摘要 Fe27Mn27Ni28Cr18高熵合金具有优异的耐腐蚀性和抗辐照性,但其屈服强度较低。为提高合金的强度,采用真空电弧熔炼炉制备了FeCrNiMnZrx(x=0,0.02,0.03,0.07)高熵合金,并对其组织及力学性能进行表征分析。研究结果表明:FeCrNiMn合金的铸态组织由富Ni、Mn的FCC基体和富Cr的片状BCC相组成。当添加相对含量x=0.02的Zr元素时,FeCrNiMnZr0.02合金中富Cr的BCC相呈短细条状或花边状,有少量小片状或短条状的Ni11Zr9化合物析出,合金强度和硬度同时升高,具有最佳的综合力学性能。随着Zr添加量的进一步增加,合金中富Cr的BCC相逐渐减少,而枝晶间析出的Ni11Zr9化合物量逐渐增多,形态也变为长链条状乃至完全网状,合金的屈服强度和硬度升高,但断后延伸率大幅下降。断口分析发现,随Zr含量增加,合金的断裂机制由以韧窝为主的韧性断裂逐渐转变为以解理台阶为主的脆性断裂。 Fe27Mn27Ni28Cr18high entropy alloy has excellent corrosion resistance and irradiation resistance,but low yield strength.The study is aimed to improve the strength of the alloy.FeCrNiMnZrx(x=0,0.02,0.03,0.07)high entropy alloy was prepared by using a vacuum arc melting furnace,and its microstructure and mechanical properties were characterized and analyzed.The results are as follows:The as cast microstructure of FeCrNiMn alloy consisted of FCC matrix rich in Ni and Mn and lamellar BCC phase rich in Cr.With the addition of x=0.02 Zr,the BCC phase rich in Cr in FeCrNiMnZr0.02alloy took the shape of short thin strip or lace,with a small amount of small flake or short strip Ni11Zr 9 compound precipitated,and the strength and hardness of the alloy increased at the same time,showing that it had the best comprehensive mechanical properties.With the further increase of Zr content,the amount of Cr rich BCC phase in the alloy gradually decreased while the amount of Ni11Zr9compound precipitated from dendrites increased gradually,and the morphology of Ni11Zr9compound changed into long chain or even complete network.The yield strength and hardness increased,but the elongation decreased significantly.The fracture analysis shows that with the increase of Zr content,the fracture mechanism of the alloy changed gradually from the ductile fracture dominated by dimples to the brittle fracture dominated by cleavage steps.
出处 《西安工业大学学报》 CAS 2021年第1期74-80,共7页 Journal of Xi’an Technological University
基金 国家自然科学基金(51671150)。
关键词 高熵合金 Ni 11 Zr 9 拉伸性能 显微硬度 断口分析 high entropy alloy Ni 11 Zr 9 tensile properties microhardness fracture analysis
