed of martensite. However, the partially transformed region mainly consisted martensite with a little of spherical pearlite. Meanwhile, the average grain sizes of weld metal, HAZ, and base metal were 1.3 μm, 1.5 μm, and 1.8 μm, respectively. However, for the post-weld heat treatment (PWHT) condition, the whole welded joint was all composed of tempered martensite, and the average grain size of welded joint was about 1.7 μm. The tensile strength of the welded joint was higher than that of the base metal both in the AW and PWHT condition as all the fracture with shrinkage occurred in the BM of the specimens. Additionally, the average yield strength of the AW and PWHT are about 600 MPa and 1700 MPa, respectively. [ABSTRACT FROM AUTHOR]

Previous studies have confirmed that for cemented tailings backfill, mechanical properties are improved through the addition of fiber. However, for fiber-reinforced cemented sulfur tailings backfill (FRCSTB), physical and flow properties are still unknown. In this paper, the changes in fluidity, splitting tensile strength (STS) and uniaxial compressive strength (UCS) of cemented sulfur tailings backfill (CSTB) are analyzed in detail. Secondly, regarding the addition of glass fiber and polypropylene fiber, the changes in the fluidity, STS and UCS of the CSTB, resulting from the fiber length, fiber content and method of fiber addition used, were analyzed. Moreover, the relationship between the UCS and fiber content is established. Finally, the mechanism behind the influence of fiber and sulfur content on the mechanical properties of CSTB is revealed. The results indicate that with the increase in sulfur content, the fluidity of the tailings slurry exhibits exponential growth. During the process of increasing sulfur content, the UCS and STS of CSTB initially increase and then decrease, reaching maximum values at 12% sulfur content. Similarly, at a fiber content of 0.6%, the UCS and 28d STS of CSTB reach their maximum values. In terms of enhancing the mechanical properties of CSTB, the effectiveness of glass fibers surpasses that of polypropylene fibers. In addition, regarding the improvement of the UCS of CSTB, the mixed addition of fibers is obviously worse than that of fiber alone. However, in terms of enhancing the STS of CSTB, the mixed addition of fibers outperforms the single addition of polypropylene fiber. From a microscopic perspective, polypropylene and glass fiber are able to form strong cohesion with the cement–tailings matrix and effectively prevent the formation and expansion of pores and cracks. [ABSTRACT FROM AUTHOR]

In this paper, the post-weld explosive hardening of a 5 mm AA7075-T651 plate welded via FSW was performed. To investigate the possibility of increasing FSW joint mechanical properties, the welded plate was explosively treated with four various explosive materials (ammonal, emulsion explosive, FOX-7, and PBX) in two different hardening systems. As part of the investigation, the observations of the surface and macrostructure of the treated plates were described. The obtained microhardness distribution allowed us to register the increase in hardness of the SZ up to 6%, but no increase in hardness of the LHZ was reported. In most cases, the influence of explosive treatment on the mechanical properties of the welded joint was disadvantageous as ultimate tensile strength and ductility were reduced. The only positive effect which was observed is the increase in the value of yield strength up to 27% corresponding to 77 MPa, achieved by explosive materials with detonation velocity below 3000 m/s. [ABSTRACT FROM AUTHOR]

This paper presents the results of physical modelling of the process of multi-pass rolling of a wire rod with controlled, multi-stage cooling. The main goal of this study was to verify the possibility of using a torsion plastometer, which allows conducting tests on multi-sequence torsion, tensile, compression and in the so-called complex strain state to physically replicate the actual technological process. The advantage of the research methodology proposed in this paper in relation to work published so far, is its ability to replicate the entire deformation cycle while precisely preserving the temperature of the deformed material during individual stages of the reproduced technological process and its ability to quickly and accurately determine selected mechanical properties during a static tensile test. Changes in the most important parameters of the process (strain, strain rate, temperature, and yield stress) were analyzed for each variant. After physical modelling, the material was subjected to metallographic and hardness tests. Then, on the basis of mathematical models and using measurements of the average grain size, chemical composition, and hardness, the yield strength, ultimate tensile strength, and plasticity reserve were determined. The scope of the tests also included determining selected mechanical properties during a static tensile test. The obtained results were verified by comparing to results obtained under industrial conditions. The best variant was a variant consisting of physically replicating the rolling process in a bar rolling mill as multi-sequence non-free torsion; the rolling process in an NTM block (no twist mill) as non-free continuous torsion, with the total strain equal to the actual strain occurring at this stage of the technological process; and the rolling process in an RSM block (reducing and sizing mill) as tension, while maintaining the total strain value in this block. The differences between the most important mechanical parameters determined during a static tensile test of a wire rod under industrial conditions and the material after physical modelling were 1.5% for yield strength, approximately 6.1% for ultimate tensile strength, and approximately 4.1% for the relative reduction of the area in the fracture and plasticity reserve. [ABSTRACT FROM AUTHOR]

