Dislocation Strengthening Research Articles

Effect of partitioning treatment on the strengthening and plasticising mechanism of one-step quenching and partitioning steels

The effects of partitioning temperature and time on the strengthening and plasticising mechanism of a one-step quenching and partitioning (Q&P) steel were investigated. The results show that as the partitioning temperature decreased, the lath martensite became finer with higher dislocation density, while the dislocation density and RA amount decreased with increasing partitioning time. Lower quenching temperature and shorter partitioning time are conducive to achieve the high ultimate tensile strength of 1377 MPa and the better total elongation of 12.3% for low-carbon one-step Q&P steels. Meanwhile, the dislocation strengthening caused by martensite and the solid solution strengthening are main strengthening mechanisms of one-step Q&P steels. In addition, a new martensite transformation kinetic model considering the influence of silicon element was established, and simultaneously, the modified CCE model predicted RA fractions more accurately for high-silicon Q&P steels, especially at lower quenching temperature.

Effect of cladding speed on the microstructure and hardness of high-hardness B-bearing Cr17Ni2 coating

The B-bearing iron-based coating produced by laser cladding exhibits super-high hardness. However, the strengthening mechanism of B-bearing Cr17Ni2 coating and non-equilibrium phase transformation during the cooling stage require further investigation. The study focused on the B-bearing Cr17Ni2 coatings produced by laser cladding at four speeds ranging from 10 mm/s to 200 mm/s. The results show that the thickness of the single layer in the coatings gradually decrease as the increase of scanning speed. The secondary dendrite arms spacing and grain size also decrease with increasing scanning speed. The microstructure of the coating consists of a martensitic phase and a eutectic phase consisting of Cr2B compounds and austenite. Combined with G\\R diagram and finite element analysis, the microstructure refining mechanism of the coating has been concluded. The effect of fine grain strengthening, solid solution strengthening, precipitation strengthening, and dislocation strengthening on hardness is investigated. It has been observed that the coating hardness increases with increasing scanning speed. This change in the hardness of the coatings is mainly because of the grain and precipitate refining.

A detailed exploration of microstructure evolution in a novel Ti–Mo martensitic steel through in-situ observation: The effect of heating rate

Rapid heating is a promising technique for achieving excellent mechanical properties. This study innovatively applies rapid heating to a novel Ti–Mo martensite steel through in-situ observation experiments. By comparing the microstructure evolutions at heating rates of 1 and 30 °C/s, the relationship between microstructure and property evolution was elucidated. The results indicate that the refined austenite grains resulting from rapid heating stem from enhanced grain nucleation, accumulated dislocations, and the increased formation of new carbides under the large superheat. Furthermore, carbide maturation predominates during the slow heating process, while rapid heating accelerates new carbide precipitation with limited carbide maturation. Moreover, during rapid heating, both coherent and non-coherent relationships were observed between the (Ti, Mo, Fe)C particles and the martensite matrix, demonstrating a remarkable pinning effect on grain boundary migration. Nevertheless, during slow heating, large-sized (Ti, Mo)C carbides were formed, presenting a non-coherent relationship with the martensite matrix. Additionally, the primary differences in strength caused by rapid heating compared to slow heating include grain refinement, dislocation, and precipitation strengthenings, with dislocation strengthening playing the dominant role.

A gradient strengthening method of wire-arc additive manufacturing coupling with surface rolling and its application

The gradient distribution of properties, which satisfies the service requirements of critical components operating in extreme environments, plays a significant role in enhancing the durability of these components. Here, a new method of wire-arc additive manufacturing (WAAM) coupling with surface rolling was proposed to construct the gradient distributed properties. The present study focuses on a typical application of this method, wherein the surface of an exhaust valve in a marine diesel engine is processed to achieve a gradient property. The gradient strengthening mechanisms were investigated through numerical simulation and physical experiments. Simulation results demonstrated that the residual tensile stress resulting from WAAM was significantly reduced and mostly converted to compressive stress after surface rolling. The initial maximum residual tensile stress of 208.6 MPa, located at the surface of the deposited valve, was reduced to −167.8 MPa after surface rolling. The depth of residual compressive stress was extended 6–7 mm from the rolled surface to the deposited zone. Analysis of microstructures revealed that three distinct zones with different microstructural characteristics were generated through the proposed method, thereby forming the gradient microstructures. Specifically, the surface rolled zone was characterized as nanocrystallines (<1 μm), refined grains (1–10 μm), and deformed grains (>10 μm), while the deposited zone and substrate corresponded to columnar grains and equiaxed grains, respectively. A wide gradient strengthening layer with an approximate thickness of 8 mm was achieved on the processed valve surface, exhibiting a hardness gradient from 314 MPa at the substrate to 566 MPa on the rolled surface. The gradient strengthening mechanisms were attributed to intrinsic material strengthening, grain boundary strengthening and dislocation strengthening.

