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To enhance the service life and application range of titanium alloys in the aerospace sector, Ti-Zr-B-C coatings with varying B 4 C contents (0–30 wt%) on TC11 titanium alloy was fabricated by laser cladding. The microstructure and anti-ablation were investigated in the present work. The results show that the whisker-like TiB phases and granular TiC and ZrC phases were observed in the coatings due to the in-situ reactions. With increasing the content of B 4 C, the number of reinforcing phases in the coating increased and distributed uniformly, resulting in the improvement of the microhardness up to 803.8HV. Furthermore, due to the formation of TiO 2 -ZrO 2 -B 2 O 3 dense multiphase oxide layer on the surface during the ablation process, the coating with 20 wt% B 4 C exhibited the best anti-ablation at 1400ºC, the mass ablation rate (MAR) and linear ablation rate (LAR) were −2.62 mg/s and 3.67μm/s, respectively, which were just 62.8 % and 50.07 % in comparison with the substrate. This is mainly attributed to the formation of TiO 2 -ZrO 2 -B 2 O 3 layer is beneficial to reduce the infiltration of O 2 and the evaporation of liquid B 2 O 3 , leading to the excellent anti-ablation. • The TiB, TiC and ZrC reinforcing phases were in-situ formed in the Ti-Zr-B-C coating via laser cladding. • With increasing the content of B 4 C, the microhardness of the coating increased gradually. • The coating with 20wt% B 4 C exhibited the best anti-ablation among all the coatings. [ABSTRACT FROM AUTHOR]

Surface dents may occur on both rail head and wheel tread and have a deep influence on their microstructures. This investigation aims at exploring the microstructure evolution and RCF of wheel/rail materials with spherical dents. The experimental results, obtained through a suitable instrumented roller-rig, highlight the different microstructure evolutions not only between rail and wheel, but also between front and rear areas of dent. Electron backscattered diffraction data shows that the grains around dent on wheel have higher strain, misorientation and quantity of large angle grain boundaries than those on rail roller, leading to a weaker RCF resistance in wheel rollers. Meanwhile, cracks tend to propagate in front area of dent on rail and rear area of dent on wheel. [ABSTRACT FROM AUTHOR]

Decarburization means carbon in rail material lost in the hot rolled process. It changes the microstructure of rail materials and will influence their rolling contact fatigue (RCF) characteristic. The objective of this study is to explore the effect of decarburized layer on rolling contact fatigue and propagation mechanism of crack under the wet condition using a rolling-sliding wear testing machine. The results show that the crack growth rate on the decarburized rail roller is over 4 times than that on the non-decarburized rail. Small pitting presents on the non-decarburized rail roller, which is dominated by transgranular crack. While, long mouth surface crack dominates on the decarburized rail roller and the cracks mainly grow along the ferrite line or the grain boundary. With the cycles increasing, the surface cracks of decarburized rail roller gradually break and forms spalling damage, eventually expands to bulk spalling. Meanwhile, the crack growth mechanism changes back to the transgranular propagation and propagates in depth with a large angle when the decarburization is worn off. [ABSTRACT FROM AUTHOR]

The cobalt coating with an average thickness of 15–20 nm was uniformly plated on the surface of ultra-fine WC powders by electroless plating in the present work. The effects of electroless plating condition parameters on the deposition rate were studied. It was found that the deposition rate increased with the increase of CoSO 4 ·7H 2 O content, pH value, complexing agent concentration, and bath temperature, while decreased with the increase of reducing agent (NaH 2 PO 2 ·H 2 O) concentration. Furthermore, the cobalt deposition rate empirical equation and activation energy were determined. The results show that the activation energy ( E a ) for the electroless cobalt on WC substrates is approximately 54.65 kJ/mol. [ABSTRACT FROM AUTHOR]

Decarburization can remain on the surfaces of rail head steels and affect their wear and damage processes. The current research explored the influence of a decarburized layer on wear resistance and damage behavior of rail materials using a rolling–sliding wear testing machine. A decarburized layer decreases the hardness and wear resistance of rail steels, and the wear rate of a decarburized rail is over twice that of the same steel without decarburization. Multi-layer peeling appears on rail rollers without decarburization, but a decarburized layer changes the damage mechanism of the rail steel. With an increase in the depth of decarburization, the damage of rail roller turns from major spalling to pitting and peeling. In addition, surface fatigue cracks become more serious as depth increases. By contrast, shallow decarburization has little effect on rolling contact fatigue (RCF) of the rail material. Only when the depth of the decarburization exceeds a certain thickness (i.e., about 0.5 mm based on the present results), RCF damage sharply worsens as decarburization depth increases. Furthermore, adhesive wear features are obvious on the rail roller only when a decarburized zone remains at the wear surface. [ABSTRACT FROM AUTHOR]

The Nb-30Ti-18Al alloys doped with the amounts of 0 at%, 1 at% and 5 at% carbon were prepared by arc melting and annealing. The effects of carbon addition on the microstructure and mechanical properties of Nb ss /Nb 3 Al in situ composites as well as the strengthening mechanisms were investigated. The results showed that during annealing at 1200 °C, supersaturated Nb ss decomposed and Nb 3 Al phase precipitated in C-free alloy, while carbide decomposed with the precipitation of Nb 3 Al in C-doped alloys. Furthermore, the orientation relationship of Nb 3 Al phase and the surrounding (Nb, Ti)C was observed in Nb-30Ti-18Al-5C (NA5) alloy. Additionally, with increasing the carbon content, the compressive strength of alloys at high temperature were improved significantly ascribed to the occurrence of solid solution and volume fraction increase of strengthen phase, while the fracture toughness decreased due to the volume fraction decrease of Nb ss . [ABSTRACT FROM AUTHOR]

Due to excellent chemical stability, high rigidity, superior corrosion and wear resistance, aluminum oxynitride (AlON) has been considered as one of most promising candidate ceramic materials in high-performance structural, advanced abrasives and refractory fields. However, it usually exhibited relatively low flexural strength and poor fracture toughness. The study is aimed to develop silicon carbide (SiC) and zirconium nitride (ZrN) nano-particulate reinforced AlON composites with improved mechanical properties and fracture resistance via a hot-press sintering process. It was found that the addition of ZrO 2 nanoparticles would be transformed into ZrN during sintering. Due to the pinning effect of SiC and ZrN nano-particles positioned at grain boundaries of micro-sized AlON particles, the presence of SiC and ZrN nano-particles resulted in the reduction of both porosity and grain size, and a change of fracture mode from intergranular cracking in AlON to intragranular cracking in composites. With presence of 8 wt% SiC and 5.2 wt% ZrN nano-particles, the relative density, microhardness, Young’s modulus, flexural strength and fracture toughness increased. Different toughening mechanisms including crack bridging, crack branching and crack deflection were observed, thus effectively increasing the crack propagation resistance and leading to a considerable improvement in flexural strength and fracture toughness. [ABSTRACT FROM AUTHOR]

