Relationship between the unique microstructures and behaviors of high-entropy alloys

High-entropy alloys(HEAs),which were introduced as a pioneering concept in 2004,have captured the keen interest of nu-merous researchers.Entropy,in this context,can be perceived as representing disorder and randomness.By contrast,elemental composi-tions within alloy systems occupy specific structural sites in space,a concept referred to as structure.In accordance with Shannon entropy,structure is analogous to information.Generally,the arrangement of atoms within a material,termed its structure,plays a pivotal role in dictating its properties.In addition to expanding the array of options for alloy composites,HEAs afford ample opportunities for diverse structural designs.The profound influence of distinct structural features on the exceptional behaviors of alloys is underscored by numer-ous examples.These features include remarkably high fracture strength with excellent ductility,antiballistic capability,exceptional radi-ation resistance,and corrosion resistance.In this paper,we delve into various unique material structures and properties while elucidating the intricate relationship between structure and performance.

Microstructures and micromechanical behaviors of high -entropy alloys investigated by synchrotron X-ray and neutron diffraction techniques: A review

High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Extensive studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural materials.Synchrotron X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on materials.Recently,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation processes.In this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are discussed.The factors that influence the deformation mechanisms of HEAs are also outlined.This review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress changes.Perspectives on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed.

Microstructures,corrosion behavior and mechanical properties of as-cast Mg-6Zn-2X(Fe/Cu/Ni)alloys for plugging tool applications

Mg-6Zn-2X(Fe/Cu/Ni)alloys were prepared through semi-continuous casting,with the aim of identifying a degradable magnesium(Mg)alloy suitable for use in fracturing balls.A comparative analysis was conducted to assess the impacts of adding Cu and Ni,which result in finer grains and the formation of galvanic corrosion sites.Scanner electronic microscopy examination revealed that precipitated phases concentrated at grain boundaries,forming a semi-continuous network structure that facilitated corrosion penetration in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Pitting corrosion was observed in Mg-6Zn-2Fe,while galvanic corrosion was identified as the primary mechanism in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Among the tests,the Mg-6Zn-2Ni alloy exhibited the highest corrosion rate(approximately 932.9 mm/a)due to its significant potential difference.Mechanical testing showed that Mg-6Zn-2Ni alloy possessed suitable ultimate compressive strength,making it a potential candidate material for degradable fracturing balls,effectively addressing the challenges of balancing strength and degradation rate in fracturing applications.

Finite Element Simulations on Failure Behaviors of Granular Materials with Microstructures Using a Micromechanics-Based Cosserat Elastoplastic Model

This paper presents a micromechanics-based Cosserat continuum model for microstructured granular materials.By utilizing this model,the macroscopic constitutive parameters of granular materials with different microstructures are expressed as sums of microstructural information.The microstructures under consideration can be classified into three categories:a medium-dense microstructure,a dense microstructure consisting of one-sized particles,and a dense microstructure consisting of two-sized particles.Subsequently,the Cosserat elastoplastic model,along with its finite element formulation,is derived using the extended Drucker-Prager yield criteria.To investigate failure behaviors,numerical simulations of granular materials with different microstructures are conducted using the ABAQUS User Element(UEL)interface.It demonstrates the capacity of the proposed model to simulate the phenomena of strain-softening and strain localization.The study investigates the influence of microscopic parameters,including contact stiffness parameters and characteristic length,on the failure behaviors of granularmaterials withmicrostructures.Additionally,the study examines themesh independence of the presented model and establishes its relationship with the characteristic length.A comparison is made between finite element simulations and discrete element simulations for a medium-dense microstructure,revealing a good agreement in results during the elastic stage.Somemacroscopic parameters describing plasticity are shown to be partially related to microscopic factors such as confining pressure and size of the representative volume element.

