Search

Wax printing is the most widely used method for fabricating microfluidic paper-based analytical devices (μPADs), but it still suffers from disadvantages like discontinuation of wax printers and need for additional equipment for heating treatment. To address these issues, this work initially describes a new class of wax printing approach for high-precision, batch fabrication of μPADs using a household 3D printer. It only involves a one patterning step of printing polyethylene wax into rice paper body. Under optimized parameters, a fabrication resolution, namely the minimum hydrophilic channel width, down to ~189 ± 30 μm could be achieved. In addition, the analytical applicability of such polyethylene wax-patterned μPADs was demonstrated well with enhanced colorimetric detection of dopamine as a model analyte by combining metal-organic framework (MOF) based nanoenzymes (ZIF-67) with a smartphone (for portable quantitative readout). The developed nanosensor could linearly detect dopamine over a concentration range from 10 to 1000 μM, with a detection limit of ca. 2.75 μM (3σ). The recovery results for analyzing several real samples (i.e., pig feed, chicken feed, pork and human serum) were between 91.82 and 102.79%, further validating its good detection accuracy for potential practical applications in food safety and medical diagnosis. [ABSTRACT FROM AUTHOR]

Oxide dispersion strengthened (ODS) alloys, due to their high irradiation resistance and good mechanical properties at high temperatures, are promising for applications in Generation IV reactors, especially GFR, and fusion installations. However, the biggest challenge in applying ODS materials is related to fabrication techniques. This paper aims to evaluate powder metallurgy processing and the effect of small additions of oxide- and carbide-forming elements on the microstructure and mechanical properties of Fe–Cr–Al-based ODS alloys. The series of ODS alloys with Y2O3 and different additions of Ti and V was prepared by mechanical alloying (MA) and consolidated by spark plasma sintering (SPS), which is less often employed to fabricate ODS alloys than hot extrusion or hot isostatic pressing. The investigations were performed on MAed powders, bulk-sintered samples, and samples after homogenization annealing. The MAed powders reveal two body-centered cubic (bcc) alloyed phases with close lattice parameters. The sintered samples show a single bcc phase (a = 2.88–2.89 Å) matrix and a high-volume fraction of homogenously distributed nanometric oxide precipitates. The addition of vanadium and titanium leads to the formation of vanadium- and titanium-rich nanometric oxides and carbides. The bulk samples show fine grain and stable microstructure with an average grain size slightly below 1 µm. Moreover, after homogenization annealing and air cooling, the relative density slightly increases. Hardness after heat treatment is relatively stable, which was confirmed by nanoindentation and Vickers microhardness results. These experimental findings promise to develop Fe–Cr–Al-based ODS materials tailored for operation under harsh conditions in nuclear reactors. [ABSTRACT FROM AUTHOR]

This paper utilizes the plasma arc as the heat source to successfully fabricate well-formed thin-walled parts using combined cable wire duplex stainless steel 2209. Microstructure of parts exhibited the favorable two-phase ratio and the absence of σ-phase. It was found that appropriate heat input (1.68 kJ/cm) and cooling rate (5 °C/s) can effectively avoid the precipitation of σ-phase. Furthermore, the properties of the as-deposited samples were comparable to those of the samples heat-treated at 1300 °C, proving that no subsequent heat treatment was required for 2209 stainless steel fabricated by plasma arc additive manufacture. The samples showed excellent properties, in which the ultimate tensile strength and yield strength were improved by about 7% and 24% compared with GB/T4237-2015. The impact toughness meets the requirements of EN10028-7-2016, which is about 35% higher than that of the cold metal transfer samples, and the corrosion resistance is comparable to that of hot rolled 2205. [ABSTRACT FROM AUTHOR]

This paper addresses a preliminary study on the emission control of pollutants from an industrial furnace. The stack sampling technique was implemented in this study, and the quantity of pollutants released from the furnace smoke was monitored. The transverse points required to collect the data were selected based on the upstream and downstream disturbances. At first, the investigation was made with the furnace oil. A 15.28% and 5.1% of CO2 and O2 were observed in the flue gas from of regular furnace oil. Hence, by considering the emission level observed, the analysis was repeated with the low sulphur-low stack and the coal tar fuel. The emission of SO2 and N2 was reduced with coal-tar fuel compared with the regular furnace fuel. Thus, the proposed operational adjustment attenuates the pollutant emission, which also helps to reduce the unfavorable impact on the environment. In the future, the authors intend to include a design change in the furnace burner, which would help to increase fuel efficiency and reduce pollution. [ABSTRACT FROM AUTHOR]

Many different processes have been developed to grow graphene film to protect metals. These processes are primarily based on chemical vapour deposition and are challenging to scale. In this paper, we have attempted to grow the reduced graphene oxide (rGO)-like film using the natural resin 'shellac' as a precursor through the simple process of dip coating of shellac varnish and annealing of coated substrates in a reducing atmosphere. X-ray diffraction (XRD) analysis and Raman spectroscopy were used to establish the rGO phases grown in the coating. The corrosion studies of rGO films grown on cold-rolled interstitial-free steel are investigated with different loadings of shellac in the varnish solution and subsequent heat treatments. Scanning electron probe micro-analysis was done to do elemental analysis, and potentiometric studies were done to investigate the corrosion behaviour of the coatings. The structure–property correlation of the film has established the corrosion mechanism using different microscopy techniques. [ABSTRACT FROM AUTHOR]

Screen printing enables the production of very thin magnetic sheet laminations in near net shape geometry. This minimizes material waste in production and simultaneously reduces losses during machine operation and in-creases geometric design freedom. The subsequent sintering process step is particularly relevant, since the geometrical and magnetic properties are defined, and relevant process costs are caused by the heat treatment. This paper presents the requirements of the debinding and sintering process for magnetic sheets and identifies relevant influencing factors to achieve defined product specifications in multiple iterations, using design of experiments. It focuses on the influencing factors furnace atmosphere, sintering temperature, holding time and stacking height and their impact on the magnetic and geometric properties of sintered magnetic sheets. [ABSTRACT FROM AUTHOR]

In this work, the influence of Mo in the CoNiFeMn system during heat treatment after prior hot and cold rolling was investigated. At present, relatively few studies on static recrystallization and grain growth kinetics in high entropy alloys are available. This paper focuses on static recrystallization and grain growth kinetics as well as the influence of molybdenum on these phenomena. This work compares two alloys, CoNiFeMn and (CoNiFeMn)95Mo5, in relation to the formations of the brittle µ phase at room- and high-temperature plastic deformation regimes due to its negative affect on material ductility. Microstructures were characterized by energy dispersive X-ray spectroscopy analysis and by scanning electron microscopy, whereas the mechanical properties were assessed by tensile testing. The effect of recrystallization and grain growth behaviours on the microstructural evolution and the final mechanical properties was assessed. It was found that Mo addition into the CoNiFeMn system has a strong effect on both the static recrystallization and grain growth kinetics as well as the final mechanical properties. [ABSTRACT FROM AUTHOR]