The in-situ laminated Nb/Nb 5 Si 3 composite was prepared by spark plasma sintering. The microstructures and mechanical properties of the laminated Nb/Nb 5 Si 3 composite were investigated in present work. It could be found that, alternant distribution microstructures of Nb ss and Nb 5 Si 3 layers were observed after sintering. The Nb/Nb 5 Si 3 composite exhibited fracture toughness of 11.2 MPa·m 1/2 , and the predicted fracture toughness was estimated by the Ashby model. Moreover, the deviation of the experimental value from the predicted value was discussed. In addition, the compressive strength of the in-situ laminated Nb/Nb 5 Si 3 composite was measured at 1400 °C and compared with that of the unidirectionally solidified Nb-17.5Si alloy. [ABSTRACT FROM AUTHOR]

Precipitates in an aged Al-Cu-Mg-Ag alloy have been characterised using atomic-resolution energy-dispersive X-ray spectroscopy (EDXS) scanning transmission electron microscopy (STEM) and high-angle annular dark-field (HAADF) STEM. A metastable precursor phase, designated Ω′, which forms as thin plates on {111} α planes of the α-Al matrix phase, is found for Ω precipitate which is the key strengthening constituent in the Al-Cu-Mg-Ag alloy. The Ω′ phase has a hexagonal structure that is distinguishably different from that of the Ω precipitate, and this hexagonal structure is isomorphous to that of the single unit-cell thick T 1 precipitate plates in Al-Cu-Li alloys. Our proposed hexagonal structure is also supported by density functional theory (DFT) calculations. One interesting feature of Ω′ phase is that its thickness is invariably one unit-cell height, ∼0.915 nm thick. In contrast to the commonly accepted view that shear is not involved in diffusional phase transformations, the formation of Ω′ phase involves an appreciably large shear component, which is equivalent to two 30° Shockley partial dislocations, and the magnitude of this shear component is significantly larger than the dilatational strain associated with the α-Al → Ω′ structural transformation. With continued ageing, the metastable Ω′ phase transforms in-situ into the Ω phase. Compared to the direct α-Al → Ω structural transformation, the existence of Ω′ considerably lowers the energy barrier to the nucleation of Ω via the reduction of the shear strain. [Display omitted] [ABSTRACT FROM AUTHOR]

• The wear performance of the defected rail materials under various slip ratios and contact stresses was investigated. • The surface damage of the defected rail materials under various slip ratios and contact stresses was studied. • The effect of slip ratio and contact stress on crack propagation mechanisms near the dent was discussed. The defects on rail surface may have negative effects on the rolling contact fatigue (RCF) performance of the rail materials. This investigation researched on the RCF behaviors of the defected rail materials under various slip ratios and contact stresses. The results show that both the wear loss and the average crack length increase if the slip ratio or the contact stress increases. Moreover, the surface damage characteristics change from simple adhesion spots to significant fatigue crack grouping when slip ratio and contact stress rise. Finally, the experimental results also highlight that the slip ratio provides the deformation area for crack initiation whereas the contact stress accelerates the crack propagation by emphasizing the geometric effects. [ABSTRACT FROM AUTHOR]

Abstract: Surface energy effects can play a significant role in the case of nanoscale materials and structures due to their high surface to volume ratio. In this paper, the general three-dimensional asymmetric problem for an elastic layer of nanoscale thickness that is bonded to a rigid substrate and subjected to tangential loading at the surface is considered. Muki''s integral transforms method for classical elasticity is extended to investigate the influence of surface energy effects on the elastic field based on the Gurtin–Murdoch continuum model. Hankel integral transforms are used to solve the non-classical boundary value problems related to a tangential concentrated load and a uniformly distributed tangential circular patch load. Explicit analytical solutions are obtained for the corresponding boundary-value problems. Selected numerical results are presented to illustrate the influence of surface energy effects and layer thickness on the elastic field. [Copyright &y& Elsevier]

Abstract: Aluminum oxynitride (AlON) exhibits excellent stability, chemical and mechanical properties. Corrosion resistance to molten steel is an important performance index of ceramic refractories. While silicon carbide (SiC) particles have been proven to improve the mechanical properties and thermal shock resistance of AlON ceramic, the corrosion of AlON and SiC–AlON composites by molten steel were unknown. The aim of this investigation was to evaluate the corrosion resistance to molten steel and identify the underlying mechanisms of AlON ceramic and 8wt% SiC–AlON composites at the temperature of 1550°C for 30min. Due to the reaction between AlON and molten steel, a solid product of Al2O3 is detected in the corrosion region. Besides, some round shaped pores form and increase toward the sample surface in the corrosion region. The thickness of corrosion region of AlON ceramic is about 150μm, indicating that the AlON ceramic has an excellent corrosion resistance to molten steel. However, the corrosion resistance of 8wt% SiC–AlON composites to molten steel can be characterized with a penetrated depth of approximately 250μm. This is mainly attributed to the thermal dissociation of SiC and the reaction between SiC and molten steel. [Copyright &y& Elsevier]

Abstract: Aluminum oxynitride (AlON) has been considered as a potential ceramic material for high-performance structural and advanced refractory applications owing to its excellent stability and mechanical properties such as high rigidity and good chemical stability. Thermal shock resistance is a major concern and an important performance index of refractories and high-temperature ceramics. While zirconium nitride (ZrN) particles have been proven to improve mechanical properties of AlON ceramic, the thermal shock behavior has not been evaluated yet. The aim of this investigation was to identify the thermal shock resistance and underlying mechanisms of hot-pressed 2.7% ZrN–AlON composites by a water-quenching technique over a temperature range between 225°C and 275°C. The residual strength and Young''s modulus after thermal shock decreased with increasing temperature range and thermal shock times due to large temperature gradients and thermal stresses caused by abrupt water-quenching. The presence of nano-sized ZrN particles exhibited a positive effect on the improvement of both residual strength and critical temperature difference of AlON ceramic due to the toughening effects, the higher thermal conductivity of ZrN, the refined grain size and the reduction of porosity. Different toughening mechanisms including crack deflection, crack bridging and crack branching were observed during thermal shock experiments, thus effectively enhancing the crack initiation and propagation resistance and leading to a considerable improvement in thermal shock resistance in the ZrN–AlON composites. [Copyright &y& Elsevier]