Elliptical vibration chiseling:a novel process for texturing ultra-high-aspect-ratio microstructures on the metallic surface

High-aspect-ratio metallic surface microstructures are increasingly demanded in breakthrough applications,such as high-performance heat transfer enhancement and surface plasmon devices.However,the fast and cost-effective fabrication of high-aspect-ratio microstructures on metallic surfaces remains challenging for existing techniques.This study proposes a novel cutting-based process,namely elliptical vibration chiseling(EV-chiseling),for the high-efficiency texturing of surface microstructures with an ultrahigh aspect ratio.Unlike conventional cutting,EV-chiseling superimposes a microscale EV on a backward-moving tool.The tool chisels into the material in each vibration cycle to generate an upright chip with a high aspect ratio through material deformation.Thanks to the tool’s backward movement,the chip is left on the material surface to form a microstructure rather than falling off.Since one microstructure is generated in one vibration cycle,the process can be highly efficient using ultrafast(>1 kHz)tool vibration.A finite element analysis model is established to explore the process mechanics of EV-chiseling.Next,a mechanistic model of the microstructured surface generation is developed to describe the microstructures’aspect ratio dependency on the process parameters.Then,surface texturing tests are performed on copper to verify the efficacy of EV-chiseling.Uniformed micro ribs with a spacing of 1–10μm and an aspect ratio of 2–5 have been successfully textured on copper.Compared with the conventional EV-cutting that uses a forward-moving tool,EV-chiseling can improve the aspect ratio of textured microstructure by up to 40 times.The experimental results also verify the accuracy of the developed surface generation model of microstructures.Finally,the effects of elliptical trajectory,depth of cut,tool shape,and tool edge radius on the surface generation of micro ribs have been discussed.

Tuning microstructures of TC4 ELI to improve explosion resistance

A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion resistance.However,there is limited investigation on tuning microstructures of TC4 ELI to improve explosion resistance.Moreover,the current challenge is quantifying microstructural changes'effects on explosion resistance and incorporating microstructural changes into finite element models.This work aims to tune microstructures to improve explosion resistance and elucidate their anti-explosion mechanism,and find a suitable method to incorporate microstructural changes into finite element models.In this work,we systematically study the deformation and failure characteristics of TC4 ELI plates with varying microstructures using an air explosion test and LS-DYNA finite element modeling.The Johnson-Cook(JC)constitutive parameters are used to quantify the effects of microstructural changes on explosion resistance and incorporate microstructural changes into finite element models.Because of the heat treatment,one plate has equiaxed microstructure and the other has bimodal microstructure.The convex of the plate after the explosion has a quadratic relationship with the charge mass,and the simulation results demonstrate high reliability,with the error less than 17.5%.Therefore,it is feasible to obtain corresponding JC constitutive parameters based on the differences in microstructures and mechanical properties and characterize the effects of microstructural changes on explosion resistance.The bimodal target exhibits excellent deformation resistance.The response of bimodal microstructure to the shock wave may be more intense under explosive loading.The well-coordinated structure of the bimodal target enhances its resistance to deformation.

Electromagnetic responses on microstructures of duplex stainless steels based on 3D cellular and electromagnetic sensor finite element models

Microstructures determine mechanical properties of steels,but in actual steel product process it is difficult to accurately control the microstructure to meet the requirements.General microstructure characterization methods are time consuming and results are not rep-resentative for overall quality level as only a fraction of steel sample was selected to be examined.In this paper,a macro and micro coupled 3D model was developed for nondestructively characterization of steel microstructures.For electromagnetic signals analysis,the relative permeability value computed by the micro cellular model can be used in the macro electromagnetic sensor model.The effects of different microstructure components on the relative permeability of duplex stainless steel(grain size,phase fraction,and phase distribu-tion)were discussed.The output inductance of an electromagnetic sensor was determined by relative permeability values and can be val-idated experimentally.The findings indicate that the inductance value of an electromagnetic sensor at low frequency can distinguish dif-ferent microstructures.This method can be applied to real-time on-line characterize steel microstructures in process of steel rolling.