Eichornia crassipes, ECs is an abundant source of natural fiber, environmentally friendly, and has a great potential to be used as filler in polymer composites. This literature review aims to provide the latest information on ECs synthesis, properties, and ECs-reinforced composites. Modification of the properties of ECs using alkaline chemicals is also discussed in detail through changes in physical, chemical, thermal, and mechanical properties, as well as fiber morphology. After being modified by alkaline chemistry, the fiber density of ECs can be reduced by around 20.69%, and the cellulose content of ECs can reach 90.24%. This literature review also discusses the physical, mechanical, and thermal properties of ECs-filled polymer composites from the results of the latest research and innovations. Polyester reinforced ECs with a length of 10 cm have modulus of elasticity and tensile strength of 11,023.33 N/m² and 648 N/m², respectively. Potential applications of ECs composites for product development; cost-effective and efficient replacement of inorganic fillers such as; gypsum, cooling pad, and pulp and paper. This study is expected to be a reference for the development of Eichornia crassipes fiber-filled composite technology for both industry and scientists. [ABSTRACT FROM AUTHOR]

The recycled paper and board industry needs to improve the quality of their products to meet customer demands. The refining process and strength additives are commonly used to increase mechanical properties. Interfiber bonding can also be improved using cellulose nanofibers (CNF). A circular economy approach in the industrial implementation of CNF can be addressed through the in situ production of CNF using side cellulose streams of the process as raw material, avoiding transportation costs and reducing industrial wastes. Furthermore, CNF fit for use can be produced for specific industrial applications.This study evaluates the feasibility of using two types of recycled fibers, simulating the broke streams of two paper machines producing newsprint and liner for cartonboard, to produce in situ CNF for direct application on the original pulps, old newsprint (ONP), and old corrugated container (OCC), and to reinforce the final products. The CNF were obtained by 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-mediated oxidation and homogenization at 600 bar. Handsheets were prepared with disintegrated recycled pulp and different amounts of CNF using a conventional three-component retention system. Results show that 3 wt.% of CNF produced with 10 mmol of NaClO per gram of dry pulp improve tensile index of ONP ~30%. For OCC, the same treatment and CNF dose increase tensile index above 60%. In both cases, CNF cause a deterioration of drainage, but this effect is effectively counteracted by optimising the retention system. [ABSTRACT FROM AUTHOR]

This research paper presents the fabrication of epoxy coatings along with the hybrid combination of SiO2 and ZrO2. The epoxy resin is incorporated with SiO2 as the primary pigment and ZrO2 as the synergist pigment. The study delves into the adhesion, barrier, and anti-corrosion properties of these coatings, enriched with silica and zirconium nanoparticles, and investigates their impact on the final properties of the epoxy coating. The epoxy resin, a Diglycidyl ether bisphenol-A (DGEBA) type, is cured with a polyamidoamine adduct-based curing agent. To evaluate the protective performance of silica SiO2 and zirconia ZrO2 nanoparticles in epoxy coatings, the coated samples were tested in a 3.5% NaCl solution. The experimental results clearly demonstrate a remarkable improvement in the ultimate tensile strength (UTS), yield strength (YS), and Elastic Modulus. In comparison to using SiO2 separately, the incorporation of both ZrO2 and SiO2 resulted in a substantial increase of 43.5% in UTS, 74.2% in YS, and 8.2% in Elastic Modulus. The corrosion test results revealed that the combination of DGEBA, SiO2, and ZrO2 significantly enhanced the anti-corrosion efficiency of the organic coatings. Both these pigments exhibited superior anti-corrosion effects and mechanical properties compared to conventional epoxy coatings, leading to a substantial increase in the anti-corrosion efficiency of the developed coating. This research focuses the potential of SiO2 and ZrO2 in hybrid combination for applications, where mechanical, corrosion and higher adhesion to the substrates are of prime importance. [ABSTRACT FROM AUTHOR]

Zinc (Zn)-based biodegradable materials show moderate degradation rates in comparison with other biodegradable materials (Fe and Mg). Biocompatibility and non-toxicity also make them a viable option for implant applications. Furthermore, Pure Zn has poor mechanical behavior, with a tensile strength of around 100–150 MPa and an elongation of 0.3–2%, which is far from reaching the strength required as an orthopedic implant material (tensile strength is more than 300 MPa, elongation more than 15%). Alloy and composite fabrication have proven to be excellent ways to improve the mechanical performance of Zn. Therefore, their alloys and composites have emerged as an innovative category of biodegradable materials. This paper summarizes the most important recent research results on the mechanical and biological characteristics of biodegradable Zn-based implants for orthopedic applications and the most commonly added components in Zn alloys and composites. [ABSTRACT FROM AUTHOR]