Abstract: Aluminum oxynitride (AlON) has been considered as a potential ceramic material for high-performance structural and advanced refractory applications. Thermal shock resistance is a major concern and an important performance index of high-temperature ceramics. While silicon carbide (SiC) particles have been proven to improve mechanical properties of AlON ceramic, the high-temperature thermal shock behavior was unknown. The aim of this investigation was to identify the thermal shock resistance and underlying mechanisms of AlON ceramic and 8wt% SiC–AlON composites over a temperature range between 175°C and 275°C. The residual strength and Young''s modulus after thermal shock decreased with increasing quenching temperature and thermal shock times due to large temperature gradients and thermal stresses caused by abrupt water-quenching. A linear relationship between the residual strength and thermal shock times was observed in both pure AlON and SiC–AlON composites. The addition of nano-sized SiC particles increased both residual strength and critical temperature from 200°C in the monolithic AlON to 225°C in the SiC–AlON composites due to the toughening effect, the lower coefficient of thermal expansion and higher thermal conductivity of SiC. The enhancement of the thermal shock resistance in the SiC–AlON composites was directly related to the change of fracture mode from intergranular cracking along with cleavage-type fracture in the AlON to a rougher fracture surface with ridge-like characteristics, crack deflection, and crack branching in the SiC–AlON composites. [Copyright &y& Elsevier]

Abstract: Aluminum oxynitride (Alon) has been considered as a potential ceramic material due to excellent stability, chemical and mechanical properties such as high rigidity and good chemical stability, but it has relatively low strength and poor fracture toughness. The aim of this study was to investigate a type of silicon carbide (SiC) nano-particulate reinforced Alon composites with improved mechanical properties and fracture resistance via hot-press sintering. The addition of SiC nano-particles resulted in a reduction of both porosity and grain size, and a change of fracture mode from intergranular cracking in the monolithic Alon to intragranular cracking in the composites due to the pinning effect of SiC nano-particles positioned at grain boundaries or triple junctions of micro-sized Alon particles. With 8wt% SiC nano-particles addition, the relative density, microhardness, Young''s modulus, flexural strength, and fracture toughness all increased. Different toughening mechanisms including crack bridging, crack branching and crack deflection were observed, thus effectively increasing the crack propagation resistance and leading to a considerable improvement in the flexural strength and fracture toughness of the composites. [Copyright &y& Elsevier]

Abstract: Silicon carbide (SiC)–aluminium oxynitride (Alon) ceramic composites exhibited improved mechanical properties, but the high temperature oxidation behaviour was unknown. The aim of this investigation was to identify oxidation characteristics and kinetics of 8wt% SiC–Alon composites over a temperature range between 700°C and 1200°C in air. The Alon matrix and SiC particles near the surface were oxidized to form Al2O3 and SiO2, respectively. The starting oxidation temperature of Alon was observed to be about 1000°C. While the addition of nano-sized SiC particles resulted in a reduced starting oxidation temperature due to the large cumulative surface area and high total surface energy, the oxidation resistance at higher temperatures of 1100°C and 1200°C was remarkably enhanced. The oxidation kinetics changed from a linear weight gain for pure Alon into a logarithmic weight gain for the composites due to the formation of a dense protective oxidation layer arising from the presence of SiO2. [Copyright &y& Elsevier]

Abstract: Aluminium oxynitride (Alon) exhibits excellent stability, high rigidity and good thermal shock resistance, but it has relatively low strength and poor fracture toughness. The aim of this investigation was to develop a new type of zirconium nitride (ZrN) nano-particulate reinforced Alon composites via a change of ZrO2 nano-particles during sintering. A reduction of porosity and grain size was observed in the composite. With increasing amount of ZrN nano-particles up to 2.7%, the relative density, hardness, Young''s modulus, flexural strength, and fracture toughness all increased. When the ZrN nano-particles exceeded 2.7%, while the flexural strength and fracture toughness decreased slightly, the density, hardness and Young''s modulus continued to increase. Different toughening mechanisms including crack bridging, crack branching and crack deflection were observed, thus effectively increasing the crack propagation resistance and leading to a considerable improvement in the flexural strength and fracture toughness of the composites. [Copyright &y& Elsevier]

Abstract: Highly transparent, p-type conducting SnO2:Al films derived from thermal diffusion of a sandwich structure Al/SnO2/Al multilayer thin films deposited on quartz substrate have been prepared by direct current and radio-frequency magnetron sputtering using Al and SnO2 targets. The deposited films were annealed at various temperatures for different durations. The effect of thermal diffusing temperature and time on the structural, electrical and optical performances of SnO2:Al films has been studied. X-ray diffraction results show that all p-type conducting films possessed polycrystalline SnO2 with tetragonal rutile structure. Hall-effect results indicate that 450°C for 4h were the optimum annealing parameters for p-type SnO2:Al films, resulting in a relatively high hole concentration of 7.2×1018 cm−3 and a low resistivity of 0.81Ωcm. The transmission of the p-type SnO2:Al films was above 80%. [ABSTRACT FROM AUTHOR]

Abstract: Distribution of electromechanical field near electrode tips is closely related to the reliability of ferroelectric multilayer actuators. In this paper, the deformation and stress concentrations around the electrode tip in two multilayer actuator designs, partially and fully cofired, are investigated by means of experimental measurement and numerical simulations. The digital speckle correlation method (DSCM) is used to measure the full displacement field near the electrode tip with the high spatial resolution. The paths of electric breakdown and cracks initiated from the edge of electrodes were observed. With the proposed Double Gibbs free energy criterion, a fully coupled nonlinear electromechanical finite element method based on domain-switching mechanisms is developed and the simulation results agree well with the experiments. It is found that the crack-like “defects” in the partially cofired layered actuators, i.e. the interlayer gaps filled with soft insulating wax, can significantly reduce the maximum tensile stress level compared with that in “perfect” fully cofired actuators, which implies that the partially cofired design is more reliable than the fully cofired one. Further optimization on geometrical dimension of actuators is also carried out. [Copyright &y& Elsevier]