The failure of the circulation pump in a sulfur recovery unit occurred after 11 years of operation, during which it was exposed to the weak acid process stream. The A494-CW6M impeller of the pump was found to be completely shattered, leading to the failure. Despite the long operating period, the failure appearance was unusual, and further investigation was needed to understand the cause of the failure. To this end, the detailed metallurgical characterization was performed using the electron microscope and commercially available thermodynamic software. The experimental results showed that the leached regions exhibited more than 50% of the impeller thickness, and those were matched with topological closed phases (M6C, Sigma, P phase), which commonly had low Cr (10 ~ 11 wt.%) and high Mo (56 ~ 58 wt.%) composition. The failure was attributed to the weak corrosion resistance of the low Cr phases when exposed to oxidizing weak acid streams. In addition, thermodynamic phase calculation showed that a large amount of TCPs precipitation was likely due to the malpractice of the heat treatment process. The detailed failure analysis result will be discussed in the present paper. [ABSTRACT FROM AUTHOR]

The chemical compositions optimization, microstructure and mechanical properties of high-solid-fraction (40–60%) semi-solid A380 alloy were investigated in this paper. The effects of content of Si and Cu on preparation temperature of the semi-solid slurry were researched by thermodynamic calculation and differential scanning calorimetry. Based on commercial A380 alloy, the compositions (Si and Cu) were optimized for the preparation of high-solid-fraction slurry with swirled enthalpy equilibrium device. The results indicated that as the content of Si and Cu decreased, the temperature range of process window widened, which is beneficial for the slurry preparation and following semi-solid rheo-diecasting process. With the optimized A380 alloy, bracket casting for truck was produced by high-solid-fraction semi-solid diecasting. The microstructure and mechanical properties of tensile samples took from the real castings were quantitatively characterized. The solid fraction of 58% and average grain diameter about 60 μm were achieved with sphere-like primary Al (α-Al) phase in casting parts. After T6 heat treatment, the ultimate tensile strength, yield strength and microhardness of real casting parts were 381.9 MPa, 332.6 MPa and 133.6 HV, which were increased by 61.9%, 181.3% and 69.7% compared with that of as-cast state, respectively. High solid fraction enables the AlSi8Cu3 perform complete T6 heat treatment and low gas porosity, so the optimized A380 alloy exhibits higher strength than that of low-solid-fraction semi-solid rheo-diecasting and the presence of the high-density precipitates (θ′) provided better reinforcement effect. The micro-mechanism of fracture reveals that the as-cast samples were quasi-cleavage, while the T6 heat-treated samples were dimple and quasi-cleavage. [ABSTRACT FROM AUTHOR]

Thermal–mechanical damage is an important problem threatening the safety of deep rock engineering. In this paper, the effects of coupling damage on the deformation and failure characteristics of rock mass were studied via cyclic loading damage, thermal damage and uniaxial compression acoustic emission (AE) tests, and the microscopic fracture process of the damaged rock mass was numerically simulated. Results showed that during heat treatment, the colour of the sample changed significantly, the mass, the P-wave velocity and the number of mineral species decreased. The peak strength and elastic modulus reach their maximum values at 600 °C and 300 °C, respectively, exhibiting a trend of initial increase and subsequent decrease. The rapid growth period of AE activity increased noticeably with increasing temperature, and the effect of energy accumulation became more significant at higher peak strengths. The failure mode was influenced primarily by the cyclic loading amplitude. In addition, an increase in the stress or temperature after crack initiation leads to a sharp increase in the damage within the rock. Temperature had a more significant effect on the generation of damage than stress. Stress-induced microcracks were concentrated in the weakly bonded particles, whilst temperature-induced microcracks were concentrated in the strongly bonded particles. Highlights: Temperature had a significant effect on the mineral composition of rock mass. The rapid growth period of AE activity was prolonged with the temperature increase. The failure mode of rock mass was mainly influenced by cyclic loading amplitude. Temperature-induced microcracks were concentrated in strongly bonded particles. [ABSTRACT FROM AUTHOR]

The mechanisms of microstructure transformation and mechanical anisotropy of laser-MIG hybrid additive manufacturing TC11 titanium alloy after solution aging treatment are investigated. In this paper, different solution temperatures and cooling modes are applied to tailor the microstructure and improve high-temperature properties and anisotropy. The result shows the microstructure of the samples in the as-deposited state is dominated by a widmanstatten structure composed of lamellar α clusters. Following solution aging treatment, a large area of basket-weave structure is obtained in the samples. A major influence of spheroidization of lamellar α clusters and dynamic recrystallization on mechanical anisotropy is revealed. The heat-treated samples exhibit more superior combined strength, elongation, impact toughness. The hardness difference between the layers and mechanical anisotropy decreases. During high-temperature tensile tests, the tensile strength increases with rising solution temperature; while, the elongation shows the opposite trend. The tensile fracture exhibits abundant uniform equiaxed dimples, and the fracture mode changes from intergranular fracture to transgranular fracture. Solution treatment at 990 °C for 2 h followed by air cooling is considered to be the optimal heat treatment process. Consequently, it results in a high tensile strength of 811 MPa and an excellent impact toughness of 50 J, representing improvements of 16.08% and 71.08%. [ABSTRACT FROM AUTHOR]

Electron powder bed fusion (EPBF), as one of the common additive manufacturing techniques, has received increasing attention. EPBF-processed Ti-6Al-4V is widely used in biomedical and aerospace industries. However, titanium alloys prepared by EPBF have large pores and poor corrosion resistance. Heat treatment is a simple and non-polluting way to improve material properties. However, the effect of heat treatment on the corrosion resistance of EPBF-processed Ti-6Al-4V alloy has not been thoroughly researched. In this paper, Ti-6Al-4V samples processed by EPBF were treated with different heat treatment methods. All corrosion tests were performed in 3.5 wt.% NaCl solution at ambient temperature. HT800 has the highest content of β phase, and the smallest grain boundary density, and therefore has the best corrosion resistance. The corrosion current of HT800 is reduced from 0.109 µA/cm2 unheated to 0.022 µA/cm2, a reduction of 79.82%. [ABSTRACT FROM AUTHOR]

The microstructure evolution of TC18 titanium alloy (Ti-5Al-5Mo-5V-1Cr-1Fe) after β solid solution plus aging (β-STA) and β annealing slow cooling plus aging (BASCA) heat treatments were investigated in this paper. The effects of microstructure on tensile properties and plastic deformation behavior were studied. The results suggested that α lamellar structures are formed after both STA and BASCA heat treatment. A multi-scale lamellar structure consisting of micro- and nano-scaled α platelets is formed during BASCA treatment, whereas β-STA treatment mainly generated conventional lamellar structure. In addition, the alloy after β-STA treatment displayed high strength but limited elongation, while the alloy after BASCA treatment exhibited good strength-ductility combination. A model considering α/β phase boundary strengthening, solid solution strengthening and dislocation strengthening is applied to analyze the strength of the alloy. Finally, the plastic strain partition and deformation behavior of the lamellar structure are discussed. [ABSTRACT FROM AUTHOR]