Strengthening the CoCrFeNi high entropy alloy with a face-center cubic structure has become a research prospect in the last decade. Alloying with double elements, Nb and Mo, is an effective method. In this paper, to further enhance the strength of the Nb and Mo contained high entropy alloy, CoCrFeNiNb0.2Mo0.2 was annealing treated at different temperatures for 24 h. As a result, a new kind of Cr2Nb type nano-scale precipitate with a hexagonal close-packed structure was formed, which is semi-coherent with the matrix. Moreover, by adjusting the annealing temperature, the precipitate was tailored with a considerable quantity and fine size. The best overall mechanical properties were achieved in the alloy annealed at 700 °C. The yield strength, ultimate tensile strength, and elongation are 727 MPa, 1.05 GPa, and 8.38%, respectively. The fracture mode of the annealed alloy is a mixture of cleavage and necking-featured ductile fracture. The approach employed in this study offers a theoretical foundation for enhancing the mechanical properties of face-centered cubic high entropy alloys via annealing treatment. [ABSTRACT FROM AUTHOR]

The effects of Al addition on the microstructure and mechanical properties of Mg-Zn-Sn-Mn-Ca alloys are studied in this paper. It was found that the Mg-6Sn-4Zn-1Mn-0.2Ca-xAl (ZTM641-0.2Ca-xAl, x = 0, 0.5, 1, 2 wt.%; hereafter, all compositions are in weight percent unless stated otherwise) alloys have α-Mg, Mg2Sn, Mg7Zn3, MgZn, α-Mn, CaMgSn, AlMn, Mg32(Al,Zn)49 phases. The grain is also refined when the Al element is added, and the angular-block AlMn phases are formed in the alloys. For the ZTM641-0.2Ca-xAl alloy, the higher Al content is beneficial to elongation, and the double-aged ZTM641-0.2Ca-2Al alloy has the highest elongation, which is 13.2%. The higher Al content enhances the high-temperature strength for the as-extruded ZTM641-0.2Ca alloy; overall, the as-extruded ZTM641-0.2Ca-2Al alloy has the best performance; that is, the tensile strength and yield strength of the ZTM641-0.2Ca-2Al alloy are 159 MPa and 132 MPa at 150 °C, and 103 MPa and 90 MPa at 200 °C, respectively. [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of semi-continuous casting Mg-Gd-Y-Zr magnesium alloys with different Zn contents were studied in this paper. The results showed that an increase in Zn content resulted in gradual refinement of the grains and a gradual increase in the volume fraction of the second phase. At a Zn content of 0.7 wt%, the microstructure was mainly composed of the α-Mg matrix and the Mg5(GdY) and long-period stacking order (LPSO) phases. An increase in the Zn content lowered the volume fraction of the Mg5(GdY) phase and increased the volume fraction of the LPSO phase. At a Zn content of 3.3 wt%, the microstructure was mainly composed of the α-Mg matrix and the LPSO phase. Among these alloys, the alloy without Zn addition showed an optimal ultimate tensile strength and yield strength of 229 MPa and 185 MPa, respectively, while the alloy with 3.3 wt% Zn showed an excellent elongation after fracture of 4.5%. The tensile fracture analysis indicated that the cracks of the alloy without Zn mainly originated at the trigeminal junction of the grain boundary, the cracks of the 0.7 wt% Zn and 1.5 wt% Zn alloy mainly originated at the interface of the Mg/lamellar LPSO phase, and the cracks of the 3.3 wt% Zn alloy mainly originated at the bulk LPSO phase of the grain boundary and then propagated along the bulk LPSO phase. [ABSTRACT FROM AUTHOR]

WIt has great environmental potential to replace natural aggregates by recycled brick aggregates. To investigate the deterioration mechanism of recycled brick aggregate concrete, this paper designed eight groups of recycled brick aggregate sub-lightweight concrete with different water-cement ratios, maximum aggregate sizes and coarse aggregate type ratios, and carried out mechanical property test to analyze the aggregate interface characteristics and the damage mechanism of recycled brick aggregate concrete. The results show that the increase of replacement ratio and water-cement ratio leads to a significant decrease of compressive strength and splitting tensile strength of concrete, and the influence of the maximum aggregate size on strength is small. Unlike the recycled concrete aggregate - mortar interface, the microstructure of recycled brick aggregate - mortar interface is dense and the interface performance is enhanced. Recycled brick aggregate concrete is in non-interface damage mode, and the strength of brick aggregate is the main influence to determine the mechanical properties of concrete factor. [ABSTRACT FROM AUTHOR]

The aim of this paper was to analyze the impact of varying zirconium addition on selected properties of AlSi5Cu2Mg alloy. The results of this research showed that zirconium addition in the range of 0.05 to 0.20 wt. % caused a decrease in ultimate tensile strength and yield strength of the experimental alloys after T7 heat treatment, probably due to the formation of primary Al3Zr intermetallic phases. These phases were observed as an individual plates or as a formation of two crossed plate-like phases. Potentiodynamic polarization tests in 3.5% NaCl solution revealed that addition of Zr had a positive effect on thermodynamic corrosion stability of the AlSi5Cu2Mg alloy due to shift of the corrosion potential to a more positive values for all as-cast samples. Addition of Zr in the as-cast alloys improved corrosion kinetics by lowering of corrosion current density. [ABSTRACT FROM AUTHOR]