Glasses compositions which can be expressed by (100-x)GeS2–xGa2S3 (x=0, 10, 20, 30 mol%), 70GeS2–(30-x)Ga2S3–xCdS (x=0, 10, 15, 20 mol%), and (100-x)GeS2–x[0.5Ga2S3–0.5CdS] (x=0, 10, 20, 30, 40 mol%), were obtained by the melt-quenching technique. Differential scanning calorimetry (DSC) and visible-IR transmission were used to characterize the thermal and optical properties of these glasses, together with refractive index and density measurements. These homogeneous glasses have relatively high glass transition temperatures (338–436 °C), good thermal stabilities, broad transparencies (0.45–11.5 μm), large refractive indices (2.01–2.25), and large densities (2.68–3.18 g cm-3). The long-wavelength cutoff edge is found near 12 μm due to the multiphonon Ge–S and Ga–S vibrations. The compositional dependences of selected properties were also discussed by making reference to the structural variation. [Copyright &y& Elsevier]

Defects such as dents on the rail surface might induce severe rolling contact fatigue (RCF) and then threaten the running safety of railway vehicles. This study aims to explore the initiation and propagation of RCF cracks around dents with different sizes through observing both surfaces and cross-sections of the defective rail. The experiments are conducted on a wheel/rail twin-disc machine. Results indicate that the microstructure evolution process around the dent can be divided into three main stages, namely crack initiation, crack propagation and dent removal. Dents in different sizes act very similarly in each stage, including the position, the crack growth path and the final appearance after the dent has been fully worn off. However, dents in different sizes cause different lifetimes of crack initiation and different lasting times of dents at each stage. For the lager dent, cracks initiate later but propagate for a longer time period, so the dent size plays an important role in the RCF evolution process. • Dents with three different sharpness were made on the rail sample. • The evolution process of microstructure of defected rail material was studied. • Dent size plays a vital role in the wear and RCF damage of defected rail. • RCF cracks propagate in a "C" shape at the leading edge of dent. • Shaper dents initiate cracks later but need more time to be worn off. [ABSTRACT FROM AUTHOR]

Examines spectroelectrochemical titration studies involving the binding of the infrared-active probe ligand carbon monoxide to the heme a3/CUB site of bovine heart cytochrome c oxidase. Enzyme preparation; Instrumentation and data handling; Infrared spectroelectrochemical titrations; Theoretical fitting of the resultant spectroelectrochemical data.

Surface dents on railroad rails may be caused, for example, by the drop of freight goods or the impact of ballast rocks and may have a deep effect on the rail service life. To better understand this problem, this investigation aims at exploring the rolling contact fatigue behavior of the rail materials (as, for example, PD3 steel) after being impacted by two kinds of hard bodies: a simple spherical steel ball and a more realistic ballast rock. The results show that the residual tensile stress, which is distributed on the shoulders of the dent, decreases the rolling contact fatigue (RCF) resistance of the material around the dent. Moreover, the unbalanced wear behavior between the two shoulders of the dent makes the situation even worse on the side of the dent where the tangential force acts firstly. Finally, due to the higher martensite hardness with respect to the matrix material, the crack propagates faster around the dent in presence of white etching layer on the bottom of the dent itself. • The residual tensile stress on the shoulders of rail dents was modelled through FE models. • The unbalanced wear on the shoulders of the rail dent leads to a sever fatigue damage on one side of the dent. • The crack growth mechanism on two typical dents was studied in detail. [ABSTRACT FROM AUTHOR]

A face-centered cubic (FCC) non-equiatomic high-entropy alloy (HEA), Cr 10 Mn 10 Fe 60 Co 10 Ni 10 , is processed via cold-rolling and subsequent annealing at 800 − 1200 °C with different cooling methods. All the annealing treatments lead to fully recrystallized microstructures with various grain sizes and precipitate types. The mechanical properties under uniaxial tension are obtained along with microstructure characterizations of postmortem samples. The sample annealed at 800 °C followed by furnace cooling yields a reasonable combination of high strength and good ductility. The yield strength and ultimate tensile strength are 43% and 19% higher than those of the sample annealed at 800 °C followed by water quenching, with only a uniform elongation ∼ 6% reduction. The yield strength variations of all the annealed samples are explained with a structure-based strength model. After fracture, all the samples show strong 〈 111 〉 texture along the tensile direction. Besides dislocation slip, deformation twinning and multiple phase transitions contribute to high strength and effective work hardening as additional deformation mechanisms. The newly formed hexagonal close-packed and body-centered cubic phases follow the Shoji–Nishiyama and Kurdjumov–Sachs orientation relations with the FCC matrix, respectively. Given the "treatment method − microstructure − mechanical property" relationship in this study, combining the advantages of the steel and HEAs, this kind of Fe-rich HEA bears great potentials to serve under practical conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The dispersion of WC particles is critical to the microstructures and properties of WC-based alloys. The ultra-fine WC powders were uniformly dispersed in aqueous media via sodium dodecyl sulfate (SDS) with physical means. The influence of dispersion conditions such as concentration of dispersant, dispersion time and solid-liquid ratio on the powders dispersion was investigated by sedimentation test in present work. The particle size and distribution of WC powders, phase analysis and microstructure were characterized by the laser particle size analyzer, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Transmission electron microscope (TEM) and Zeta potential respectively. The results show that SDS was adsorbed and scattered on the WC powders, which could enhance the stability and dispersibility of suspension by the electrostatic effect. The diameter of dispersed WC powders ranged from 0.2 to 0.8 μm. The corresponding dispersive mechanisms of SDS were electrostatic repulsion and static hindrance, which kept the dispersibility and stability of the suspension. Furthermore, the optical dispersing time, solid-liquid ratio and the concentration of SDS for the dispersed WC powders in this work is 3 h, 1:50 and 1.44 g/L, respectively. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effects of Lactobacillus rhamnosus GG (LGG; ATCC 53013) on growth performance and hepatotoxicity in calves fed a single dose of aflatoxin B1 (AFB1) and to investigate the absorption, distribution, and elimination of AFB1 and the hydroxylated metabolite aflatoxin M1 (AFM1) in rumen fluid, blood, and excretions. Twenty-four male Holstein calves were blocked for body weight and age and were randomly assigned to 1 of 3 treatment groups: (1) untreated control, (2) treated with 4.80 mg of AFB1 (AFB1 only), or (3) treated with 1 × 1010 cfu of LGG suspension and 4.80 mg of AFB1 (AFB1 plus LGG). The calves received LGG suspension in 50 mL of phosphate-buffered saline daily via oral administration for 14 d before and on the day they received a single oral dose of AFB1. Body weight was recorded at the beginning of the study (before LGG administration), at the day of AFB1 administration, and at the end of the trial. Rumen fluid, blood, urine, and feces samples were collected continuously for 96 h after AFB1 administration. Average daily gain (ADG) and plasma biochemical parameters were analyzed, and concentrations of AFB1 and AFM1 in the samples were determined for monitoring excretion pattern and toxicokinetics. The results showed that ADG was lower in AFB1-treated animals; LGG administration partially mitigated the decrease in ADG (0.85 ± 0.08 vs. 0.76 ± 0.18 kg of gain/d). The AFB1 treatment increased plasma aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase levels. Administration of LGG alleviated the AFB1-induced increase in plasma enzymes activity. The excretion patterns of AFB1 and AFM1 were surprisingly regular; toxins were rapidly detected in all samples after a single oral dose of AFB1, and the peak of toxins concentrations was sequentially reached in rumen fluid, plasma, urine, and feces (except AFM1 in rumen fluid), followed by an exponential decrease. The excretion curves showed that AFB1 and AFM1 concentrations were the highest in feces and urine, respectively. Administration of LGG decreased the concentrations of free AFB1 and AFM1 in rumen fluid and reduced the release of toxins into plasma and urine. Toxicokinetic parameters (except for the time of maximum concentration and the terminal half-life) were reduced by LGG administration. In conclusion, the absorption, distribution, and excretion of AFB1 and AFM1 were rapid in calves fed a single dose of AFB1. Urine was the main route for the excretion of AFM1, and the clearance pattern from the peak of concentration was well fitted by exponential decreasing function. Administration of LGG reduced the absorption of AFB1 in the gastrointestinal tract by increasing the excretion via the feces, thus alleviating the hepatotoxic effect of AFB1. [ABSTRACT FROM AUTHOR]

