C对CoFe_(2)NiV_(0.5)Mo_(0.2)高熵合金结构和力学性能的影响

Effect of C on Microstructure and Mechanical Properties of CoFe_(2)NiV_(0.5)Mo_(0.2) High Entropy Alloy

研究添加0%~10%(原子分数,下同)C对CoFe_(2)NiV_(0.5)Mo_(0.2)高熵合金显微组织、相结构和室温力学性能的影响。研究结果表明,随着C含量的增加,合金的微观组织由单一面心立方结构(FCC)转变为FCC基体+V 8C 7碳化物纤维的共晶组织,再转变为FCC基体+粗大V 8C 7+针状MoC组织,在转变过程中合金的压缩屈服强度明显提升,并保持较高的塑性。其中添加6%C时,合金的屈服强度和硬度可达到900 MPa、270HV。研究结果显示,以C为代表的小原子半径元素可以作为间隙固溶元素或与金属元素相结合形成碳化物第二相来提高FCC结构高熵合金的强度,改善合金的综合力学性能。

Effects of the addition of C with different molar fraction(0%—10%)on microstructure,phase structure and mechanical properties at room temperature of the CoFe_(2)NiV_(0.5)Mo_(0.2)high entropy alloy were investigated.The results show that with the increase of C content,the microstructure of alloy changed from a single face centered cubic structure(FCC)to eutectic structure(FCC matrix+V 8C 7 carbide fiber)and then to(FCC matrix+coarse V 8C 7+acicular MoC).The compressive yield strength of the alloy was improved significantly and remained good ductility simultaneously.When C content is 6%,the yield strength and hardness of the alloy can reach 900 MPa and 270HV respectively.The research results show that elements with small atomic radius represented by C can solubilize as interstitial element or combined with metal element to form carbide second phase,which can improve the FCC-structured high entropy alloy strength,thus optimizing its comprehensive mechanical properties.