The paper shows the degradation process of the modern austenitic Super 304H (X10CrNiCuNb18-9-3) steel which was subjected to long-term ageing for up to 50 000 h at 650 and 700°C. The investigations include microstructure examination (SEM), identification and analysis of the precipitation process, and mechanical properties tests. The Super 304H steel has a structure characteristic of austenitic steels with visible annealing twins and single primary NbX precipitates. Long-term ageing in steel leads to numerous precipitation processes of M23C6, MX carbides, s phase, Z phase, and e-Cu phase. Precipitation processes lead to a decrease in plastic properties and impact energy as well as alloy over ageing. Yield strength and tensile strength values after 50 000 h of ageing were similar to those as delivered. The yield and tensile strength value strongly depend on the applied ageing temperature. [ABSTRACT FROM AUTHOR]

This paper focuses on the study of the structure and mechanical properties of CoCrCuxFeNi high-entropy alloys and their adhesion to single diamond crystals. CoCrCuxFeNi alloys were manufactured by the powder metallurgy route, specifically via mechanical alloying of elemental powders, followed by hot pressing. The addition of copper led to the formation of a dual-phase FCC + FCC2 structure. The CoCrCu0.5FeNi alloy exhibited the highest ultimate tensile strength (1080 MPa). Reductions in the ductility of the CoCrCuxFeNi HEAs and the tendency for brittle fracture behavior were observed at high copper concentrations. The equiatomic alloys CoCrFeNi and CoCrCuFeNi demonstrated high adhesion strength to single diamond crystals. The diamond surface at the fracture of the composites having the CoCrFeNi matrix had chromium-rich metal matrix regions, thus indicating that chromium carbide, responsible for adhesion, was formed at the composite–diamond interface. Copper-rich areas were detected on the diamond surface within the composites having the CoCrCuFeNi matrix due to the predominant precipitation of the FCC2 phase at the interfaces or the crack propagation along the FCC/FCC2 interface, resulting in the exposure of the Cu-rich FCC2 phase on the surface. [ABSTRACT FROM AUTHOR]

AlSi10Mg has a good forming ability and has been widely accepted as an optimal material for selective laser melting (SLM). However, the strength and elongation of unmodified AlSi10Mg are insufficient, which limits its application in the space industry. In this paper, yttrium oxide (Y2O3) nanoparticles modified AlSi10Mg composites that were manufactured using SLM. The effects of Y2O3 nanoparticles (0~2 wt.% addition) on the microstructure and mechanical properties of AlSi10Mg alloys were investigated. An ultimate tensile strength of 500.3 MPa, a yield strength of 322.3 MPa, an elongation of 9.7%, a good friction coefficient of 0.43, and a wear rate of (3.40 ± 0.09) ×10−4 mm3·N−1·m−1 were obtained with the addition of 0.5 wt.% Y2O3 nanoparticles, and all these parameters were higher than those of the SLMed AlSi10Mg alloy. The microhardness of the composite with 1.0 wt.% Y2O3 reached 145.6 HV0.1, which is an increase of approximately 22% compared to the unreinforced AlSi10Mg. The improvement of tensile properties can mainly be attributed to Orowan strengthening, fine grain strengthening, and load-bearing strengthening. The results show that adding an appropriate amount of Y2O3 nanoparticles can significantly improve the properties of the SLMed AlSi10Mg alloy. [ABSTRACT FROM AUTHOR]

The objective of this paper is to to ascertain the reliable mechanical properties of cold-formed Q345 steel at elevated temperatures while considerting the effects of tensile strain rate and specimen width. This paper presents an experimental study on the mechanical properties of cold-formed Q345 steel at temperatures ranging from 20°C to 800°C tested with two specimen widths and three tensile–strain rates, namely 0.06/min , 0.6/min , and 1.2/min. Tensile specimens were fabricated from a steel plate with a nominal thickness of 2.5 mm and tensile tests were carried out to determine the stress–strain relationship, yield strength, tensile strength, and elastic modulus. The test results showed that the tensile–strain rate has a maximum influence of 9% on yield and tensile strength at 600°C and the specimen width has a maximum influence of 14% on yield and tensile strength at 400°C. The maximum influence of the tensile–strain rate and specimen width on the elastic modulus is 18% and 12% respectively at 500°C. The necking phenomenon is less noticeable at temperatures below 300°C but is clearly observed at temperatures above 300°C. The comparison of the test results with predictions obtained from design standards (EC3, AISC, and AS4100) indicates a good agreement on the yield and tensile strength, but the magnitudes of elastic modulus obtained from the test are considerably higher than those obtained from the design standards. Based on averaged values of the test results associated with different tensile–strain rates and specimen widths, predictive equations were proposed to determine the mechanical properties of cold-formed Q345 steel at elevated temperatures. [ABSTRACT FROM AUTHOR]