Characteristics and distribution of microstructures in high pressure die cast alloys with X-ray microtomography:A review

Al and Mg alloy high pressure die castings(HPDC)are increasingly used in automotive industries.The microstructures in the castings have decisive effect on the casting mechanical properties,in which the microstructure characteristics are fundamental for the investigation of the microstructure-property relation.During the past decade,the microstructure characteristics of HPDC Al and Mg alloys,especially micro-pores andα-Fe,have been investigated from two-dimensional(2D)to threedimensional with X-ray micro-computed tomography(μ-CT).This paper provides an overview of the current understanding regarding the 3D characteristics and formation mechanisms of microstructures in HPDC alloys,their spatial distributions,and the impact on mechanical properties.Additionally,it outlines future research directions for the formation and control of heterogeneous microstructures in HPDC alloys.

Topology Optimization of Metamaterial Microstructures for Negative Poisson’s Ratio under Large Deformation Using a Gradient-Free Method

Negative Poisson’s ratio(NPR)metamaterials are attractive for their unique mechanical behaviors and potential applications in deformation control and energy absorption.However,when subjected to significant stretching,NPR metamaterials designed under small strain assumption may experience a rapid degradation in NPR performance.To address this issue,this study aims to design metamaterials maintaining a targeted NPR under large deformation by taking advantage of the geometry nonlinearity mechanism.A representative periodic unit cell is modeled considering geometry nonlinearity,and its topology is designed using a gradient-free method.The unit cell microstructural topologies are described with the material-field series-expansion(MFSE)method.The MFSE method assumes spatial correlation of the material distribution,which greatly reduces the number of required design variables.To conveniently design metamaterials with desired NPR under large deformation,we propose a two-stage gradient-free metamaterial topology optimization method,which fully takes advantage of the dimension reduction benefits of the MFSE method and the Kriging surrogate model technique.Initially,we use homogenization to find a preliminary NPR design under a small deformation assumption.In the second stage,we begin with this preliminary design and minimize deviations in NPR from a targeted value under large deformation.Using this strategy and solution technique,we successfully obtain a group of NPR metamaterials that can sustain different desired NPRs in the range of[−0.8,−0.1]under uniaxial stretching up to 20% strain.Furthermore,typical microstructure designs are fabricated and tested through experiments.The experimental results show good consistency with our numerical results,demonstrating the effectiveness of the present gradientfree NPR metamaterial design strategy.

Solid polymer electrolytes in all-solid-state lithium metal batteries:From microstructures to properties

All-solid-state lithium(Li)metal batteries(ASSLMBs)are considered one of the most promising secondary batteries due to their high theoretical capacity and high safety performance.However,low room-temperature ionic conductivity and poor interfacial stability are two key factors affecting the practical application of ASSLMBs,and our understanding of the mechanisms behind these key problems from microscopic perspective is still limited.In this review,the mechanisms and advanced characterization techniques of ASSLMBs are summarized to correlate the microstructures and properties.Firstly,we summarize the challenges faced by solid polymer electrolytes(SPEs)in ASSLMBs,such as the low roomtemperature ionic conductivity and the poor interfacial stability.Secondly,several typical improvement methods of polymer ASSLMBs are discussed,including composite SPEs,ultra-thin SPEs,SPEs surface modification and Li anode surface modification.Finally,we conclude the characterizations for correlating the microstructures and the properties of SPEs,with emphasis on the use of emerging advanced techniques(e.g.,cryo-transmission electron microscopy)for in-depth analyzing ASSLMBs.The influence of the microstructures on the properties is very important.Until now,it has been difficult for us to understand the microstructures of batteries.However,some recent studies have demonstrated that we have a better understanding of the microstructures of batteries.Then we suggest that in situ characterization,nondestructive characterization and sub-angstrom resolution are the key technologies to help us further understand the batteries'microstructures and promote the development of batteries.And potential investigations to understand the microstructures evolution and the batteries behaviors are also prospected to expect further reasonable theoretical guidance for the design of ASSLMBs with ideal performance.