This paper presents constitutive equations that describe the hot flow behaviour of Virgin (VG) X20 and rejuvenated heat-treated creep exhaust (CE) X20 steels. The study provides a foundation for determining the effect of rejuvenation heat treatment on CE steels by making comparisons to the VG steel. Hot compression tests were conducted in the temperature range of 900 °C to 1050 °C, at strain rates of 0.1–10 s−1 to a total strain of 0.6, and stress–strain curves were obtained. The flow stress curves of both steels exhibited dynamic recovery (DRV) characteristics as the main softening mechanism. Constitutive constants of steady-state stresses were determined. The stress exponents, n, were 6.62 (VG) and 5.58 (CE), and the apparent activation energy values were 380.36 kJmol−1(VG) and 435.70 kJmol−1 (CE). Analysis of the activation energies showed that VG steel had better workability properties than CE steel and was easier to deform at high temperatures. Constitutive equations for predicting the flow stress in the two steels were established. This were verified by statistical tools: Pearson's correlation coefficient (R) and Absolute Average Relative Error (AARE). The results showed R-values were, 0.98 (VG) and 0.99 (CE), and the AARE values for VG were 4.17% and 9.01% for CE. The statistical parameters indicated a good correlation between the experimental and predicted values. The constitutive equations therefore adequately described the flow stress behaviour of both steels and can therefore efficiently analyse industrial metal forming schedules. [ABSTRACT FROM AUTHOR]

This paper examines sandstones of varying particle sizes within the coal-bearing strata in the Fugu area of northern Shaanxi. Employing high-temperature heat treatment, the study performs tests at different temperatures (25 ~ 600 ℃) on rock samples under both oxygen and nitrogen environments. Utilizing nitrogen adsorption tests combined with fractal dimension analysis, we investigate the pore structure and fractal characteristics of sandstones with varying particle sizes in coal-bearing formations. The results indicate that the total pore volume (aperture range 0.35 ~ 500nm), specific surface area, and average pore diameter of sandstone increase with temperature. Moreover, smaller particles result in more pronounced changes in the sandstone's pore structure. At the same time, in comparison to the oxygen environment, sandstone treated in a nitrogen environment undergoes multiple occurrences of molecular layer nitrogen adsorption, leading to a higher degree of pore damage. In addition, the fractal dimension of sandstone pores decreases with rising temperature. Under high-temperature conditions, the pores undergo a transformation from the initial irregular crack structure to a homogenized pore structure. The weakening of non-uniformity contributes to the decrease in fractal dimension. [ABSTRACT FROM AUTHOR]

This paper presents the results of studying the evolution of the structure and mechanical properties of 12Cr–2W ferritic/martensitic steel after cold rolling and additional heat treatment. X-ray diffraction analysis, transmission electron microscopy, and electron backscattering diffraction were used to study the structure. A significant increase of tensile strength up to a tensile strength of 1380 MPa was observed after cold rolling to 50% reduction and subsequent re-quenching from the austenite region. Compared to samples subjected to standard treatment, the use of this combined treatment led to the increase of impact toughness by 22 times up to 550 kJ/m2. The principles of achieving enhanced strength and toughness by reducing the grain size and increasing the fraction of carbides and the share of coincident site lattice (CSL) boundaries are discussed. [ABSTRACT FROM AUTHOR]

Punica granatum belongs to the Lythraceae family is one of the most important subtropical fruits native to Iran. Although the production of fruit has increased recently, there is still a gap between demand and supply. Improper handling, transportation, packaging and storage, mechanical damage, and susceptibility to chilling injury and its related physiological disorders during long-term storage are the most important causes of pomegranate postharvest losses. Fruit quality is lost with visible symptoms such as weight loss, shriveling, husk scald, fungal rot, aril color degradation, and off-flavor during long-term storage. Preserving the quality is the most important goal of the postharvest physiology industry. To minimize both qualitative and quantitative postharvest losses, it is crucial to apply appropriate knowledge and technologies during both the harvest and postharvest stages of pomegranate production. This helps to maintain the quality and shelf life of the fruit. This paper reviewed recent studies that used simple, eco-friendly, synthetic and organic plant growth regulator treatments in underdeveloped and developing countries, including proper packaging according to consumer demand and safe preservatives application, which significantly reduces postharvest losses and improves overall quality of pomegranate fruit and arils. [ABSTRACT FROM AUTHOR]

Heat treatment is a common manufacturing process in the automotive industry used to produce high-performance metal components such as aluminum cylinder heads and steel gear sets. While a heat treatment schedule incorporating a quenching cycle, either through high-velocity air flow or immersion in liquids, can yield parts with durable mechanical properties, an unintended consequence of the intense quenching process is the introduction of thermal residual stress. This stress often is identified as a leading cause for quality issues related to high-cycle fatigue in aluminum engine components or geometric distortion in steel gear sets. Since thermal residual stress is caused by uneven cooling of the materials within the parts, an effective strategy for controlling thermal residual stress would involve directly managing the quenching processes. By reducing the temperature gradient inside the parts during quenching, the quality issues can be improved. Prior to the advent of computer simulation technology, the choice of quench media and the design of quenching recipes were often based on intuitive engineering judgment at best and trial-and-error iterative methods at worst. With the advancements in computational fluid dynamics (CFD) methodology, the quenching process can now be modeled through computer simulations for accurate calculation of temperature profiles and cooling histories of quenched parts. While CFD methods have the potential to manage quenching processes and mitigate thermal residual stress, it is important to note that CFD methods are not a one-size-fits-all solution for all quenching problems. Different quenching processes require different simulation strategies. Furthermore, CFD methods still require calibration and validation before they can be effectively utilized as virtual engineering tools, replacing traditional physical tryouts and experimental methods. The objective of this paper is to develop quenching simulation methodologies that can accommodate various heat treatment requirements and be used to optimize quenching processes, thereby managing quality concerns associated with thermal residual stress. While this research focuses only on two common quenching methods in engine component manufacturing, namely air quenching and water quenching for aluminum components, the principles and methodologies can be extended to other quenching methods based on convective motion of quenching media. Additionally, this research includes the parameterization and calibration of conjugate heat transfer models at the fluid-metal interface, which form the core of CFD simulation technologies. [ABSTRACT FROM AUTHOR]