Influence of travel speed on microstructure and mechanical behavior of Inconel 625 fabricated using wire fed laser directed energy deposition

The printing of Inconel 625 via wire-fed laser directed energy deposition is required for the near net shape fabrication of large scale components. In this study, an array of processing parameters was tested to identify a defect-free low-travel-speed and high-travel speed parameter for wire-fed laser directed energy deposition of Inconel 625. Samples printed using these parameters were subject to characterization in terms of grain morphology and tensile properties. Results showed that the high-travel-speed parameter had a refined columnar+equiaxed grain structure, whereas the low-travel-speed parameter had a columnar grain structure. The experimentally observed microstructure is correlated to the processing parameters by calculation of the solidification rate and thermal gradient. When tested perpendicular to the build direction, both parameters exhibited a similar yield strength. When tested parallel to the build direction, the high-travel-speed parameter exhibited a higher yield strength than the low-travel-speed parameter. For both parameters, samples pulled parallel to the build-direction showed a lower yield strength than samples pulled perpendicular to the build direction. The differences in yield strength for differing parameters and orientation are attributed primarily to dislocation strengthening.

Influence of various heat treatment processes behavior of a novel maraging steel coating process on the microstructure, nanoindentation pattern, and wear

Effective subsequent heat treatment is essential for achieving excellent performance in maraging steel. This paper presents the preparation of a maraging steel coating with a high content of Mo and Co elements using laser cladding technology. The study investigates the effects of direct aging treatment and solid solution-aging treatment on the microstructure, elemental distribution, crystallographic features, nanoindentation characteristics, and wear behavior of the coatings. The results indicate that all three coatings consist primarily of α-Fe with a small amount of γ-Fe, and solid solution-aging treatment effectively inhibits the martensite-to-austenite transformation. Following both heat treatments, a significant number of nanoscale precipitated phases were observed within the martensitic matrix, proving pivotal in enhancing the coatings' hardness. Notably, the solid solution-aging-treated coating exhibits excellent nanomechanical properties, with a hardness of approximately 8.39 ± 0.19 GPa, representing a remarkable 75 % improvement compared to the untreated coating. Second-phase strengthening and dislocation strengthening are identified as the primary mechanisms responsible for enhancing the solid solution-aging coating. Furthermore, solid solution-aging treatment significantly enhances the wear performance of the coatings, as evidenced by a dry sliding average friction coefficient of 0.578 and a wear volume of (3.18 ± 0.97) × 106 μm3, surpassing those of the original coatings. The observed wear mechanisms include abrasive wear, oxidative wear, and slight adhesive wear, with the precipitation of nanoscale precipitated phases playing a key role in enhancing wear resistance.

Probing the microstructure and deformation mechanism of an FeCoCrNiAl0.5 high entropy alloy during nanoscratching: a combined atomistic and physical model study.

High entropy alloys (HEAs) exhibit superior mechanical properties. However, the nanoscratching properties and deformation behaviour of FeCoCrNiAl0.5 HEAs remain unknown at the nanoscale. Here, we investigate the effect of scratching depth on the microstructural and tribological characteristics of an FeCoCrNiAl0.5 HEA using molecular dynamics simulations combined with a physical model. The scratching force increases significantly as the scratching depth increases. In the lower part of the scratching region, there is a clear atomic movement process, with the load generated in the normal direction causing the atoms to shift downwards. Noticeable shear bands are formed in the subsurface area, and they are both small and narrow compared with the pure Ni. The plastic deformation mechanism of the compressed surface is mainly governed by the formation and expansion of stacking faults during the subsurface evolution process. The evolution process of screw dislocations is similar to that of edge dislocations. In addition, the high strength and deformation resistance of FeCoCrNiAl0.5 HEAs are further evaluated by establishing a microstructure-based physical model. The combined effect of the lattice distortion strengthening and dislocation strengthening promotes the high strength of the FeCoCrNiAl0.5 HEA, which is significantly better than the single strengthening mechanism of pure metals. These results accelerate the understanding of the mechanical properties and deformation mechanisms of HEAs.