The objective of this study is to explore the rolling contact fatigue (RCF) behaviors of wheel materials with a flat under different braking conditions using a JD-1 wheel/rail simulation apparatus. The results indicates that the microstructure of wheel flat zone is composed of white etching layer (WEL), transition layer (TL), plastic deformation layer (PDL). The martensite caused by thermal effect is clarified in the WEL of wheel flat zone. There are three kinds of damage forms including the material accumulation, plowing and peeling in the front, the middle and the back of wheel flat zone, respectively. Fatigue cracks caused by impact only initiate and propagate in the back of wheel flat zone. Meanwhile, with the braking speed or braking time increasing, the fatigue damage of wheel flat zone worsen and the thickness of WEL increases, which brings an increase of fatigue crack length and propagation angle. [ABSTRACT FROM AUTHOR]

Due to the high specific stiffness and low coefficient of thermal expansion, the SiC particles are introduced to improve the dimensional stability of Al-Cu-Mg (2024 aluminum) alloy in present work. The intergrated effects of SiC and aging precipitates on dimensional stability of 2024 aluminum alloy are investigated during the two-stage aging process. It is observed that, with increasing the addition of SiC, the amount of S′ precipitates decreases, and the micro-yield strength first increases and then decreases, while the thermal strain (ε c ) first decreases and then increases. When the addition of SiC was 10 wt%, both the micro-yield strength and the thermal strain reach the optimal value. It is attributed to the effect of SiC and aging precipitates on pinning the dislocations, which would consume more stored elastic energy, thus leading to an increase in the dimensional stability of the alloy. [ABSTRACT FROM AUTHOR]

The surface crack of wheel/rail is a significant problem affecting the safety and maintenance of railway. This study presents the experimental results to explore the formation and damage mechanism of rolling contact fatigue (RCF) surface cracks of wheel/rail materials under dry condition. The results indicate that the surface cracks mouths on the rail roller are perpendicular to the resultant direction of shear force. Fatigue cracks grow along a larger angle to depth on the rail rollers than on the wheel rollers due to the difference of materials. Meanwhile, there are visible subsurface and secondary cracks as well as lamellar structure cracks. The vertical force changed in the later 1.5×10 5 cycles leads to a significant difference in the cracks propagation. [ABSTRACT FROM AUTHOR]

The stress-aging method is proposed to improve the dimensional stability of Al-Cu-Mg (2024 aluminum) alloy. Both the reduction of residual stress and the acceleration of precipitates are investigated during the stress-aging process. It is observed that some S′ particles precipitate in the alloy during stress-aging. With the external stress increase to 100 MPa, the residual stress and thermal strain (ɛ c ) decrease, while the micro-yield strength increases significantly. This is attributed to that the dislocations are effectively pinned by the uniformly distributed precipitates and the stored elastic energy diminishes remarkably, which leads to a considerable improvement of the dimensional stability of 2024 aluminum alloy. However, when further increases the external stress to 150 MPa, due to the coarsened precipitates, the residual stress and thermal strain increase, while the micro-yield strength decreases slightly. [ABSTRACT FROM AUTHOR]

Ultra-fine WC/Co composite powders were prepared by electroless plating in this study. The Co layers with an average thickness of 50–100 nm were uniformly and completely covered on raw WC particles with a diameter of 0.3–0.5 µm. The influences of electroless plating conditions on the composites were investigated. The Co layer covering on WC particles was controlled by the content of CoSO 4 ·7H 2 O, pH value and bath temperature. With increasing the content of CoSO 4 ·7H 2 O up to 25 g/L, both the weight gain and the plating rate markedly increased. However, when the content of CoSO 4 ·7H 2 O further increased to 30 g/L, while the weight gain displayed a slight decrease, the plating rate continued to increase moderately. Moreover, with the increase of pH value from 9.5 to 11, both the weight gain and the reaction time decreased. Furthermore, the plating rate exhibited an exponential relationship with the bath temperature. When the pH value, bath temperature and the concentration of CoSO 4 ·7H 2 O are 10, 80 °C and 25 g/L respectively, the weight gain of Co-coated WC composite powders is 185.1 mg/g. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the effect of slip ratio on the wear and rolling contact fatigue (RCF) of wheel/rail materials using a rolling–sliding wear testing apparatus. The results indicate that two wear types are presented in terms of wear rate: type I (mild wear) and type II (severe wear). In type I wear, cracks propagate parallel to the surface. While in type II, the peeling is aggravated and spalling can be observed. With the slip ratio increasing, the wear mechanism of rollers transforms from slight oxidation wear and peeling to severe fatigue wear and spalling. Due to the mild wear and light plastic deformation in type I, the angle and depth of cracks show no obvious differences between the wheel and rail rollers. The crack depth and angle increase in type II wear owing to severe plastic deformation, while the depth is smaller on the wheel rollers. The size of flake wear debris presents an increasing trend and the main composition is Fe 2 O 3 and metallic iron, and the content of iron diminishes with increasing oxidation. [ABSTRACT FROM AUTHOR]