This research paper examines the effect of different solution heat treatments parameters (temperature and time) on Al–3.39%Cu–2.26%Mg (wt%) alloy's microstructure, thermal, mechanical and corrosion properties. 5754 alloy and Al–Cu alloy are used to make Al–3.39%Cu–2.26%Mg (wt%) by gravity die casting. Solution heat treatment at different temperature and time (500 °C-10 min, 500 °C-4h, 530 °C-10 min and 530 °C-2h). As-cast Al–Cu–Mg alloy have α-phase and eutectic phase. After solution heat treatment and aging, precipitates phases is observed in microstructure. X-ray diffraction analysis results have shown that a precipitate phase [S phase (Al2CuMg)] gets formed in as-cast conditions but undergoes dissolution during the solution heat treatment process. As-cast Al–Cu–Mg alloy has a Brinell hardness value of 77.2 HB. As-cast alloy has S (Al2CuMg) precipitate phase increases hardness by precipitation strengthening. After solution heat treatment and aging, Brinell hardness reduces. After solution heat treatment (500 °C for 4 h) and aging (200 °C for 5 h), Brinell hardness values becomes 63.6 HB (− 17.6% decrease). Corrosion resistance improves after the solution heat treatment due to the dissolution of the precipitate phase, forming an almost single-phase solid solution. The as-cast alloy exhibits a peak compressive stress of 494.2 MPa, which increases after solution heat treatment and water quenching to 572.7 MPa (without aging). After aging, peak compressive stress decreases to 508.4 MPa. Failure strain for the as-cast alloy is 39.6%, reducing to 31.1% after solution heat treatment and water quenching. It again increases to 43.1% after aging. [ABSTRACT FROM AUTHOR]

Surface engineering techniques provide an effective way to improve surface properties of metals and alloys such as wear resistance, hardness, and corrosion resistance. Fluidized processing offers advantages such as excellent heat and mass transfer and intimate gas-solid contact. Such processing suffers from some technical problems. This paper critically reviews the main practical problems of particle attrition, particle agglomeration, heat and mass transfer, and distortion of complicated geometries. These problems are interrelated. The surface engineering processes require an in-depth quantitative investigation to develop a reliable control strategy. In addition, modeling and simulation are basic to achieve process control. Future research trends should focus on measures to avoid the inhibiting effects of these critical problems. The design problem of distortion control in heat treatment processes needs thorough investigation. The quenching power of fluidized beds is flexible and very effective. Designers and operators should carefully consider the design implications regarding the related problems. This review showed clearly how critical these problems are to surface engineering processes. [ABSTRACT FROM AUTHOR]

The ultraprecision machining of the mold surface is important because the performance of optical components produced using optical injection is related to the surface roughness and shape precision of the mold core. To process hard-to-cut mold core materials such as stainless steel, electroless nickel-phosphorus (NiP) plating is applied to the surface of the substrate, and ultraprecision processing is performed on the plating surface using diamond turning (DT) and magnetorheological finishing (MRF). Although MRF processing can remove tool marks caused by diamond turning and improve shape accuracy, it suffers from poor processability for NiP. In this paper, an ultraprecision processing method with a heat treatment process was presented to improve the MRF processability of electroless NiP. The plating was heat-treated under each condition and subjected to DT processing followed by MRF. The surface roughness and reflectance were measured and evaluated after processing. As a result, the surface roughness of NiP subjected to a 1-h heat treatment at 450 °C significantly decreased from Ra 7.0 nm to Ra 1.5 nm when compared to the specimen that did not undergo any heat treatment. An improvement in surface roughness confirmed that reflectance improved by more than 9% and 18%, respectively, compared to that for the diamond-turned and non-heat-treated specimen. These results confirmed that the MRF performance was improved through the NiP heat treatment process and contributed to quality improvements in ultraprecision injection optical parts. Furthermore, this technology can be applicable to various fields that used NiP plating, including the manufacturing of metal reflectors in the visible and ultraviolet regions. [ABSTRACT FROM AUTHOR]

The paper analyzes the possibility of creating a titanium porous fiber material for implants, which is made of fibers of various transverse sizes and has gradient pore architecture. The architecture of the porous space, structure, and mechanical characteristics of such material have been studied. It is shown that the strength of the porous fiber material can be improved by increasing the temperature of diffusion bonding and by performing hydrogen heat treatment. The specifics of the mechanical behavior and fracture of the material samples were studied by performing a fixed-end bending test. [ABSTRACT FROM AUTHOR]

The given document provides a list of upcoming events in the field of materials science and engineering. These events include conferences, symposiums, and forums that cover a wide range of topics such as superalloys, cold spray technology, power generation, materials science, digital transformation in the steel industry, corrosion prevention, thermal conductivity, microelectronics failure analysis, and more. Each event offers opportunities for professionals, researchers, and industry experts to share knowledge, discuss advancements, and explore the latest developments in their respective fields. Contact information for each event is provided for further inquiries. [Extracted from the article]

In this paper, the microstructure evolution of TC17 titanium alloy formed by laser solid forming were analyzed, and the influence of solution and two-stage aging heat treatment on the microstructure homogenization and room temperature tensile properties were investigated. The extension of heat treatment temperature and time will lead to the size and volume fraction of primary lath α phase increasing, but decreasing for secondary α phase. Aging has no effect on the change of grain morphology but leading to the primary α lath coarsening. The hardness is the lowest at the secondary solution temperature of 750 °C. The strength and plasticity of heat-treated samples suffering 920 °C/0.5 h/ water quenching + 750 °C/1 h/water quenching + 630 °C/4 h/air cooling match well. The anisotropy is basically eliminated at the secondary solution temperature of 830 °C. [ABSTRACT FROM AUTHOR]

Collapse mechanism dictates plateau behavior for a lattice. Sharp large drops in this region are due to formation of diagonal shear bands. They may ruin energy absorption capacity of lattice. This paper is an attempt to evaluate the possibility of improving collapse mechanism in favor of energy absorption. A significant number of tests were conducted to investigate the influence and effectiveness of changes in cell topology, solid material properties, and relative density. It was demonstrated that alteration of solid material properties (through heat treatment) as well as relative density can affect fluctuations in the plateau region significantly. This has been possible through replacing shear bands with normal layer failure, or through thickening the shear band and smoothening the transitions. One of the practical achievements for this study is that the best energy absorption performance was obtained at relative density ranging from 20 to 30%. At this range, the specific absorbed energy (energy per unit weight) reaches its maximum peak for all examined lattices. However, magnitude of the peak is highly dependent on the lattice topology. This highlights the superiority of lattices as engineered structures over conventional metallic foams. Among the wide range of examined strut- and surface-based lattices, face-centered cubic (FCC) and Schwarz D lattices performed the best for weight-sensitive energy absorption applications. [ABSTRACT FROM AUTHOR]

