Arsenic materials have attracted great attention due to their unique properties.However,research concerning iron-arsenic(Fe-As) alloys is very scarce due to the volatility of As at low temperature and the high melting...Arsenic materials have attracted great attention due to their unique properties.However,research concerning iron-arsenic(Fe-As) alloys is very scarce due to the volatility of As at low temperature and the high melting point of Fe.Herein,a new Fe-As alloy was obtained by mechanical alloying(MA) followed by vacuum hot-pressed sintering(VHPS).Moreover,a systematic study was carried out on the microstructural evolution,phase composition,leaching toxicity of As,and physical and mechanical properties of Fe-As alloys with varying weight fractions of As(20%,25%,30%,35%,45%,55%,65%,and 75%).The results showed that pre-alloyed metallic powders(PAMPs) have a fine grain size and specific supersaturated solid solution after MA,which could effectively improve the mechanical properties of Fe-As alloys by VHPS.A high density(> 7.350 g·cm^(-3)),low toxicity,and excellent mechanical properties could be obtained for FeAs alloys sintered via VHPS by adding an appropriate amount of As,which is more valuable than commercial Fe-As products.The Fe-25% As alloy with low toxicity and a relatively high density(7.635 g·cm^(-3)) provides an ultra-high compressive strength(1989.19 MPa),while the Fe-65% As alloy owns the maximum Vickers hardness(HVo.5 899.41).After leaching by the toxicity characteristic leaching procedure(TCLP),these alloys could still maintain good mechanical performance,and the strengthening mechanisms of Fe-As alloys before and after leaching were clarified.Changes in the grain size,micro structure,and phase distribution induced significant differences in the compressive strength and hardness.展开更多
A combined process of molten salt electro-deoxidation and vacuum hot-pressing sintering was proposed to prepare AlCrFeNiTi_(x) high-entropy alloy(HEA)-TiN ceramic coating composites on low-carbon steel surfaces,where ...A combined process of molten salt electro-deoxidation and vacuum hot-pressing sintering was proposed to prepare AlCrFeNiTi_(x) high-entropy alloy(HEA)-TiN ceramic coating composites on low-carbon steel surfaces,where nitrides were introduced from BN isolater between graphite mold and HEA powders.The effect of Ti content on the microstructure,ultimate tensile strength,hardness,and wear resistance of the composites was investigated,and the bonding mechanism was elucidated.Results demonstrate that the composites have excellent hardness and wear resistance.The hardness of composites is significantly increased with the increase in Ti content.The extremely high wear resistance is attributed to the extremely high melting point and high thermal hardness of TiN,which can effectively prevent oxidation deformation of the worn surface.展开更多
基金financially supported by the National Natural Science Foundation of China (No.52104406)the Natural Science Foundation of Hunan Province (No.2022JJ20074)+1 种基金the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No.52121004)the National Natural Science Foundation of China for Distinguished Young Scholars (No.51825403)。
文摘Arsenic materials have attracted great attention due to their unique properties.However,research concerning iron-arsenic(Fe-As) alloys is very scarce due to the volatility of As at low temperature and the high melting point of Fe.Herein,a new Fe-As alloy was obtained by mechanical alloying(MA) followed by vacuum hot-pressed sintering(VHPS).Moreover,a systematic study was carried out on the microstructural evolution,phase composition,leaching toxicity of As,and physical and mechanical properties of Fe-As alloys with varying weight fractions of As(20%,25%,30%,35%,45%,55%,65%,and 75%).The results showed that pre-alloyed metallic powders(PAMPs) have a fine grain size and specific supersaturated solid solution after MA,which could effectively improve the mechanical properties of Fe-As alloys by VHPS.A high density(> 7.350 g·cm^(-3)),low toxicity,and excellent mechanical properties could be obtained for FeAs alloys sintered via VHPS by adding an appropriate amount of As,which is more valuable than commercial Fe-As products.The Fe-25% As alloy with low toxicity and a relatively high density(7.635 g·cm^(-3)) provides an ultra-high compressive strength(1989.19 MPa),while the Fe-65% As alloy owns the maximum Vickers hardness(HVo.5 899.41).After leaching by the toxicity characteristic leaching procedure(TCLP),these alloys could still maintain good mechanical performance,and the strengthening mechanisms of Fe-As alloys before and after leaching were clarified.Changes in the grain size,micro structure,and phase distribution induced significant differences in the compressive strength and hardness.
基金National Natural Science Foundation of China(52174315)Youth Scholars Promotion Plan of North China University of Science and Technology(QNTJ202304)。
文摘A combined process of molten salt electro-deoxidation and vacuum hot-pressing sintering was proposed to prepare AlCrFeNiTi_(x) high-entropy alloy(HEA)-TiN ceramic coating composites on low-carbon steel surfaces,where nitrides were introduced from BN isolater between graphite mold and HEA powders.The effect of Ti content on the microstructure,ultimate tensile strength,hardness,and wear resistance of the composites was investigated,and the bonding mechanism was elucidated.Results demonstrate that the composites have excellent hardness and wear resistance.The hardness of composites is significantly increased with the increase in Ti content.The extremely high wear resistance is attributed to the extremely high melting point and high thermal hardness of TiN,which can effectively prevent oxidation deformation of the worn surface.