Research on the Influence of Cold Drawing and Aging Heat Treatment on the Structure and Mechanical Properties of GH3625 Alloy.

With the development of the petroleum industry, the demand for materials for oilfield equipment is becoming increasingly stringent. The strength increase brought about by time strengthening is limited in meeting the needs of equipment development. The GH3625 alloy with different strength levels can be obtained through cold deformation and heat treatment processes. A study should be carried out to further develop the potential mechanical properties of GH3625. In this study, the GH3625 alloy was cold drawn with different reductions in area (0-30%) and heat treated, and its mechanical properties were tested. The microstructure of the alloy during deformation and heat treatment was characterized by methods such as optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) based on the principles of physical metallurgy. The strength increase caused by dislocation strengthening was calculated from the dislocation density, tested by X-ray diffraction (XRD). The calculated value was compared to the measured value, elucidating the strengthening effect of cold deformation and heat treatment. The results showed that the yield strength and yield ratio of the cold-drawn alloy significantly reduced after aging at 650 °C and 760 °C. Heat treatment can make a cold-deformed material recover, ablate dislocations, and greatly reduce the dislocation density in the microstructure of the GH3625 alloy, which was the main factor in the decrease in yield strength. The work-hardening gradient of the cold-drawn material varied greatly with different reductions in area. When the reduction in area was small (10%), the hardness gradient was obvious. When it increased to 30%, the alloy was uniformly strengthened as the deformation was transmitted to the axis. This study can provide more mechanical performance options for GH3625 alloy structural components in the petrochemical industry.

The investigation of strength-ductility mechanism of bimodal size SiCp/Mg–Zn matrix composite

Mg–Zn–Al matrix composites reinforced with bimodal-size SiCp (average size of ∼8 μm and ∼60 nm) are fabricated by semi solid stirring casting process and extrusion process. The influence of bimodal size SiCp on microstructure and texture evolution, mechanical properties as well as work hardening behavior of Mg–Zn–Al matrix composites are investigated. The results reveal that the area fraction of unrecrystallization (unDRX) region decreases from 12.8 % of matrix alloy to 5.2 % of 9 wt% m-SiC+1 wt% n-SiC/Mg–6Zn–3Al-0.5Ca(M9N1) composite, and the average grain size (AGS) is reduced sharply with addition of SiCp, which decreases from 7.3 μm of matrix alloy to 0.9 μm of M9N1 composite. The addition of micron SiCp (m-SiCp) promotes the generation of nano precipitates, and the precipitate size is reduced further after the addition of nano SiCp (n-SiCp). The intensity of basal texture decreases firstly and then increases with the addition of m- and n-SiCp because of the pinning effect from n-SiCp and nano precipitates for grain boundary. The bimodal-size SiCp particles have been observed to significantly enhance the strength of the composite. The M9N1 composite demonstrates exceptional performance, and its yield strength and ultimate tensile strength is 322 MPa and 360 MPa, respectively. The exceptional strength of the composite can be attributed to various strengthening mechanisms, including grain refinement, precipitate strengthening, dislocation strengthening, and the load transfer effect.

Effect of aging temperature on microstructure and properties of cold-rolled Cu-Ni-Si alloy

The aging process plays a pivotal role in shaping the microstructure of Cu-Ni-Si alloys, a typical kind of precipitation-strengthened Cu alloy. This process significantly affects both the mechanical and electrical properties of the final Cu alloy strips. In this study, Cu-Ni-Si alloy sheets underwent a 90 % reduction through cold rolling at room temperature, followed by heat treatment at temperatures ranging from 400 to 650 ℃. A comprehensive investigation was conducted into how cold rolling deformation and the aging process affect the alloy's microstructure, as well as its mechanical and electrical properties. The analysis was performed using a scanning electron microscope equipped with a backscattered electron diffraction system (SEM-EBSD), complemented by transmission electron microscopy (TEM). The findings revealed that recrystallization and precipitation occurred concurrently and were both enhanced by higher temperatures and prolonged heat treatment durations. However, recrystallization at elevated temperatures has a marginal impact on enhancing electrical conductivity and results in a significant reduction of mechanical properties. In contrast, alloys preserving the deformed microstructure benefit from multiple strengthening mechanisms, including precipitation, dislocation, grain boundary, and texture strengthening. This study offers quantitative insights into the precipitation and recrystallization behaviors of Cu-Ni-Si alloys, contributing significantly to a deeper understanding of the mass production of high-performance copper alloys.