The Markforged Metal X (MfMX) printing machine (Markforged Inc., Massachusetts, USA) is one of the latest introduced additive manufacturing (AM) devices. It is getting popular because of its safety, simplicity, and ability to utilize various types of powders/filaments for printing. Despite this, only a few papers have so far reported the various properties and performances of the components fabricated by the MfMX printer. In this study, the microstructure and mechanical properties of MfMX-fabricated 17-4 stainless steel (ss) in the as-printed and heat-treated conditions were investigated. XRD and microscopy analyses revealed a dominant martensitic microstructure with some retained austenite phase. The microstructure is generally characterized by patterned voids that were unfilled due to a lack of fusion between the adjacent filaments. Disregarding these defects (voids), the porosity of the dense region was less than 4%. Depending on the heat treatment conditions, the hardness and tensile strength were enhanced by 17–28% and 21–27%, respectively. However, the tensile strength analyzed in this work was low compared with some previous reports for L-PBF-fabricated 17-4 ss. In contrast, the hardness of the as-printed (331 ± 28 HV) and heat-treated samples under the H900 condition (417 ± 29 HV) were comparable with (and even better than) some reports in the literature, despite the low material density. The results generally indicated that the Markforged printer is a promising technology when the printing processes are fully developed and optimized. [ABSTRACT FROM AUTHOR]

The recycling industry has developed rapidly in recent years. Paper, plastic, glass, and metals are the most recycled materials. In this study, composite boards were produced using recycled polyethylene (R-PE) mixed with used Tetra Pak® boxes (TPBs) and pine wood flour (PWF) as fillers. The ratios of TPB to wood flour used in study were 0%, 10%, 20%, 30%, and 40%. Six test groups of composites were prepared. For each group, four composite boards of dimensions 4 × 180 × 220 mm³ were produced. Some of the mechanical properties of the produced boards, such as the flexural strength, flexural modulus, tensile strength, tensile modulus, elongation at break, and Shore D hardness, were determined. The data obtained showed that the flexural modulus, tensile modulus, and density increased with the wood flour content. However, the flexural strength, tensile strength, and elongation at break decreased as the wood flour content was increased. As a result, it can be said that TPBs could be used as a filler instead of wood flour in the production of wood-plastic composites. [ABSTRACT FROM AUTHOR]

Titanium alloy extruded profiles with complex cross-section are usually used to manufacture special-shaped structural parts in the aviation industry. In this paper, a Ti-6Al-4 V profile with asymmetric Y shape was manufactured by a direct extrusion process. A comparative study was conducted at the different lubrication conditions, in which the different process deformation mechanisms, resulting microstructures, and mechanical properties of profiles have been investigated by finite element simulation and a series of experiments, i.e., scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). It was revealed that the metal flow is blocked at the narrow die orifice due to the deterioration of lubrication, resulting in the continuous shrinkage defect. The metal deformation coordination mechanism becomes gradually significant due to poor friction contact, which promotes the internal stress in the cross-sectional center to transfer outward to balance the friction at the edge of the orifice, resulting in the reduction of the effective strain in the center. The heat generated by friction weakens the heat exchange behavior between the metal and the die, which helps the profile retain a more uniform temperature field. In the sectional center of the profiles made from the two different lubrications, extrusion with good lubrication results in greater grain/colony refinement due to greater effective strains, and a slightly greater dislocation density was found due to the uniform deformation. The tensile tests revealed that compared with poor lubrication, due to the improvement of Hall–Petch strengthening and dislocation strengthening in the cross-sectional center with good lubrication, the variation range of yield strength and tensile strength is reduced to 11 MPa and 7 MPa, respectively, and the variation range of microhardness is reduced to 44 HV and 32 HV, respectively. The improvement of lubrication not only helps to reduce forming defects but also can obtain uniform mechanical properties. [ABSTRACT FROM AUTHOR]

Multilayered materials are widely studied due to their special structures and great properties, such as their mechanical ones. In this paper a novel and effective technique, a quadruple-layering approach, was used to fabricate multilayered materials. This approach increases the number of layers rapidly via simple operations. Materials with 4, 16, and 64 layers with alternating layers of polypropylene and nanocomposites were fabricated using this approach, and their film morphology and mechanical properties were studied. The influence of the number of layers on the mechanical properties of the materials and the relationship between the mechanical properties of each material were investigated. The results illustrated that the tensile modulus and strength were enhanced and elongation at the break increased when the layer numbers of the multilayered materials increased. However, this approach has a defect in that as the layer number increases, the layer thickness was not uniform, thus restricting the improvement of properties. This may need to be further studied in future work. [ABSTRACT FROM AUTHOR]