Tailor-made microstructures lead to high-performance robust PEO membrane for CO_(2)capture via green fabrication technique

Emerging excessive greenhouse gas emissions pose great threats to the ecosystem,which thus requires efficient CO_(2)capture to mitigate the disastrous issue.In this report,large molecular size bisphenol A ethoxylate diacrylate(BPA)was employed to crosslink poly(ethylene glycol)methyl ether acrylate(PEGMEA)via the green and rapid UV polymerization strategy.The microstructure of such-prepared membrane could be conveniently tailored by tuning the ratio of the two prepolymers,aiming at obtaining the optimized microstructures with suitable mesh size and PEO sol content,which was approved by a novel low-field nuclear magnetic resonance technique.The optimum membrane overcomes the tradeoff challenge:dense microstructures lower the gas permeability while loose microstructures lower high-pressure-resistance capacity,realizing a high CO_(2)permeability of 1711 Barrer and 100-h long-term running stability under 15 atm.The proposed membrane fabrication approach,hence,opens a novel gate for developing high-performance robust membranes for CO_(2)capture.

Effect of Ti content on microstructures and mechanical properties of cast Al-2Li-2Cu-0.5Mg alloy

Ti is regarded as one of the promising grain refiners in cast Al-Li-Cu alloys,but few research works have been done on its independent role.In this study,the effect of Ti on the microstructure evolution and mechanical properties of cast Al-2Li-2Cu-0.5Mg base alloy was investigated.The results revealed that the grains can be prominently refined with the increase of Ti addition.After adding Ti,high density TiB_(2)-Al_(3)Ti composite particles with a low lattice misfit form as heterogeneous nucleation sites for the α-Al matrix.δ’(Al3Li) and T_(1)(Al_(2)CuLi) precipitates that provide enhanced strength are dominated in the alloys after T6 aging treatment.The average size of both δ’ and half-width of δ’-precipitation free zone(PFZ) decreases gradually with the increase of Ti content.This is because the higher binding energy between Ti atoms and vacancies limits the diffusion efficiency of Li atoms,and thus results in a higher ductility.Additionally,no nano-sized Al_(3)Ti or core-shell structure of Al_(3)(Li,Ti) particles are found.The tensile property test results indicate that the Al-2Li-2Cu-0.5Mg alloy achieves optimal properties after aging at 175 °C for 32 h when 0.15wt.% Ti is added.It exhibits a yield strength of 352±5 MPa,an ultimate tensile strength of 423±6 MPa,and an elongation of(3±0.4)%.These findings are expected to offer a reliable theoretical guidance for the industrial composition design of the Al-Li-Cu series cast alloys.

Effects of Electric and Magnetic Treatments on Microstructures of Solid Metals: A Review

An external electric or magnetic field can transfer high-intensity energy directly to the electronic scale of materials,and change the spin,energy level arrangement and trajectory of electrons.These changes produce tremendous and profound impacts on the microstructure and mechanical properties of metal materials,which may be impos-sible with traditional technologies.This paper reviews the effects of electric or magnetic field on the microstruc-tures of solid metals including phase transformation,precipitation,recrystallization,dislocations and so on.Based on the existing research results,the mechanisms of these effects have been discussed.Additionally,some typical applications of electric and magnetic treatments on solid metals have been described and the challenges in this field have also been discussed.

The Effects of WC on the Microstructures and Wear Resistance of FeCoCrNiB_(0.2) High Entropy Alloy

To improve the wear resistance of the FeCoCrNiB_(0.2)high entropy alloy(HEA),the FeCoCrNiB_(0.2)(WC_(0))and FeCoCrNiB_(0.2)+20wt%WC(WC_(20))HEA coatings were prepared on Q235 steel by laser cladding(LC).The microstructure,hardness,and tribometer of the HEA coatings were investigated using scanning electron microscopy with spectroscopy(SEM/EDS),X-ray diffraction(XRD),vickers microhardness tester,and pin-on-disc tribometer,respectively.The experimental results show that the WC0HEA coating comprises a simple BCC phase mixed with an M_(2)B phase.Adding 20wt%WC,the WC_(20)HEA coating is composed of a simple BCC phase mixed with the Cr_(23)C_(6)carbide phase.The microstructure of the WC_(20)HEA coating is simple,which consists of equiaxed grain and dendritic.The microhardness also increases from 625.5HV to 806.0HV,and the wear mass loss correspondingly decreases from 30.9 to 14.9 mg.W and C atoms formed by WC dissolution are mainly dissolved in the BCC phase,which leads to the solution strengthening effect.Besides,Cr_(23)C_(6)carbides inhibit the growth of the grains,play the role of fine-grain strengthening,and further improve the hardness and wear resistance of the HEA coating.