Interface enhancement mechanism of rolled Mg/Al clad plate with particle interface control

In this study, the cold-spraying process was utilized to deposit Al particles onto an Al slab, an Mg slab, and both Al and Mg slabs to form an ultra-thin interlayer, and then the clad slabs were rolled at 400 °C, developing three roll-bonding processes: the roll-bonding process with cold-sprayed Al powder on the Al slab (CS-Al), the roll-bonding process with cold-sprayed Al powder on the Mg slab (CS-Mg), and the roll-bonding process with cold-sprayed Al powder on both the Al slab and the Mg slab (CS-Both). The effects of three different cold-sprayed Al particle interlayer processes on the mechanical properties of rolled Mg/Al clad plates were investigated to improve the mechanical properties. The microstructure, texture evolution, intermetallic compound formation, mechanical properties, and mechanisms involved in the Mg/Al clad plate rolling were systematically investigated. The results showed that the pre-bonding between the particles and the substrates through cold-spraying had a significant impact on the bonding strength of the Mg/Al clad plates, and the CS-Both process can increase the average shear strength of the Mg/Al clad plates to 49.24 MPa at a medium reduction rate of 37.5 %, 2.5 times that of the conventional rolling process. The CS-Both process constructed more evident dual microscopic three-dimensional interfaces and promoted more thorough atomic diffusion at the interface through the double-sided cold-spraying process. Meanwhile, the dual cold-sprayed Al coatings on both the Mg slab and Al slab underwent dynamic recrystallization during rolling to form a homogeneous unit with no additional coating interfaces. Fine grain strengthening and dislocation strengthening were judged to be important mechanisms for improving the mechanical performance of the interfacial layer.

Investigation of a novel laser powder bed fusion nickel-based superalloy with hf, Y addition: Melt characteristic, microstructure and mechanical properties

In order to resolve the inherent strength-ductility trade-off dilemma observed in precipitation-strengthened nickel-based superalloys with high Al and Ti content, a composition modification strategy was devised. This study explored a novel laser powder bed fusion (LPBF) René104 alloy by incorporating Hf and Y (HfY-René104), examining its melt characteristics, microstructures, and mechanical properties. The experimental results demonstrate that the addition of Hf and Y effectively improves the molten pool structure of the as-built, alters grain orientation, diminishes grain aspect ratio, promotes the formation of cellular structures, AlY phases, stacking faults (SFs), and Lomer-Cottrell (L-C) locks at macro, meso, and micro scales, respectively. The primary contributors to yield strength are grain boundary strengthening and dislocation strengthening. Moreover, a dynamic Hall-Petch effect associated with cellular structures, SFs, and L-C locks ultimately results in remarkable strength (yield strength of 823 MPa, ultimate tensile strength of 1158 MPa) and enhanced ductility (elongation of 24.6 %) of HfY-René104 alloy.

Strengthened high-temperature resistance in B4C/SiC/2024Al composite via SiC nanowires pinning grain boundary

Aiming at developing new B4C/Al neutron absorbing materials with both high thermal neutron absorption performance and high-temperature strength for neutron shielding applications, B4C/SiC/2024Al composites were fabricated by powder metallurgy process. TEM results revealed that SiC nanowires were distributed at Al grain boundaries and bonded tightly with Al matrix. Grain boundary sliding and grain rotation were efficiently restricted and prevented dislocation annihilation at GBs. The thermal stability of composite was improved by adding SiC nanowires and achieved a high-temperature strength of 163.4 ± 1.8 MPa at 573 K, which was increased by 92.2 % compared to the composite without addition of SiC nanowires. By analyzing the strengthening mechanism, dislocation strengthening was the dominant factor in the improvement of high-temperature strength. As for neutron absorption application, B4C/SiC/2024Al composite exhibited not only good high-temperature strength but also remarkable neutron absorption performance and matched thermal conductivity and coefficient of thermal expansion.

Dislocation cells tailored precipitation enhancing mechanical properties of a high Gd content Mg alloy

High Gd content Mg alloys are expected to overcome the poor heat resistance of magnesium (Mg) alloys. However, the low ductility limits their applications. Nano-precipitates is a viable method to enhance the strength without seriously plummeting ductility. In this study, ultrafine and densely arranged dislocation cells, with an average size of 27 nm, were obtained in Mg-11.5Gd-2Y-0.5Zr-0.5Ag-0.5Nd alloy after hot rolling. During the aging process, the dislocation cells facilitated the precipitation of fine and high-density β'. In the peak-aged (225 °C, 15 h) alloy, the volume fraction of β′ could reach 20.3 %, and the average length and thickness of β′ are 10 and 5.9 nm, respectively. The alloy with such a microstructure exhibited a yield strength (YS) of 403 MPa, and an EL of 8.3 % at room temperature. YS of the alloy was still 357 MPa, 310 MPa, and 206 MPa at 200 °C, 250 °C, and 300 °C, respectively. The high YS is attributed to grain boundary, dislocation, solid solution, and precipitation strengthening, among which precipitation strengthening is dominant. Moreover, the nano-β′ could be sheared, thereby coordinating the plastic deformation. Therefore, the present alloy achieved high YS while maintaining good ductility.