The high entropy alloys (HEAs) are widely used in high temperature service environment (such as aviation engine blades) with bright application potential in additive manufacturing. Laser powder bed fusion (LPBF) is technology currently offers the best reproducibility and dimensional accuracy for part production. The unique atomic lattice structure of HEA makes its plastic deformation mechanism different from that of traditional dilution alloy, resulting in the strengthening effect of face-centered cubic high-entropy alloy different from that of traditional metal alloy materials. In this paper, Ni 8 Cr 4 Co 4 Fe 6 W 2 was designed by means of composition control. Its spherical powders with uniform composition were successfully prepared by high temperature remelting spheroidization (PHTR) method, compared with gas atomization (GA) method. The strain rate sensitivity m values of GA-Selective Laser Melting and PHTR-Selective Laser Melting samples were 0.030 and 0.027, respectively. The hardness of Ni 8 Cr 4 Co 4 Fe 6 W 2 high-entropy alloy showed a trend of continuous increase with the decrease of grain size, while the elastic modulus didn't change much (PHTR-SLM is 193 Gpa and GA-SLM is 189 Gpa). The simulated value of the contact stress decreased by 23 % compared with the theoretical value. The contact radius increased with the increase of plastic deformation in addition to the reduction of contact pressure. The printing sample value of the elongation, yield strength (YS) and Ultimate Tensile Strength (UTS) on PHTR-SLM has increased by 39.6 %, 33.7 % and 25.9 %, respectively in additive manufacturing, compared to GA-SLM. The ability to produce refractory HEAs through PHTR method will make it possible to manufacture complex geometry shapes at a reasonable cost. ● The alloy specimens have extremely small size and obtain single FCC solid solution by SLM process. ● The strain rate sensitivity index m of PHTR-SLM sample is 0.027. ● Ni 8 Cr 4 Co 4 Fe 6 W 2 alloy shows high strength and ductility in additive manufacturing. ● The simulated value of the contact stress decreases by 23% compared with the theoretical value. [ABSTRACT FROM AUTHOR]

Ceramic matrix composites have garnered significant attention in aerospace and other fields due to their outstanding properties. However, as a common and critical defect, density defect often results in non-uniform matrix distribution and internal pore formation, posing a substantial risk to component safety. This paper presents a novel method aimed at deliberately inducing varying degrees of density defects in SiC f /SiC. The feasibility of this method is validated using infrared thermography and computed tomography. As density defects aggravate, the porosity of the sample's defective region gradually increases, with both the number of micropores and the dimensions of larger pores expanding. This trend underscores the decreased compactness of the SiC matrix. Additionally, there is an initial decline in tensile strength followed by stabilization, while the tensile elastic modulus exhibits a continued decrease. The retention rates of the minimum tensile strength and tensile elastic modulus are 83.89 % and 64.77 %, respectively, compared to those of the defect-free samples. In terms of compressive properties, both compressive strength and compressive elastic modulus exhibit progressive decreases, culminating in final retention rates of 76.54 % and 72.02 %, respectively. Density defects reduce the matrix cracking stress and introduce new defects such as delamination, thereby altering the material's damage mechanism. This study provides innovative perspectives for risk assessment and lifespan prediction of density defects, especially concerning more complex components like turbine blades. • Artificial defects containing locally varying density values are controlled in SiC f /SiC for the first time. • Tensile strength demonstrates higher tolerance to more severe density defects than compressive strength. • Evaluating density defects by correlating pore geometry with material mechanical properties offers a novel approach. [ABSTRACT FROM AUTHOR]

Heat treatment is necessary for GW63K (Mg-6Gd-3Y-0.5Zr, wt%) alloy fabricated by wire are additive manufacturing (WAAM) to improve the mechanical properties before final applications. Considering the unique solidification process and microstructure of WAAMed GW63K alloys, the heat treatment parameters must be different from the cast or forged ones. Thus, the present paper investigated the influence of solution temperature and time on the microstructure and mechanical properties of WAAMed GW63K, as well as the aging temperature and time. It was found that the as-deposited alloy exhibited fine equiaxed α-Mg grains with an average size of 13 μm and few eutectic phase Mg 24 (Gd, Y) 5 around the grains. The proper temperature of solution treatment was 480℃ and the proper time was 0.5 h, lower and shorter than cast ones. After solution treatment, the average size of α-Mg grains almost remained the same and nearly all of the eutectic phase dissolved. To exert precipitation strengthening to a larger extent, we conduct aging treatment at 175°C, 200°C, and 225°C and draw their age-hardening curves. Besides, a superior strength /ductility trade-off was obtained peak aging at 200°C for 80 h, with the ultimate tensile strength of 337±8 MPa, yielding strength of 231±2 MPa, and elongation of 8.9±1.0%. This outstanding strength can be accounted for by the refinement strengthening of fine microstructure inherited from as-deposited GW63K alloy and precipitation strengthening from dense β′ precipitates with a remarkable plate aspect ratio. Besides, suitable β′ precipitates could support a favorable work hardening effect and compatible deformation capability. • The Mg-6Gd-3Y-0.5Zr alloy with low rare earth content fabricated by WAAM has obtained fine microstructure. • The refinement of microstructure would be retained under an optimal solution treatment (480°C×0.5 h). • A superior strength /ductility trade-off with UTS of 337±8 MPa, YS of 231±2 MPa and EL of 8.9±2.0% was obtained. [ABSTRACT FROM AUTHOR]

The spread of 3D printing in many different fields has become eminent. This paper aims to improve the mechanical properties of parts printed by fused deposition modeling technique. Acrylonitrile butadiene styrene (ABS) specimens are printed with custom printing parameters. These parameters give a tensile strength that is 86% of the injection- molded ABS strength, and give one of the best recorded results for 100% infill printed ABS tensile specimens. Furthermore, a post filling technique has been studied. Specimens are printed with inner voids and different densities using slicing software. Void shape is precisely selected to conform to the filling process. High-strength, low-cost thermoset resin is injected through specimens to fill those voids. A tensile test has been performed after the full curing of the resin. A morphology analysis is done. Using this technique strength to printed weight ratio is improved by 151% and the cost is reduced by 51%. [ABSTRACT FROM AUTHOR]