Aluminum–copper-based alloy has a broad liquidus to solidus temperature range, making it susceptible to the formation defects such as pores and shrinkage pores during the process of solidification. Hence, ultrasonic vibration and squeeze casting can help to refine the microstructure and eliminate the formation of pores. In this paper, we used an optical microscope, scanning electron microscope, transmission electron microscope, differential scanning calorimetry, and thermal analysis to study the ultrasonic treatment (UT) and squeeze casting (SC) on the as-cast and heat-treated microstructure of Al–Cu–Mn alloys. The results show that a significant refinement can be obtained by the compound field compared with that of the individual field. The applied UT time is 30 s and 120 s, respectively. The smallest grain size and the finest Al2Cu particles are observed in the alloy with a treated time of 120 s. This is due to the ultrasonic field breaking the dendrites and promoting the flow of molten Al; squeeze casting increases the cooling rate and stimulates the nucleation temperature of α-Al. The size of the θ′ phase after compound field treatment is smaller because more Cu atoms are dissolved in the Al matrix, so the θ' strengthening phase is finely dispersed in the Al alloy matrix. It is concluded that the compound field of UT and SC is a potentially advantageous process to refine the microstructure of Al alloys. [ABSTRACT FROM AUTHOR]

In this paper, the Al–K2ZrF6–KBF4 reaction system, a melt reaction method, was used to prepare in situ ZrB2/AA6111 particle-reinforced aluminum matrix composite. The modification of friction stir processing (FSP) and T6 heat treatment (HT) was carried out for this composite for the first time. The reinforcing particles in the stirring zone after FSP+HT were refined from 1.7–1.9 to 0.1–0.3 μm. The grain size was refined from 10–50 to 2–5 μm and then slightly coarsened to 3–10 μm. The tensile strength of the FSP stirring zone is 193.40 MPa, the elongation is 29.33%, and the average hardness is 60 HV. The hardness of the stirring zone is not uniform and fluctuates in a large range of 53–80 HV. After the T6 heat treatment, the tensile strength of the stirring zone increased by 63.8% to 316.75 MPa. The tensile strength was 13% higher than that of T6-6061. The elongation remained at 30.12% and did not decrease. The elongation is 10% higher than that of other 6xxx aluminum alloys and composites after T6 heat treatment. The plasticity-reduction of the conventional alloy after T6 heat treatment was solved. The property is more uniform and the average hardness is 120 HV. Calculated by the theoretical model, the yield strengths of the stirring zone of the original composite, FSP, and FSP+HT composites were more than 96% consistent with the experimental values. [ABSTRACT FROM AUTHOR]

This paper provides the resulting finite element simulation of structure formation processes and stress-strain behavior of titanium alloys subjected to electromechanical hardening. It is demonstrated that the pulsed thermal impact of an alternating current promotes to the formation of the regular surface structure with intermittent hardened and non-hardened metal fragments. The similar periodic nature is inherent to the residual stress fields: the areas of compressing and tensioning stresses are alternating in the hardened fragments and in the interlayers of the non-hardened metal. [ABSTRACT FROM AUTHOR]

The Bi2WO6/carbon (BWO/C) micron flowers are synthesized by hydrothermal method combined with heat treatment using the sodium tungstate and bismuth nitrate as well as palm bark carbon as raw materials. The palm bark carbon was prepared firstly by hydrothermal method combined with high-temperature treatment. The BWO/C was characterized by XRD, SEM, and TEM techniques. The BWO/C took on morphology of irregular micron flowers with an average diameter of about 0.5 μm which were assembled from nanoparticles. The BWO/C was investigated as anode material by battery test system and electrochemical workstation. The specific capacity of BWO/C could maintain at 436.1 mAh·g−1 after 200 cycles, which is much better than that of pure BWO (Bi2WO6). The passable reasons for BWO/C to behave outstanding electrochemical properties were discussed in our paper. The BWO/C is a promising anode material for future application. [ABSTRACT FROM AUTHOR]

This paper reports the microstructure and corrosion behavior of a Nb-containing stainless steel surfacing layer prepared by tungsten inert gas (TIG) powder surfacing. The focus was to achieve a clear understanding of the relationships between the Nb-addition and cavitation erosion behavior. In order to eliminate the microstructure inhomogeneity of as-welded samples, solution heat treatment was carried out. It is considered to set the heat treatment temperature at 1150 °C and 1250 °C to minimize the precipitation phase. Results showed that due to the Nb addition the as-welded 22Cr9Ni3MoNb surfacing layer had higher hardness, a lower pitting potential, and better cavitation erosion resistance. Because of the existence of a great quantity of precipitates, heat treatment at 1250 °C had an adverse effect on the mechanical properties and cavitation erosion resistance of surfacing layer samples. [ABSTRACT FROM AUTHOR]

A dual-phase cast steel with high silicon content has been developed to resist low-stress abrasive wear. The alloy is composed of Fe–0.3C–2.5Si–0.5Cr–0.3Mo–0.1Nb, and the Y block was produced using an investment casting process with an induction melting furnace. Following casting, the block was homogenized and subjected to intercritical annealing heat treatments at 825, 850, and 875 °C before being tempered at 350 °C. The microstructure of the specimens was studied by using optical (OM) and scanning electron microscopy equipped with image analysis software and an energy-dispersive X-ray spectroscopy analyzer. Mechanical properties were evaluated using Vickers hardness and tensile tests at room temperature. The tribological behavior of the specimens was determined using the pin-on-disk wear test method with abrasive paper at a force of 20 N (0.6 MPa). The results showed that the microstructure of the intercritical annealed steels consisted of polygonal and acicular ferrites and tempered martensite accompanied by niobium carbide. The martensite volume fraction, hardness, and yield strength increased with increasing IA temperatures, but the tensile strength remained relatively stable. Additionally, the tribological investigation indicated that the optimal wear resistance was achieved at 850 °C, and micro-cutting was the primary wear mechanism. [ABSTRACT FROM AUTHOR]

Fe-Si-B-Cu-Nb nanocrystalline alloys have been commercially applied at power electronics. However, few research works are focused on improving high-frequency magnetic properties in the alloys. In this paper, the effect of additional magnetic field annealing temperature on high frequency soft magnetic properties of Si-rich FeSiBCuNb nanocrystalline ribbon was investigated. The as-quenched FeSiBCuNb amorphous alloys were crystallized annealing at 550 °C × 60 min for precipitating nanocrystalline α-Fe(Si) phase. Then the crystallized annealed alloy cores carried out additional transverse magnetic field annealing, and the induced uniaxial anisotropy Ku gradually increases from 9.4 to 21.6 J/m3 with increasing the annealing temperatures from 360 to 520 °C. By comparison with the non-magnetic field annealing sample, the μe of nanocrystalline cores with extra field annealing reduces at about the range of 1–30 kHz but gets significant improvement at 50–200 kHz, the Q improves and Ps decrease at all frequencies of 1 ~ 200 kHz. After the magnetic field is annealed at 480 °C, the core achieves optimal high-frequency properties of μe = 37.9 k (f = 100 kHz), Q = 0.87, and Ps = 30.94 W/kg. The improvement of high-frequency properties in cores upon transverse magnetic field annealing can be attributed to the fact that the magnetic domains appear in a rectangular band arrangement and are perpendicular to the longitudinal direction of the ribbon. When the magnetic cores operate in a dynamic magnetization field, the periodic magnetization is mainly characterized by domain rotation. [ABSTRACT FROM AUTHOR]