Microstructural and mechanistic insights into the Tension–Compression asymmetry of rapidly solidified Fe–Cr alloys: A phase field and strain gradient plasticity study

Rapid solidification in Additively Manufactured (AM) metallic materials results in the development of significant microscale internal stresses, which are attributed to the printing induced dislocation substructures. The resulting backstress due to the Geometrically Necessary Dislocations (GNDs) is responsible for the observed Tension–Compression (TC) asymmetry. We propose a combined Phase Field (PF)-Strain Gradient J2 Plasticity (SGP) framework to investigate the TC asymmetry in such microstructures. The proposed PF model is an extension of Kobayashi’s dendritic growth framework, modified to account for the orientation-based anisotropy and multi-grain interaction effects. The SGP model has consideration for anisotropic temperature-dependent elasticity, dislocation strengthening, solid solution strengthening, along with GND-induced directional backstress. This model is employed to predict the solute segregation, dislocation substructure and backstress development during solidification and the post-solidification anisotropic mechanical properties in terms of the TC asymmetry of rapidly solidified Fe–Cr alloys. It is observed that higher thermal gradients (and hence, cooling rates) lead to higher magnitudes of solute segregation, GND density, and backstress. This also correlates with a corresponding increase in the predicted TC asymmetry. The results presented in this study point to the microstructural factors, such as dislocation substructure and solute segregation, and mechanistic factors, such as backstress, which may contribute to the development of TC asymmetry in rapidly solidified microstructures.

Microstructure and mechanical properties of high-entropy diboride-based ceramic assisted by Ti3AlC2 additive

Ti3AlC2 was used as the additive to fabricate a novel (Zr0·2Ta0·2Nb0.2Hf0.2Mo0.2)B2-based (HEBTAC) ceramic using spark plasma sintering at 1900 °C. The as-prepared HEBTAC ceramic sample consists of (Ti, Zr, Hf, Ta, Nb, Mo)B2, multiscale (Zr, Hf, Ta, Nb, Mo)C, and Al2O3 phases, which are produced by the decomposition of Ti3AlC2 and subsequent exchange reaction & solid solution reactions during the sintering process. The relative density, hardness, fracture toughness, and flexural strength of the HEBTAC ceramic sample are 99.43 %, 27.92 ± 1.87 GPa, 5.84 ± 0.14 MPa m1/2, and 629 ± 8.7 MPa, respectively, which are even better than the same class of high-entropy diboride ceramics previously published. Solid-solution strengthening, dislocation strengthening and nano-HEC strengthening existed in the ceramic sample contribute to its excellent mechanical properties. The in situ formed Al2O3 and (Zr, Hf, Ta, Nb, Mo)C effectively enhances the toughness of the HEBTAC ceramic sample through the synergistic effect of intrinsic and extrinsic toughening. This study presents a new approach for reactive sintering densification of high-entropy diborides with both high strength and high toughness.

Microstructure, aging behavior, and friction and wear properties of ultrafine-grained 7050 aluminum alloy produced by cryogenic temperature extrusion machining

Cryogenic temperature extrusion machining (CT-EM), as a novel cryogenic temperature severe plastic deformation (CT-SPD) process, is an effective method to produce ultrafine-grained (UFG) materials. In this paper, the microstructure, microhardness, friction and wear properties of the UFG chips prepared by CT-EM and room temperature extrusion machining (RT-EM) were analyzed. The results show that CT-EM has a better grain refinement effect. The grain size of the CT-EM samples is smaller, the dislocation density is larger, and the microhardness is higher. After aging treatment, a large number of small secondary precipitates (η '/η) appear in the microstructure of the samples, which further improves the microhardness. This is the result of a synergistic effect of fine grain, dislocation, and precipitation strengthening. Cryogenic treatment can increase the precipitation kinetics of the secondary phase and shorten the time for the samples to reach peak hardness. The CT-EM samples have a lower friction coefficient and wear mass. With the increase of the machining velocity, the wear mechanism of the samples changes from abrasion wear to oxidation, adhesion, and fatigue wear.