• Deformation mechanism under shock compression of an additively manufactured HEA has been revealed. • Higher strain rate promotes the phase transitions in the HEA. • Elemental segregation of Mn and Ni strongly influences the phase transitions in the HEA. [Display omitted] Shock compression of an additively manufactured high-entropy alloy, Cr 10 Mn 10 Fe 60 Co 10 Ni 10 , is investigated via gas-gun plate impact. The postmortem sample shocked to 11.3 GPa is characterized with electron back-scattered diffraction and transmission electron microscopy; two phase transitions are observed, the face-centered cubic (FCC) to hexagonal close-packed (HCP) transition, and the FCC to body-centered cubic (BCC) transition. The HCP and BCC phases with different variants are observed following specific orientation relationships with the FCC matrix. The phase transitions are strongly affected by elemental segregation during the additive manufacture (the HCP and BCC phases are absent in the Mn and Ni enriched areas), and one possible reason is the increase of local stacking fault energy caused by the Mn and Ni enrichment. [ABSTRACT FROM AUTHOR]

Shock compression and spallation of a low-cost cobalt-free medium-entropy alloy (MEA), Fe 40 Mn 20 Cr 20 Ni 20 (at%), with a face-centered-cubic structure are investigated via plate impact experiments, to reveal its dynamic mechanical properties and corresponding microscopic deformation/damage mechanisms. The Hugoniot equation of state, yield strength, spall strength and pullback rate are obtained from free-surface velocity histories. Post-deformation samples are characterized with transmission electron microscopy, scanning electron microscopy and electron backscatter diffraction. The Fe 40 Mn 20 Cr 20 Ni 20 MEA exhibits a good balance in spall strength and ductility (low pullback rate) at a relatively low cost, compared to several other types of medium/high entropy alloys and steels. At sufficiently high impact velocity (e.g., 500 m s−1 here), nanoscale deformation twinning becomes a key deformation mechanism for Fe 40 Mn 20 Cr 20 Ni 20 MEA in addition to dislocation slip. During spallation, voids (i.e., damage) nucleate preferentially at grain boundary triple junctions, and grow isotropically with increasing loading. Owing to fine grains and strong plastic deformation capability of the Fe 40 Mn 20 Cr 20 Ni 20 MEA, void coalescence is accomplished by intragranular shear deformation bands and cracks, which contributes to its high ductility. • Hugoniot EOS of Fe 40 Mn 20 Cr 20 Ni 20 is obtained. • Fe 40 Mn 20 Cr 20 Ni 20 MEA exhibits good balance between spall strength and ductility. • Nanoscale deformation twinning occurs at high-velocity impact. • Voids nucleate at grain boundaries, and coalesce via intragranular fracture. [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of columnar-grained copper under casting and drawing conditions were investigated in the present work. It was found that the as-casted copper mainly consisted of continuous columnar grains with orientation preference along <100> and exhibited excellent plastic deformation ability. Moreover, the texture of columnar-grained copper transferred from <100> to <111> during the drawing process. A typical microstructural morphology as multangular-cup feature of as-casted copper as well as drawn copper was observed on the fracture surfaces. With increasing the drawn strain, the texture evolution and the grains broken occurred, leading to a significant increase in the work hardening rate and tensile strength. [ABSTRACT FROM AUTHOR]

A typical Fe-rich non-equiatomic CrMnFeCoNi high-entropy alloy (HEA), Cr 10 Mn 10 Fe 60 Co 10 Ni 10 , and the equiatomic Cr 20 Mn 20 Fe 20 Co 20 Ni 20 HEA, are investigated via plate impact experiments along with in situ free surface velocity measurements. Both the initial and postmortem samples are characterized with transmission electron microscopy and electron backscatter diffraction. These two HEAs contain a single face-centered cubic phase, are texture-free, and have similar grain sizes. Dynamic yield stress and spall strength of the non-equiatomic CrMnFeCoNi are lower by ∼55 % and 15 % than those of its equiatomic counterpart, respectively. After shock compression, dislocation slips, stacking faults, Lomer-Cottrell locks and nanotwins are found in the postmortem samples of both HEAs. Due to the reduced stacking fault energy in the non-equiatomic HEA, more deformation twins and newly formed hexagonal close-packed phases are found. For spallation, intergranular voids are larger in size but smaller in quantity than intragranular voids for both HEAs. Both intragranular or intergranular voids show strong dependence on grain boundary misorientation. [Display omitted] • Equiatomic and non-equiatomic CrMnFeCoNi are with similar grain size and weak texture. • The yield stress and spall strength of equiatomic alloy are higher. • More nano twins and newly formed HCP phase are found in nonequiatomic alloy. • Ductile spallation occurs. The HAGBs have a higher probability of inducing a void than TBs. [ABSTRACT FROM AUTHOR]

Phase transformation in a metastable body-centered cubic (BCC) high entropy alloy HfZrTiT a 0.53 is investigated via plate impact along with in situ free surface velocity measurements, postmortem microstructure characterizations and first-principles calculations. Impact-induced BCC to hexagonal close-packed transformation is observed. Compared to the single orientation relationship (the Pitsch-Schrader relationship) under quasi-static loading, an additional orientation relationship with higher phase transformation activation barrier is also involved, given the ultrahigh strain rates and complex stress condition under planar impact. [ABSTRACT FROM AUTHOR]