Influences of oxide content and sintering temperature on microstructures and mechanical properties of intragranular-oxide strengthened iron alloys prepared by spark plasma sintering

How to increase strength without sacrificing ductility has been developed as a key goal in the manufacture of high-performance metals or alloys. Herein, the double-nanophase intragranular yttrium oxide dispersion strengthened iron alloy with high strength and appreciable ductility was fabricated by solution combustion route and subsequent spark plasma sintering, and the influences of yttrium oxide content and sintering temperature on microstructures and mechanical properties were investigated. The results show at the same sintering temperature,with the increase of yttrium oxide content, the relative density of the sintered alloy decreases and the strength increases. For Fe–2wt%Y_(2)O_(3)alloy, as the sintering temperature increases gradually, the compressive strength decreases, while the strain-to-failure increases. The Fe–2wt%Y_(2)O_(3)alloy with 15.5 nm Y_(2)O_(3)particles uniformly distributed into the 147.5 nm iron grain interior sintered at 650℃ presents a high ultimate compressive strength of 1.86 GPa and large strain-to-failure of 29%. The grain boundary strengthening and intragranular second-phase particle dispersion strengthening are the main dominant mechanisms to enhance the mechanical properties of the alloy.

Wire arc additive manufacturing of a heat-resistant Al-Cu-Ag-Sc alloy:microstructures and high-temperature mechanical properties

With a high energy efficiency,low geometric limitation,and low cracking susceptivity to cracks,wire arc additive manufacturing(WAAM)has become an ideal substitute for casting in the manufacturing of load-bearing high strength aluminum components in aerospace industry.Recently,in scientific researches,the room temperature mechanical performance of additive manufactured high strength aluminum alloys has been continuously broken through,and proves these alloys can achieve comparable or even higher properties than the forged counterpart.Since the aluminum components for aerospace usage experience high-low temperature cycling due to the absence of atmosphere protection,the high temperature performances of additive manufactured high strength aluminum alloys are also important.However,few research focuses on that.A special 2319Ag Sc with 0.4 wt.%Ag and 0.2 wt.%Sc addition designed for high temperature application is deposited successfully via cold metal transfer(CMT)based on WAAM.The microstructures and high temperature tensile properties are investigated.The results show that the as-deposited 2319Ag Sc alloy presents an alternate distribution of columnar grains and equiaxed grains with no significant textures.Main second phases are Al_(2)Cu and Al3Sc,while co-growth of Al_(2)Cu and bulk Al_(3)Sc is found on the grain boundary.During manufacturing,nanoscale Al_(2)Cu can precipitate out from the matrix.Ag and Mg form nano-scaleΩphase on the Al_(2)Cu precipitates.At 260℃,average yield strengths in the horizontal direction and vertical direction are 87 MPa±2 MPa,87 MPa±4 MPa,while average ultimate tensile strengths are 140 MPa±7 MPa,141 MPa±11 MPa,and average elongations are 11.0%±2.5%,13.5%±3.0%.Anisotropy in different directions is weak.

Types and microstructures of pores in shales of the Ordovician Wulalike Formation at the western margin of the Ordos Basin, China

Shale samples from the Ordovician Wulalike Formation at the western margin of the Ordos Basin are studied to define the types, microstructures and connectivity of pores as well as the relationships between the pore structures and gas content of the samples by using experimental techniques such as high-resolution field emission scanning electron microscopy (FESEM), mercury injection capillary pressure (MICP), low-temperature nitrogen adsorption (LTNA), CO_(2) adsorption, and focused ion beam scanning electron microscopy (FIB-SEM). The results show that the shale has 10 different lithofacies, typical mixed sedimentary characteristics, and poorly developed pores. The reservoir space mainly consists of intercrystalline pores, dissolution pores, intergranular pores, and micro-fissures, with organic pores occasionally visible. The pore size is mostly within 0.4–250 nm range but dominated by micropores and mesopores less than 20 nm, with pore numbers peaking at pore sizes of 0.5 nm, 0.6 nm, 0.82 nm, 3 nm, and 10 nm, respectively. The pores are poorly connected and macropores are rarely seen, which may explain the low porosity and low permeability of the samples. Samples with high content of organic matter and felsic minerals are potential reservoirs for oil and gas with their favorable physical properties and high connectivity. The pores less than 5 nm contribute significantly to the specific surface area and serve as important storage space for adsorbed gas.