In this paper, the tensile behavior of industrial polypropylene triaxial geogrid with different pre-punched hole diameters was studied by experiment and numerical analysis. The industrial polypropylene sheets with different diameters of circular holes were stretched at elevated temperature and then the tensile properties of triaxial geogrids at room temperature were evaluated. It was found that the pre-punched hole diameter of triaxial geogrid had a very close relationship with the mechanical properties. With the increase of the pre-punched hole diameter, the tensile strength of triaxial geogrid shows a trend of first increasing and then decreasing. Combined with numerical simulation, the optimal pre-punched hole diameter can be accurately obtained, and the distribution law of the width, thickness, stress, and strain of triaxial geogrid can be obtained. Under the condition of a stretching ratio of 3 and node spacing of 3 mm, it was found that the mechanical properties of industrial polypropylene triaxial geogrid was the best when the pre-punched hole diameter was 2.6 mm. [ABSTRACT FROM AUTHOR]

In the blending process of the composites, the clustering of MWCNTs under high concentration leads to poor dispersion and difficult complexing with luminescent elements. Cyanate ester resins (CERs) have a brittle network structure when cured caused by a conjugation effect that forms a strong emission peak in the ultraviolet-visible region and quenches the luminescent elements of the fluorescent nanofillers. In this paper, by anchoring of the Eu complex (Eu(TTA)3Phen, ETP) on a surface of longitudinal split unzipped carbon nanotubes (uMWCNTs); fluorescent nanoparticles were prepared as ETP anchor unzipper carbon nanotubes (ETP-uCNTs). Dicyanate ester of bisphenol E (CER-E monomer) is cured to polycyanurate at a lower temperature to achieve a high conversion, promoting a uniform blend with ETP-uCNTs, providing the fluorescence environment with high color purity. Studies show the ETP-uCNTs solve the agglomeration of MWCNTs and improve the interface binding ability. Compared with the pure CER-E, the tensile strength, bending strength and impact strength of CER-E/0.8 wt.% ETP-uCNT hybrid nanocomposites are increased by 94.6%, 92.8% and 101.1%, respectively. The carbon residue rate of CER-E/ETP-uCNTs is up to 47.14% at 800 °C, the temperature of the maximum reaction rate decreases by 67.81 °C, and the partial absorption of ultraviolet light is realized between 200 and 400 nm. [ABSTRACT FROM AUTHOR]

The temperature gradient and mismatching between the thermal expansion of the core and flange readily lead to cracks and discharges on the core surface of the dry-type valve-side bushing, which severely impact the safety of power systems. It is vital to clarify the cracking risk of bushing cores under temperature gradients and establish corresponding control methods. The mechanical properties of epoxy resin impregnated paper (ERIP) material were measured in this study at different temperatures, and a thermal–mechanical coupling simulation model was established. The thermal and stress distributions of the core were obtained and the cracking risk was defined accordingly. The crack development mode was explored as it relates to the phase-field mode. Various elastic cushion materials affecting the stress distribution of the core were investigated. The results show that the mechanical properties of the ERIP material decrease rapidly as the temperature increases. When under severe working conditions, the maximum first principal stress of the core may be significantly higher than the tensile strength of the ERIP material resulting in significant axial cracks. Adding an elastic cushion layer made of polyurethane rubber can effectively relax the interface stress and reduce the cracking risk. [ABSTRACT FROM AUTHOR]

Due to the complexity of the marine environment, in deep-sea drilling, all kinds of strings are corroded by different deep-sea conditions for a long time, accompanied by high temperature and high pressure, which lead to the continuous change of mechanical properties of materials. In order to solve the problem that the material mechanical parameters cannot be accurately described in the performance analysis of the casing, deep-sea simulated corrosion and material damage experiments of P110 material were carried out in this paper. Mass loss and tensile experiments on corrosion-damaged test pieces were conducted under different corrosion experimental periods. The changes in mechanical properties of the material were analyzed. Equations of the variation of the equivalent yield strength and the equivalent tensile strength were obtained. The results show that the equivalent yield strength and the equivalent tensile strength decrease with the increase of the weight loss rate. Based on the experimental results and finite element analysis, a method for establishing the material corrosion model was proposed in this paper. The deep-sea drilling corrosion performance model of P110 material was established, which greatly reduced the error caused by the material uniformity assumption in finite element analysis. This paper provides a theoretical basis for the analysis of reliability and life of P110 materials in wells. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEAs) show great promise for various applications in many fields. However, it still remains a challenge to obtain the ideal match of the tensile strength and the ductility. In this paper, Al0.5FeCoCrNi walls were fabricated through laser melting deposition (LMD) technology with laser power ranging from 1000 W to 1800 W. Along with the increase in laser power, the average size of the Al0.5FeCoCrNi walls increased from 14.31 μm to 34.88 μm, and the B2 phase decreased from 16.5% to 2.1%. Notably, the ultimate tensile strength and the ductility of the 1000 W bottom wall were 737 MPa and 24.6%, respectively, while those of 1800 W top wall were 641 MPa and 27.6%, respectively, demonstrating that the tensile strength of the walls decreased and the ductility increased with the increase in laser power. Furthermore, quantitative calculation revealed that grain boundary strengthening and dislocation strengthening were the two major forms of strengthening compared to the others. This study concluded that the mechanical properties of HEAs could be regulated by laser power, enabling broader applications in industry with favorable tensile strength or ductility. [ABSTRACT FROM AUTHOR]