The effects of strain rate on mechanical properties, microstructural evolution and underlying deformation mechanisms of two kinds of interstitial CrMnFeCoNi high entropy alloys (HEAs), (CrMnFeCoNi) 99.5 C 0.5 and (CrMnFeCoNi) 99.0 C 1.0 , are investigated under quasi-static and dynamic tension. Dynamic loading is carried out via a split Hopkinson tension bar system. The pre- and post-deformation microstructures are characterized with electron back scatter diffraction and transmission electron microscopy. Both yield strength and work hardening increase remarkably with increasing strain rate. Plastic deformation in both alloys under quasi-static and dynamic loading are dominated by dislocations, stacking faults, kink bands and deformation twins. Twinning is activated easier under dynamic loading, and twin density decreases with increasing carbon content due to the increased stacking fault energy. The Khan-Liu constitutive model can describe the experimental results for these two interstitial HEAs in a wide strain range. • Both volume fraction and size of the carbides increase with the increase of C content. • The increase of C content and strain rate lead to the increase in σ Y and σ UT. • Twin density decreases with increasing C content due to the increased SF energy. • The Khan-Liu constitutive model is used to describe the deformation. [ABSTRACT FROM AUTHOR]

Abstract: A novel magnetic annealing assisted route was applied to improve the electrochemical properties of La0.67Mg0.33Ni3.0. The effects of magnetic annealing parameters, including annealing temperature, annealing time and magnetic induction density, on electrochemical performance of La0.67Mg0.33Ni3.0 hydride electrode alloys was investigated using L9 orthogonal array based on Taguchi method. Based on the analysis of signal to noise ratio and the variance, the optimum magnetic annealing parameters for La0.67Mg0.33Ni3.0 hydride electrode alloy are determined to be 1T, 1123K, and 2h. A confirmation test was conducted subsequently, and the results were found to be within the confidence interval. The discharge capacity, the cyclic stability and the electrochemical kinetics of the alloy electrode were noticeably improved by magnetic annealing. [Copyright &y& Elsevier]

Abstract: A series of Al-substituted spinel powders LiNi0.5−x Al2x Mn1.5−x O4 (0 ≤ 2x ≤ 1.0) have been prepared and the effects of Al concentration on the structural, electrochemical and thermal properties are investigated. The XRD patterns show that impurity arises when 2x ≥ 0.6. The FTIR and Raman spectra indicate that the introduction of Al in the LiNi0.5Mn1.5O4 increases the disordering degree of Ni/Mn ions, changing the spinel structure from P4332 to . Cyclic voltammetry tests show that the voltage step between Ni2+/Ni3+ and Ni3+/Ni4+ have a sudden leap at 2x = 0.075, responding to the structural difference of the spinels. The Al concentration is optimized in the range of 0.05 ≤ 2x ≤ 0.1, in which the cyclic stability and rate capability of the LiNi0.5−x Al2x Mn1.5−x O4 spinels are significantly improved. At room temperature the LiNi0.45Al0.10Mn1.45O4 presents the best cycle performance with the capacity retention of 95.4% after 500 cycles at 1C rate, and the best rate capability with the discharge capacity of 119 mAh g−1 at 10C rate, which is about 93.7% of its capacity at 0.5C. The thermal properties of the spinels have been tested by C80 calorimeter and the results show that introduction of Al in LiNi0.5Mn1.5O4 can effectively suppress the exothermic reaction below 225 °C, thus improve the safety of the high voltage cathode material. [Copyright &y& Elsevier]

• All the {112}〈111〉 twinning activation follows Schmid law below σ T , while a portion of them deviates from the law above σ T. • Twin growth in pearlite depends on orientation of an activated twinning plane relative to cementite lamellae. • Bulk plastic strain increases with increasing stress, mainly via twinning in ferrite and dislocation slip in pearlite. • Both phase transition and {112}〈111〉 twin boundaries are necessary for the occurrence of {332}〈113〉 twins. Deformation twinning in a medium carbon steel containing ferrite and pearlite under shock compression is investigated below and above the α – ε phase transition stress (σ T), within a peak stress range of 10–20 GPa. Free surface velocity histories are measured to obtain the Hugoniot elastic limit (2.7 GPa), σ T (13.3 GPa) and bulk plastic strain. Postmortem samples are characterized with electron backscatter diffraction and transmission electron microscopy. Below σ T , all the {112}〈111〉 twinning activation in ferrite and pearlite follows the Schmid law, while above σ T , approximately 1/6 of the activation deviates from the law. Propagation of the {112}〈111〉 twins in pearlite depends on the orientation of the activated twinning plane relative to cementite lamellae. With increasing peak stress, the {112}〈111〉 twin area fraction in ferrite/pearlite increases greatly/slightly; the {112}〈111〉 twin area fraction in ferrite is about 7 times that of pearlite. The {332}〈113〉 twins can only form above σ T , favoring ferrite over pearlite, and are likely to be the secondary twins originated at the {112}〈111〉 twin boundaries. [ABSTRACT FROM AUTHOR]

Abstract: The mechanical stability of the electrode plays a very important role in the long-term stability of electrochemical behavior. In this paper, multi-wall carbon nanotubes (MWCNTs) electrodes were prepared in the holes of glass directly by microwave plasma chemical vapor deposition and the electrochemical behavior of catechol at the integrated MWCNT electrodes was investigated. The oxygen plasma treated CNTs had excellent electrochemical behavior for the analysis of catechol. The catechol was detected in the linear concentration range of 1.0×10−6 mol L−1–1.0×10−3 mol L−1. And because CNTs were integrated directly on the substrate, the stable response to catechol solution showed that the carbon nanotubes electrodes had long-term stability. [Copyright &y& Elsevier]

Dynamic (up to 5500 s−1) and quasi-static compression tests are conducted on a 15 wt% B 4 C particle-reinforced Al (B 4 C/Al) composite. In situ , high-speed synchrotron X-ray phase contrast imaging and digital image correlation are employed to map mesoscale deformation fields at μm and μs scales. The bulk stress–strain curves show significant strain and strain-rate hardening under dynamic compression. The strain-rate sensitivity exponent is an order of magnitude higher at high strain rates (> 10 3 s−1) than that at low strain rates (< 10 − 2 s−1). Strain field mapping demonstrates distinct compressive strain localizations for both quasi-static and dynamic loading. Nevertheless, compressive strain localizations appear denser in spacing under dynamic loading, owing to spontaneous dislocation nucleation in both weak and strong zones. This results in a higher density of geometrically necessary dislocations, which contributes to the higher strain and strain-rate hardening of B 4 C/Al under dynamic loading. The ratio of the maximum local strain to the bulk average is ~ 1.5, and the local strain-rate enhancement cannot explain the increased rate sensitivity of B 4 C/Al under dynamic loading. Therefore, the rate-dependent deformation heterogeneity dominates the strain-rate hardening of B 4 C/Al. Postmortem analyses help correlate deformation features to particle- and grain-scale microstructures, yielding consistent results with mesoscale strain fields. [ABSTRACT FROM AUTHOR]

