Ti_(0.5)AlCoFeNiCr_x高熵合金的微观组织结构与力学性能

Microstructures and Mechanical Properties of Ti_(0.5)AlCoFeNiCr_x High-entropy Alloys

通过XRD分析、SEM观察和压缩实验研究了不同Cr含量对Ti0.5AlCoFeNiCrx(x为摩尔比,x=0,0.5,1,1.5,2,3)高熵合金微观组织结构与力学性能的影响。结果表明:当合金不含Cr时,呈现单一的体心立方结构;当加入Cr元素后,出现了另一种富Cr的体心立方相。随着Cr含量的增加,组织从树枝晶逐渐转变到亚共晶、共晶和过共晶组织,表明Cr能促使合金发生共晶反应。适量的Cr元素能显著提高合金的压缩力学性能,其中Ti0.5AlCoFeNiCr0.5合金具有最好的压缩强度和塑性。

Influence of different Cr contents on microstructures and mechanical properties of Ti_（0.5）AlCoFeNiCr_x（x values in molar radio,x=0,0.5,1,1.5,2,3） high-entropy alloys were studied by X-ray diffractometry（XRD）,scanning electron microscopy（SEM） and mechanical tests.The results show that the alloy without Cr exhibits a single BCC structure;another Cr-rich BCC phase is found in the alloys with addition of Cr element.With increasing Cr content,the microstructures change from dendrite to hypoeutectic,eutectic and hypereutectic microstructures,indicating that Cr can promote the eutectic reaction.Proper Cr element can enhance compression properties of alloys obviously,and the Ti_（0.5）AlCoFeNiCr_（0.5） alloy exhibits the best compression strength and plasticity.