Middle-deep geothermal reservoirs, rich in energy, experience deep burial, high temperature, and intense three-dimensional stresses, causing noticeable elastic–plastic rock deformation under high confining pressure. However, existing researches primarily focused on elastic–plastic properties under various confining pressures, overlooking the impact of high temperature on granite's behavior. To address this, we conducted compression experiments at seven temperature points (25–600 °C) under varying confining pressures (0–15 MPa). The results reveal that increasing confining pressure prolongs the plastic yielding stage, linearly enhances compressive strength, and shifts rupture mode from brittle to expansion shear damage. Conversely, under constant confining pressure, compressive strength decreases with rising temperature, accompanied by more intricate artificial cracks. Rock cohesion, internal friction angle, and wave velocity decrease due to increased thermal damage micro-cracks. Heat treatment over 500 °C significantly increases porosity and pore throat radius, explaining heightened plasticity in hot dry rocks. These findings offer theoretical and technical insights for understanding elastic–plastic fracture mechanisms during hydraulic fracturing in middle-deep geothermal reservoirs and enhancing heat recovery efficiency. [ABSTRACT FROM AUTHOR]

The Mg-5Sn-3Zn-1Mn alloy with varying silicon addition samples were casted as per the calculated weight percentage. The present work is to study and understand the solution heat treatment and ageing of Mg-5Sn-3Zn-1Mn-xSi alloys. The heat treatment procedure was framed for the duration of 18 h and 480ºC as per the trial and error method. After the solution heat treatment, ageing was done at 450ºC and 6 h for all the prepeared samples. The characterization tests were conducted on the samples to analyse the metallurgical changes and their results were discussed. The intermetallic formed was identified by using SEM–EDS. The modification of Mg2Si intermetallic and refinement was observed for both the eutectic and primary phases. Similarly the hardness and tensile tests were conducted to reveal the mechanical properties. After the heat treatment process, and compare with the untreated. The effect of formed precipitate Mg2Sn, Mg2Si were correlated with the improved tensile strength of the alloys. [ABSTRACT FROM AUTHOR]

Lattice metamaterials based on three-period minimum surface (TPMS) are an effective means to achieve lightweight and high-strength materials which are widely used in various fields such as aerospace and ships. However, its vibration and noise reduction, and damping properties have not been fully studied. Therefore, in this study, the TPMS structures with parameterization were designed by the method of surface migration, and the TPMS structures with high forming quality was manufactured by laser powder bed fusion (LPBF). The mechanical properties and energy absorption characteristics of the beam and TPMS structures were studied and compared by quasi-static compression. The modal shapes of the beam lattice structures and TPMS structures were obtained by the free modal analysis, and the damping properties of two structures were obtained by modal tests. For the two structures after heat treatment with the same porosity of 70%, the yield strength of the beam lattice structure reaches 40.76 MPa, elastic modulus is 20.38 GPa, the energy absorption value is 32.23 MJ·m-3, the damping ratio is 0.52%. The yield strength, elastic modulus, energy absorption value, and damping ratio of the TPMS structure are 50.74 MPa, 25.37 GPa, 47.34 MJ·m-3, and 0.99%, respectively. The results show that TPMS structures exhibit more excellent mechanical properties and energy absorption, better damping performance, and obvious advantages in structural load and vibration and noise reduction compared with the beam lattice structures under the same porosity. [ABSTRACT FROM AUTHOR]

The finite element method combined with the experiment analyzed the evolution mechanism of the plastic strain state and warping deformation of the TA2/Q345R composite plate during heat treatment. Then, the factors influencing plastic strain state and shape warping in the composite plate were discussed. The results show that during the heat treatment process, the composite plate’s internal strain state and macroscopic shape state are impacted by the thermal strain and bending strain between the heterogeneous metal layers, and both are in a continuous dynamic variation state. Therefore, the ultimate deformation behaviour of the composite plate depends on the accumulation and inheritance of plastic deformation during heat treatment. There is a critical value of the composite ratio and the total thickness of the composite plate, respectively, which determines the direction of the warpage after heat treatment. [ABSTRACT FROM AUTHOR]

Purpose: Altered hemodynamics caused by the presence of an endovascular device may undermine the success of peripheral stenting procedures. Flow-enhanced stent designs are under investigation to recover physiological blood flow patterns in the treated artery and reduce long-term complications. However, flow-enhanced designs require the development of customised manufacturing processes that consider the complex behaviour of Nickel-Titanium (Ni-Ti). While the manufacturing routes of traditional self-expanding Ni–Ti stents are well-established, the process to introduce alternative stent designs is rarely reported in the literature, with much of this information (especially related to shape-setting step) being commercially sensitive and not reaching the public domain, as yet. Methods: A reliable manufacturing method was developed and improved to induce a helical ridge onto laser-cut and wire-braided Nickel–Titanium self-expanding stents. The process consisted of fastening the stent into a custom-built fixture that provided the helical shape, which was followed by a shape-setting in air furnace and rapid quenching in cold water. The parameters employed for the shape-setting in air furnace were thoroughly explored, and their effects assessed in terms of the mechanical performance of the device, material transformation temperatures and surface finishing. Results: Both stents were successfully imparted with a helical ridge and the optimal heat treatment parameters combination was found. The settings of 500 °C/30 min provided mechanical properties comparable with the original design, and transformation temperatures suitable for stenting applications (Af = 23.5 °C). Microscopy analysis confirmed that the manufacturing process did not alter the surface finishing. Deliverability testing showed the helical device could be loaded onto a catheter delivery system and deployed with full recovery of the expanded helical configuration. Conclusion: This demonstrates the feasibility of an additional heat treatment regime to allow for helical shape-setting of laser-cut and wire-braided devices that may be applied to further designs. [ABSTRACT FROM AUTHOR]

The influence of cubic and tetragonal systems of nano-sized ceramic barium titanate powder on hemolytic activity, free radical processes and antioxidant activity was studied. The physicochemical properties of BaTiO3 obtained by heat treatment in air at 800°C and 1200°C of the precursor synthesized by the sol-gel method were investigated. Based on X-ray phase analysis in conjunction with Raman spectra and heat capacity measurements, it was found that the crystal structure of BaTiO3 calcined at 1200°C is a tetragonal crystal system, while that of BaTiO3 calcined at 800°C is a cubic crystal system. The analysis of the scanning electron microscopy method in combination with the dynamic light scattering method showed a distribution of nanosized particles from 50 to 250 nm for BaTiO3 at 800°C and from 100 nm to 240 nm at 1200°C. Depending on the processing temperature, the powders were found to have different pore sizes: at 800°C - micropores and at 1200°C - mesopores. [ABSTRACT FROM AUTHOR]