In this study, two different microstructures were obtained after subsolvus solution treatment (910 °C + 550 °C) and supersolvus solution treatment (1010 °C + 550 °C) in TC21 alloy. The relationship of microstructure with room and high temperature properties was studied. The results showed that at room temperature, both samples after two treatments had high hardness. At room temperature, the subsolvus sample had high tensile strength of 1070 MPa and moderate plasticity and impact toughness, while the supersolvus sample was hard and brittle. The high strength and toughness of subsolvus sample was owing to its clear basket-weave structure within finer β grains which contributes to fine grain strengthening and the increase of crack tortuosity. Poor plasticity and toughness of supersolvus sample could be mainly attributed to its incomplete basket-weave structure, coarse β grains, Widmannstatten α and some coarse α-phase in the grain boundary. Both samples showed excellent high temperature tensile properties and stability at 400 °C, the tensile strength was still as high as 1000 MPa while plasticity was significantly improved. With the tensile temperature increasing to 600 °C, the alloys showed obvious softening as the tensile strength significantly decreased and elongation increased. • TC21 alloys after subsolvus heat treatment showed an obvious basket-weave structure. • The TC21 alloy after subsolvus treatment showed high fracture strength of 1070 MPa with the elongation of 8 %. • Both subsolvus and supersolvus samples showed excellent high temperature tensile properties at 400 °C and 600 °C. • The tensile strength was still as high as 1000 MPa while plasticity was significantly improved during 400 °C tensile. • The tensile strength significantly decreased to about 500 MPa as elongation increased during 600 °C high temperature tensile. [ABSTRACT FROM AUTHOR]

Dynamic compression experiments are conducted on a heterogeneous-structured CrMnFeCoNi high-entropy alloy (HEA) at different strain rates (1000–5000 s−1) and temperatures (123–293 K) with a split Hopkinson pressure bar system. Yield strength and strain hardening rate increase considerably with decreasing temperature at 5000 s−1 (low-temperature strengthening), but are insensitive to strain rate at 173 K, which can be well described by the Zerilli–Armstrong model. Compared to typical aluminum alloys and homogeneous-structured CrMnFeCoNi HEA, the heterogeneous-structured HEA exhibits higher thermal sensitivity and strain hardening rate. Microstructural characterizations show that dislocation density in the fine-grained domains increases more drastically than in the coarse-grained domains, inducing high deformation gradient between the coarse- and fine-grained domains. At 123 K, nano-scale primary and secondary deformation twins form in grain interior, along with a great number of stacking faults on twin boundaries; the twin width and spacing in coarse grains are considerably higher than in fine grains. In addition, the twin density at 123 K is significantly higher than that at 293 K. Overall, the increased deformation twinning and deformation gradient contribute to pronounced strengthening and strain hardening with decreasing temperatures in the heterogeneous-structured HEA under dynamic compression. [Display omitted] • Dynamic compression responses of CrMnFeCoNi HEA are investigated under multiple low temperatures. • Strain localization occurs preferentially in fine grains near normal grain boundaries. • Twin width and spacing in coarse grains are significantly higher than those in fine grains. • With decreasing temperatures, twin density increases, leading to increasing strain hardening. • Increased local deformation gradient at low temperatures contributes to higher HDI strengthening. [ABSTRACT FROM AUTHOR]

Dynamic equal channel angular pressing (DECAP) and heat treatment are applied to pure Ti to achieve a strength-ductility synergy. DECAP induces a complex multiscale twin structure in Ti including four primary twin types, secondary twins and tertiary twins with multiple variants, and an increased yield strength (58% higher than the as-received Ti). Subsequent annealing at 200 ℃ and 400 ℃ leads to improved ductility and strength. The yield strength (σ y) and total elongation (ɛ t) for the Ti sample processed with DECAP and 400 ℃ annealing are 555 MPa and 30%, respectively, and its σ y ɛ t product is ∼ 45% higher than the as-received Ti. DECAP and subsequent annealing lead to a superior strength-ductility synergy in twinned Ti, providing a novel approach to produce high strength and ductility materials via dynamic deformation and subsequent heat treatment. [ABSTRACT FROM AUTHOR]

• The influence of thermal-cold cycling on dimensional stability of composite. • The microstructure, dimensional change, magnetic property, hardness were analyzed. • The underlying dimensional stabilizing mechanisms of the composite were revealed. • An optimal improvement of dimensional stability of the composite was achieved. Thermal-cold cycling (TCC) treatment was applied to improve the dimensional stability of TiC reinforced steel matrix composite materials in this study. Also, the microstructure, related properties and potential stability mechanisms were investigated. When the TCC cycles were 3, Vickers hardness reached the peak value of 1051.7 HV and relative dimensional change was only 0.012% in a natural service for 30 days. Besides, the retained austenite disappeared and residual stress dramatically decreased from −740 MPa to −357 MPa. It demonstrated that the TiC reinforced steel matrix composite possessed the best dimensional stability after 3 TCC cycles. A variety of stabilizing mechanisms, including martensitic refinement, retained austenite-martensite transformation, carbides precipitation, and residual stress release were observed, hence resulting in a significantly improvement of the dimensional stability of the composite. [ABSTRACT FROM AUTHOR]

• The influence of tempering on dimensional stability of TiC-reinforced composite. • The microstructure, hardness, thermal strain and magnetic property were analyzed. • The underlying dimensional stabilizing mechanisms of the composite were revealed. • An optimal improvement of dimensional stability of the composite was achieved. To improve the service reliability of components prepared by TiC-reinforced steel matrix composite material, tempering treatment was carried out to tailor the microstructure and properties of the composite. The aim of this study was to investigate the microstructure, properties, and dimensional stability of a TiC-reinforced steel matrix composite during tempering and to identify the underlying stabilizing mechanisms. We observed that the metastable retained austenite transformed into martensite and that residual stress released during tempering. The microstructure and properties of the composite reached an optimal state for a tempering time of 10 h. Furthermore, the relative dimensional change, Vickers hardness, thermal strain, and saturation magnetization of the composite were 0.0219%, 960.8 HV, 3.16 × 10−4, and 109.7 emu/g, respectively. Various stabilizing mechanisms, including retained austenite-martensite transformation and residual stress release, were observed during tempering, effectively improving the dimensional stability of TiC-reinforced steel matrix composites. [ABSTRACT FROM AUTHOR]