激光表面重熔对CoCrFeNiW0.5高熵合金组织及性能的影响

    Effects of Laser Surface Remelting on Microstructure and Properties of CoCrFeNiW0.5 High-entropy Alloy

    • 摘要: 采用真空氩弧熔炼制备了非等原子比CoCrFeNiW0.5 高熵合金并进行了激光表面重熔处理,系统研究了激光表面重熔对合金相组成、显微组织、硬度及摩擦磨损性能的影响。结果表明:铸态高熵合金的显微组织由枝晶FCC 相及枝晶间(FCC+μ)共晶组织组成,激光重熔后合金的共晶组织消失并且晶粒明显细化,金属间化合物μ 相以颗粒状分布在等轴FCC 的晶界上。与铸态合金相比,激光重熔后合金的硬度提升约17%,与Si3N4 陶瓷配副时的摩擦系数降低约7%,磨损率降低约75%,这主要归因于激光重熔过程引起的细晶强化、固溶强化,以及合金组织成分均匀性的提升。

       

      Abstract: Non-equiatomic CoCrFeNiW0.5 high entropy alloy (HEA) was prepared by vacuum arc melting followed by laser remelting treatment, the effects of laser remelting on the phase composition, microstructure, hardness and friction and wear properties of the alloy were systematically studied.The results show that the microstructure of as-cast HEA consists of dendritic FCC and interdendritic (FCC+μ)phase.After laser remelting, the eutectic structure of the alloy disappears and the grains are obviously refined, the intermetallic compound μ phase is distributed in the grain boundary of equiaxed FCC in granular form.Compared with the as-cast HEA, The remelted HEA exhibits an increase of about 17% in microhardness, a decrease of about 7%in friction coefficient and decrease of about 75%in wear rate, which is mainly due to the microstructure refinement strengthening, solid solution strengthening, and the improvement of the uniformity of the alloy microstructure and composition caused by the laser remelting process.

       

    /

    返回文章
    返回