This document is a special issue of the Journal of Materials Engineering & Performance focused on residual stress analysis. It highlights the importance of understanding residual stress distribution in engineering materials and its impact on component performance and reliability. The issue includes a selection of rigorously peer-reviewed papers, with more to be published later in 2024. The guest editors express their gratitude to the authors and peer reviewers for their contributions, as well as acknowledging the individuals and organizations that supported the creation of this special issue. [Extracted from the article]

Additive manufacturing opens new possibilities for designing light-weight structures using aluminium alloys. The microstructure of two Al alloys and their corrosion resistance in NaCl and natural seawater environments were investigated. The newly designed Al-Mn-Cr-Zr based alloy showed a higher corrosion resistance than reference AlSi10Mg alloy in both environments in as printed and heat-treated conditions. The corrosion initiated in the Al matrix along the precipitates in the alloys where the Volta potential difference was found the highest. The coarser microstructure and precipitate composition of the new Al-alloy led to the formation of a resistant passive film which extended the passivity region of the Al-Mn-Cr-Zr alloy compared to the AlSi10Mg alloy. The effect of heat treatment could be seen in the microstructure as more precipitates were found in between the melt pool boundaries, which affected the corrosion initiation and slightly the pitting resistance. Overall, this study shows that a newly designed Al-alloy for additive manufacturing has a suitable corrosion resistance for applications in marine environments. [ABSTRACT FROM AUTHOR]

This research aims to present a sonochemical synthesis method for high-purity willemite nanopowders. Initially, zinc silicate hydrate nanoparticles were created using a modified sonochemistry method in which zinc salts and waterglass were used as starting materials to obtain zinc silicate precipitate under pH-controlled conditions (11–11.5) and Argon gas flux. Following that, the precipitate was heat treated at various temperatures. TGA/DSC, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dispersive X-ray spectrometry (EDX), and N2 gas adsorption characterizations were also used to assess phase changes, morphological properties, microstructures, and chemical composition. The formation temperature of a well-crystalline willemite monophase was determined to be 890 °C, and this was supported by XRD analysis. The synthetized material had high homogeneity and excellent purity, according to EDX elemental mapping. Its nanometric nature was further confirmed by microscopic observations (SEM, TEM). Notably, compared to previously reported methods, the aforementioned technique uses a moderate synthesizing temperature, making it economical for mass production and potentially useful in a variety of industrial fields, including ceramics, paints, plastics, biomaterials, and composites, among others. EDX elemental mapping demonstrated high homogeneity and excellent purity of the material. Microscopic observations (SEM, TEM) further confirmed its nanometric character. Notably, the aforementioned method employs a moderate synthesizing temperature compared to previously reported methods, making it cost-effective for mass production with potential applications in various industrial fields, such as ceramics, paints, plastics, biomaterials, and composites, among others. [ABSTRACT FROM AUTHOR]

The purpose of present work was clarified the structural information of complex silicate glass, find out links between basalt glass structures and basalt fibers, and provide theoretical support for the selection of raw materials for continuous basalt fibers as well as stable production and performance characterization. In this study, basalt glasses were prepared using four types of basalts from different origins and a portion of the prepared basalt glass was subjected to secondary fusion, after which, and basalt fibers was prepared. The above-obtained samples were analyzed and tested using X-ray diffraction, Raman spectroscopy, Nuclear Magnetic Resonance and other characterization techniques. The results showed that there was high crystalline tendency for the samples with high iron contents, the dielectric constant and dielectric loss of basalt glasses increased with increasing TFe2O3 content in raw materials, the fiber structures were consistent with the structure of water-cooled glasses, and the silicate glass tended to depolymerize with the gradual increase of the heat treatment temperature. Water-cooled basalt glass exhibits structural consistency with basalt fiber, inside which, the silicon oxygen network performs as layered and chain like. [ABSTRACT FROM AUTHOR]

Stainless steels are used in a wide range of complex environments due to their excellent corrosion resistance. Multiphase stainless steels can offer an excellent combination of strength, toughness and corrosion resistance due to the coexistence of different microstructures. The microstructure and mechanical properties of a novel cast multiphase stainless steel, composed of martensite, ferrite, and austenite, were investigated following appropriate heat treatment processes: solution treatment at 1,050 °C for 0.5 h followed by water quenching to room temperature, and aging treatment at 500 °C for 4 h followed by water quenching to room temperature. Results show reversed austenite is formed by diffusion of Ni element during aging process, and the enrichment of Ni atoms directly determines the mechanical stability of austenite. The austenite with a lower Ni content undergoes a martensitic transformation during plastic deformation. The tensile strength of the specimen exceeds 1,100 MPa and the elongation exceeds 24% after solid solution, and further increases to 1,247 MPa and 25% after aging treatment. This enhancement is due to the TRIP effect of austenite and the precipitation of the nanoscale G-phase pinning dislocations in ferrite and martensite. [ABSTRACT FROM AUTHOR]

High variations in juvenile wood properties in the radial direction and its worse performance than mature wood make it less suitable for some applications and often treated as waste material. This study aimed to assess how thermal modification affects the chemical composition and the physical, mechanical and swelling properties of Scots pine juvenile and mature wood. An additional goal was to evaluate if the modification can equalise the differences in selected properties of juvenile wood to those of mature wood so that from waste material, juvenile wood can become a fully-fledged raw material for various industrial applications. Thermal treatment at 220 °C influenced wood chemical composition, degrading mainly hemicelluloses but also affecting cellulose and lignin, which resulted in a reduction of hydroxyls and carbonyl/carboxyl groups. These changes were more pronounced for mature than juvenile wood. It reduced mass loss and swelling rate, and increased swelling pressure in the tangential and radial directions to a higher degree for juvenile than mature wood. Changes in mechanical properties in compression were statistically significant only for mature wood, while wood hardness remained unaffected. Although the applied heat treatment improved the performance of juvenile wood by reducing its swelling rate, it did not equalise the examined properties between juvenile and mature wood. Since higher juvenile wood proportion is expected in the wood supply from the future intensively managed forests, there is still a need to find suitable modification methods or better processing techniques so that instead of being thrown away as waste, it could be used broadly in various industrial applications. [ABSTRACT FROM AUTHOR]