AISI 316L stainless steel (SS) is one of the extensively used biomaterials to produce implants and medical devices. It provides a low-cost solution with ample mechanical properties, corrosion resistance, and biocompatibility compared to its counterpart materials. However, the implants made of this material are subjected to a short life span in human physiological conditions leading to the leaching of metal ions, thus limiting its use as a biomaterial. In this research, the addition of boron, titanium, and niobium with varying concentrations in the SS matrix has been explored. This paper explores the impact of material composition on modified SS alloy's physical and mechanical properties. The study's outcomes specify that the microhardness increases for all the alloy compositions, with a maximum increase of 64.68% for the 2 wt.% niobium added SS alloy. On the other hand, the tensile strength decreased to 297.40 MPa for the alloy containing 0.25 wt.% boron and 2 wt.% titanium additions compared to a tensile strength of 572.50 MPa for pure SS. The compression strength increased from 776 MPa for pure SS to 1408 MPa for the alloy containing niobium and titanium additions in equal concentrations. [ABSTRACT FROM AUTHOR]

In order to obtain high-performance aluminum alloy parts fabricated by selective laser melting, this paper investigates the relationship between the process parameters and microstructure properties of AlSi10Mg. The appropriate process parameters are obtained: the layer thickness is 0.03 mm, the laser power is 370 W, the scanning speed is 1454 mm/s, and the hatch spacing is 0.16 mm. With these process parameters, the ultimate tensile strength of the as-printed status is 500.7 ± 0.8 MPa, the yield strength is 311.5 ± 5.9 MPa, the elongation is 7.7 ± 0.5%, and the relative density is 99.94%. After annealing treatment at 275 °C for 2 h, the ultimate tensile strength is 310.8 ± 1.3 MPa, the yield strength is 198.0 ± 2.0 MPa, and the elongation is 13.7 ± 0.6%. The mechanical properties are mainly due to the high relative density, supersaturate solid solution, and fine dispersed Si. The supersaturate solid solution and nano-sized Si formed by the high cooling rate of SLM. After annealing treatment, the Si have been granulated and grown significantly. The ultimate tensile strength and yield strength are reduced, and the elongation is significantly improved. [ABSTRACT FROM AUTHOR]

To satisfy the increasing demand of energy efficient buildings, AAC manufacturers are nowadays encouraged to produce blocks with ever lower densities. However, a compromise between energy-saving requirements and mechanical performances is needed to ensure structural safety, as well as an adequate structural durability. This paper reports a comprehensive experimental study on AAC mechanical properties (compressive and tensile strengths, as well as fracture energy), and on their dependency from material density and moisture content. The collected data are compared with some well-known analytical relations taken from the literature, which are often used for the calibration of mechanical parameters required for mathematical and/or finite element modelling of AAC load-bearing masonry, as well as of AAC masonry-infilled framed structures. These comparisons highlight some critical issues in the formulation of analytical relations having a general applicability; however, it was found that RILEM suggestions are appropriate for the considered AAC productions, at least for densities greater than 400 kg/m³. [ABSTRACT FROM AUTHOR]

In this paper, high-density polyethylene (HDPE) composite pipes, reinforced with glass fibers (GF) and carbon nanotubes (CNTs), are manufactured using a novel extruder and multiple molten reprocessing cycles in a screw cylinder barrel. Moreover, the study investigates the tensile strength of the junction of these composite pipes. The results indicate that the Young's modulus and the ultimate tensile strength of the fabricated nanocomposite pipes increase by 150 and 163 %, compared to the conventional polyethylene pipes, respectively, using 2 wt% carbon nanotubes and two reprocessing iterations in the cylinder barrel. The effects of adding carbon nanotubes to HDPE and the number of reprocessing cycles on the fracture mechanism of the nanocomposite pipes have been explored based on SEM images and DSC testing. The pipes are joined using the two most common available methods; namely, butt fusion and electrofusion, and their respective tensile strengths are compared. The results demonstrate an 82 % and a 37 % decrease in the tensile strength for the welded pipes, compared to the non-welded pipes, using butt fusion and electrofusion, respectively. However, the tensile strength in the welding of the GFRP nanocomposite pipes can be enhanced by increasing the interconnection between the fibers at the junction. Nevertheless, butt fusion is not recommended for joining FRP composite pipes, while electrofusion can be utilized with some modifications. [ABSTRACT FROM AUTHOR]