激光熔覆CoCrFeNiTi_(x)高熵合金涂层的组织与性能

Microstructure and properties of CoCrFeNiTi_(x) high-entropy alloy coating by laser cladding

为了探究Ti元素对高熵合金涂层组织与性能的影响,利用激光熔覆技术在Q235基体表面制备CoCrFeNiTi_(x)(x=0.4、0.6、0.8、1.0)涂层,采用XRD、SEM、EDS等方法分析涂层的相结构和显微组织,用显微维氏硬度计和摩擦磨损试验机测试涂层的硬度和耐磨性。结果表明:涂层的显微组织由胞状晶向树枝晶转变,相结构由BCC和FCC组成。涂层显微硬度的提高归因于固溶强化和细晶强化的共同作用,涂层的磨损机理主要为磨粒磨损和黏着磨损,并伴有轻微氧化。当x=0.8时,涂层的硬度(HV)可达524,磨痕较为平整,耐磨性优异。

In order to study the effects of Ti element on the microstructure and properties of high-entropy alloy coatings,CoCrFeNiTi_(x)(x=0.4,0.6,0.8,1.0)coatings were prepared on the surface of Q235 substrate using laser cladding technology,and the phase structure and microstructure of the coatings were analysed by XRD,SEM,EDS,etc.,and the hardness and wear resistance of the coatings were tested by micro-Vickers hardness tester and friction and wear tester.The results show that the microstructure of the coating changes from cellular crystal to dendritic crystal,and the phase structure consists of BCC and FCC.The increase in microhardness of the coatings is attributed to the combined effect of solid solution strengthening and fine crystal strengthening,and the wear mechanisms of the coatings are mainly abrasive wear and adhesive wear,accompanied by slight oxidation.When x=0.8,the hardness(HV)of the coating reaches 524,with relatively flat abrasive marks and excellent wear resistance.