REBCO has been used extensively as coated conductors applied to superconducting magnets due to its exceptional superconducting properties. As a REBCO superconductor, YbBa2Cu3O7−y (Yb123) has a low melting temperature, making it suitable for use as an intermediate medium connector while preparing the superconducting joint. However, there is still uncertainty about the formation mechanism of Yb123 and the synthesis of this superconductor has not been fully understood. Therefore, this study systematically investigated the phase transformation process of Yb123 during heat treatment in flowing oxygen. The results indicated that Yb123 sample with the highest phase purity could be obtained by annealing at 927 °C or 937 °C but not in between, respectively. Furthermore, a quantitative phase analysis revealed that the sample annealed at 937 °C had a phase purity greater than 80 wt%. Additionally, a strong c-axis texture was observed in the bulk Yb123 superconductor prepared at 937 °C. Meanwhile, the superconducting results revealed that the bulk sample's Tc was 89.9 K, and its self-field critical current densities at 4.2 K and 77 K were 1.3 × 105 A/cm2 and 5.0 × 103 A/cm2, respectively. Based on the results mentioned above, the phase transformation process and formation mechanism of Yb123 in flowing oxygen were elaborated. [ABSTRACT FROM AUTHOR]

Many gregarious insect species use aggregation and alarm pheromones. The bed bug, Cimex lectularius L., emits an alarm pheromone (AP), a 70/30 blend of (E)-2-hexenal and (E)-2-octenal, when threatened. Bed bugs avoid temperatures above 43 °C, which are lethal to bugs and used commercially as spatial heat treatments to manage infestations. However, the interaction of bed bug AP in heat avoidance has not been investigated. The goal of this research was to: 1) determine if bed bugs emit AP as an alarm response to heat exposure, and 2) quantify the behavioral responses of conspecifics to AP emitted by heat-exposed bed bugs. Using a selected ion flow tube mass spectrometer, we found that bed bugs responded to lethal and sublethal heat exposure by emitting AP. The Harlan laboratory population emitted more pheromone than a laboratory adapted field population from Florida (McCall). Harlan females emitted the most AP, followed by Harlan males, McCall females and males. In separate behavioral experiments, we showed that conspecifics (i.e., recipients) reacted to AP released by heat exposed bed bugs (i.e., emitters) by frantically moving within 50 mm and 100 mm test arenas. The Harlan recipients reacted to AP in 100 mm areas, whereas the McCall strain did not, indicating a short area of effectiveness of the AP. Synthetic AP components tested in behavioral experiments caused identical effects as the natural AP blend released by heat-exposed bed bugs. [ABSTRACT FROM AUTHOR]

As a maraging steel, Corrax, is used in many engineering applications in the manufacturing, aerospace, and medical industries thanks to its properties such as high strength, hardness and corrosion resistance. However, these high specifications can cause some issues for manufacturing operations such as forging, machining, grinding. In addition to that, using heat treatment applications changes materials' mechanical specifications, affecting the material's behavior during machining. Therefore, it is important to characterize the influences of different heat treatment conditions on the material's property and behavior. In this study, the effects of heat treatment process on the mechanical properties, drilling machinability and corrosion resistance of Corrax steel were experimentally investigated with the samples of solution heat treated and aged at 400 °C, 525 °C, 600 °C, and 700 °C. The machinability was evaluated based on thrust force, chip morphology, hole quality, and tool wear. The results showed that the thrust force, torque and hole quality depend on feed rate, cutting speed, and mechanical properties affected by aging treatment. The highest hardness (47.4 HRC), ultimate tensile strength (1720 MPa), maximum elongation (33%), and toughness (198 jm-3) were obtained for the sample which aged at 525 °C for four hours, consequently the highest cutting force and surface roughness results were measured for this sample. Better hole surface quality and less burr formation were observed in the samples aged at 600 °C and 700 °C, and not-aged. On the other hand, while the highest value of corrosion potential were measured in the sample aged at 400 °C, the lowest corrosion potential value were measured in the sample aged at 700 °C. [ABSTRACT FROM AUTHOR]

The effects of 0.1 wt.% Ca addition, heat treatment, and SPD processing using the MaxStrain module of the Gleeble thermomechanical simulator on the microstructure, mechanical properties, and electrical conductivity of Cu–0.7Mg (wt.%) alloy were investigated in this work. The binary alloy exhibited a single-phase microstructure, whereas the ternary alloy featured uniform dispersion of Cu5Ca intermetallic particles inside the grains as well as on grain boundaries. These particles resulted in an average hardness that was 33% higher than that of the binary alloy, as well as 13% higher yield strength and 13% higher ultimate tensile strength. The heat treatment process not only enhanced the yield strength and ultimate tensile strength of the samples, but also resulted in the partial spheroidization of Cu5Ca particles within the microstructure of the ternary alloy, resulting in its improved ductility. Following MaxStrain processing, ternary samples exhibited a smaller grain size and a higher fraction of high-angle grain boundaries than binary samples, which was attributed to the vital role of Cu5Ca intermetallic particles in hindering the dislocation motion during deformation. MaxStrain-processed samples exhibited marginally lower electrical conductivities than their initial counterparts; yet, all MaxStrain-processed samples satisfied the electrical conductivity threshold for classification as HSHC Cu alloys. [ABSTRACT FROM AUTHOR]

In this work, multicomponent PEEK coatings with PTFE particles and TiN nanoparticles were developed on Ti-6Al-4V alloy substrates using electrophoretic deposition (EPD) and post-EPD heat treatment. Three different polyelectrolytes involving chitosan, PAZO and sodium alginate were used to enable the co-deposition of all particles on one electrode. All polyelectrolytes were effective and enabled coating deposition through electrosteric stabilization of suspension. The EPD mechanism consisted of the adsorption of the dispersant on the surface of the particles and the imparting of a positive (chitosan) or negative (PAZO, sodium alginate) charge. Heat treatment densified the coatings but also caused microcrack formation in the coating with chitosan, shrinkage of the polymers in the coating with PAZO, and open porosity in the coating with sodium alginate. Coatings obtained from suspension with chitosan showed excellent adhesion strength and scratch resistance, higher that those deposited from suspensions containing PAZO or alginate. The introduction of TiN and PTFE particles into the PEEK matrix resulted in a simultaneous reduction of the friction coefficient and wear rate of the titanium alloy in the case of coatings with chitosan and alginate. These coatings are promising for improving the wear and friction properties of titanium alloys. [ABSTRACT FROM AUTHOR]

The ten-layered NiTi walls were manufactured by wire arc additive manufacturing (WAAM) on Ti substrate pre-heated at 20 °C, 200 °C, 300 °C or 400 °C. It was found that an increase in the substrate temperature increased the sharpness of [001] texture and led to smooth variation in the Ni concentration in the NiTi phase on sample height that affected the martensitic transformation parameters. Annealing at 500 °C for six hours aligned the Ni distribution in the NiTi phase and decreased its concentration due to the formation of Ni4Ti3 precipitates. As a result, starting in the fifth layer, the martensitic transformation temperatures became independent of the distance from the substrate and the substrate temperature. In annealed samples, the substrate temperature affected the shape memory and superelastic behaviour. The recoverable and irreversible strain decreased upon an increase in substrate temperature because they were affected by the texture that was not destroyed by annealing. [ABSTRACT FROM AUTHOR]