Microstructure evolution, mechanical response, and corrosion resistance for a 2195 Al-Li alloy under different rolling reductions during cryorolling

This study used cryorolling (CR) and room temperature rolling (RTR) with different rolling reductions to process the 2195 aluminum-lithium alloy (Al-Li alloy, AA2195) sheets. Subsequently, the AA2195 sheets were artificially aged to the peak aging stage. Their mechanical properties, corrosion resistance, and microstructural evolution sheets were investigated using methods such as hardness testing, tensile testing, intergranular corrosion (IGC) experiments, electrochemical experiments, transmission electron microscopy (TEM), and electron probe microanalysis (EPMA). Compared to the RTR samples, the CR samples exhibited higher hardness, ultimate tensile strength, and elongation under the same rolling reduction conditions due to the combined effect of dislocation strengthening, grain boundary strengthening, and precipitation strengthening. The corrosion resistance of the RTR samples showed a declining trend with the increased rolling reduction. However, the corrosion potential of the CR samples exhibited a non-monotonic trend, first increasing and then decreasing, with the increased rolling reduction. The CR and RTR samples had similar microstructural evolution trends, leading to predominantly IGC morphologies in the IGC tests. The RTR and CR samples exhibited partial pitting morphologies at 70% rolling reduction, and the CR samples had more pronounced pitting characteristics than the RTR samples.

Cooperative roles of twinning, transformation and strain partitioning on the excellent cryogenic strength-toughness synergy of dual-heterogeneous metastable high entropy alloys

In a metastable Fe50Mn30Co10Cr10 high entropy alloy (HEA), a dual-heterogeneous structure, encompassing both grain size and dislocation heterogeneity, has been constructed to obtain excellent cryogenic mechanical performance by varying the annealing temperature (630 and 740 °C) following severe deformation. The HS-630 sample, consisting of recovered coarse-grains (CG), recrystallized fine-grains (FGs) and un-recrystallized ultrafine-grains (UFGs), possesses higher yield strength (YS) of ∼965 MPa, ultimate tensile strength (UTS) of ∼1680 MPa and uniform elongation (UEL) of ∼45 % when compared to the fully-recrystallized HS-740 sample at liquid nitrogen temperature (LNT). The difference in YS is primarily caused by the grain boundary and dislocation strengthening of UFGs, whereas the higher ductility of the HS-630 sample is associated with the hierarchical activation of transformation- and twinning-induced plasticity (TRIP and TWIP) effects, and compatible strain partitioning between heterogeneous domains. The dual-heterogeneity results in different critical stresses of ε-phase nucleation in heterogeneous domains, and promotes sustainable TRIP effect in CGs and the emergence of TWIP effect in UFGs with strain progressing. Moreover, the strain of the ductile transformed ε-phase is mainly accommodated by non-basal slip, which contributes to the strain hardening in the later deformation stage. Furthermore, the higher cryogenic impact toughness of the HS-630 sample can be attributed to the synergistic effects of the fracture mode, the transformation characteristics, and the heterogeneous strain partitioning.

Achieving high strength and superior wear‐resistant properties in TiH2 matrix reinforced with graphene nanoplates

In this work, low‐cost TiC/Ti composites with high strength‐ductility and superior abrasive resistance were fabricated using hydrogenation‐dehydrogenation (HDH) powder and graphene nanoplates as raw materials via spark plasma sintering (SPS) and hot rolling (HR) processes. Effects of in‐situ TiC contents on the microstructure, mechanical properties and wear behavior of the TiC/Ti composites were investigated. The results indicate that the microstructure after HR is equiaxial α‐Ti grain with random orientation. The TiC/Ti composites exhibit higher strength compared to pure Ti matrix after HR. The ultimate tensile strength of the 1.82vol% TiC/Ti composite is 1059 MPa, which represents a 49.3% increase compared to pure Ti. The coefficient of friction of the TiC/Ti composites decreases from 0.51 to 0.43 with an increase in TiC contents. The improvement of strength is attributed to refinement strengthening, dislocation strengthening and TiC load transfer. In addition, the increase of TiC contents will reduce the friction coefficient of the composites, thereby improving the wear resistance of the composites. The paper proposes a cost‐effective method with good prospects for industrial applications to improve the mechanical properties and wear‐resistant properties of the titanium alloys.This article is protected by copyright. All rights reserved.