Microstructures of Developed Composite Graphite-Resin Electrodes

This paper focuses on the effects of compaction on the microstructure of graphite-resin electrochemical treatment electrodes. This was with a view to understanding the relationships between forming parameters and some performance-limiting structural parameters of the electrode. Graphite resin electrodes were developed from graphite rods reclaimed from primary cells. The rods were crushed to powder of various particle sizes and compressed into the graphite-resin electrodes. The microstructure of the graphite electrode was observed, effects of compaction force and particles sizes distribution on the microstructure of the electrodes were observed. SEM/EDX revealed that there is a lack of homogeneity in the distribution of micro-constituents, with compositional variations differing at the various spots. However, there is a prevalence of carbon and oxygen at almost all the spots. This tends to confirm the even distribution of the elements throughout the material. The pores in the electrodes were noticed to be uniformly sized and permeate throughout the entire structure of the electrode. These pores serve to increase the surface area of these electrodes and promote the adsorption of environmental pollutants.

聚氨酯泡沫注浆修复材料泡孔结构特征及抗压性能研究进展

聚氨酯泡沫(PUF)注浆修复材料以轻质高强、快凝高膨胀等优势,在基础设施修复加固领域得到了广泛的应用。抗压性能是工程修复材料十分重要的力学指标之一,而材料的微观结构对其宏观力学行为有决定性影响。近年来,国内外专家学者对PUF注浆修复材料的微观结构特性和抗压性能进行了大量研究,但尚未见到系统性总结。本文介绍了PUF注浆修复材料的定义及反应过程,综述了其微观泡孔结构特性、压缩应力-应变关系和本构模型,从宏微观角度讨论了其变形和破坏机理,总结了密度、试件尺寸、应变率和特殊环境工况对压缩性能的影响机理及规律,最后展望了PUF注浆修复材料未来的研究方向。

CoCrFeNiW_(x)高熵合金在室温及900℃下的摩擦磨损性能

采用真空电弧熔炼技术制备了CoCrFeNiW_(x)(x=0.25、0.5、0.75及1.0)系列高熵合金,研究了W元素含量对合金晶体结构、显微组织、力学性能以及室温与900℃摩擦学性能的影响.结果表明:合金中W含量较低时形成单相面心立方(FCC)固溶体,W含量较高时会促进金属间化合物μ相的形成,随着W含量提升,合金显微组织由FCC胞状树枝晶(x=0.25)转变为FCC树枝晶及晶间层片状(FCC+μ)共晶组织(x=0.5、0.75),最后转变为FCC基体上分布的粗大树枝状μ相(x=1.0).由于W元素的固溶强化及原位生成金属间化合物μ相的第二相强化作用,使合金的强度和硬度等力学性能显著增加的同时塑性降低.在试验载荷为10 N,滑动速度0.3 m/s的测试条件下,CoCrFeNiW_(x)系列高熵合金与Si_(3)N_(4)陶瓷球配副时的球-盘摩擦试验结果表明:W元素的添加显著改善了合金的室温耐磨性,但对摩擦系数的影响较小;而900℃摩擦时,摩擦表面形成的多元复合氧化物摩擦釉质层具有良好的减摩抗磨作用,特别是W元素氧化产生的WO_(3)显著降低了摩擦系数,从而显著提升了合金的高温摩擦磨损性能.本文中研究的系列高熵合金中,CoCrFeNiW_(0.75)高熵合金室温下的屈服强度为863 MPa,抗压强度达1 250 MPa,900℃仍能保持446 HV的硬度,并在室温及900℃下均具有良好的摩擦磨损性能,具有良好的工程应用前景.