激光熔覆FeCoCrNiNb高熵合金涂层组织及力学性能

Microstructure and mechanical properties of laser cladding FeCoCrNiNb high entropy alloy coating

摘要:

采用激光熔覆技术在304不锈钢表面制备了FeCrCoNi、FeCrCoNiNb等摩尔比高熵合金熔覆层,研究了Nb元素对熔覆层组织及性能的影响。采用XRD、SEM、EDS、纳米压痕测试和王府干滑动摩擦磨损实验等方法,纤细分析了两种高熵合金熔覆层线组成、组织演变、纳米硬度及磨损行为及磨损机理。结果表明：FeCrCoNiNb高熵合金熔覆层相组成为FCC固溶体及富Nb-Laves相。FeCrCoNiNb熔覆层的纳米硬度(H)、弹性模量(H)、H/E和H3/E2分别为6.066GPa、231.54GPa、0.0262和0.0042,远高于FeCrCoNi熔覆层的3.456GPa、209.48GPa、0.0165和0.00094。随着纳米硬度的增加,FeCrCoNiNb熔覆层的摩擦系数和比磨损率也随之降低,分别为0.519和2.54×10_-6^mm₃^/N.m。综上所述,FeCrCoNiNb高熵合金熔覆层具有良好的纳米硬度和磨损性能。

Abstract:

A FeCrCoNiNb high entropy alloy (HEA) coating was deposited by laser cladding, aiming at studying the influence of Nb addition on hardness and wear resistance. The formed phases, microstructural evolution, nano-hardness and wear behavior of the FeCrCoNiNb HEA coating was clarified by using XRD, SEM, nano-hardness measurement and friction-wear measurement. The results showed that the FeCrCoNiNb high-entropy alloy coating were composed by FCC solid solution and Nb-Laves phase. The nano-hardness (H), elastic modulus (H), H/E and H3/E2 of FeCrCoNiNb coating were 6.066GPa, 231.54GPa, 0.0262 and 0.0042, respectively. Which were much higher than FeCrCoNi coating of 3.456GPa, 209.48GPa, 0.0165 and 0.00094. With the increased of nano-hardness, the friction coefficient and specific wear rate of FeCrCoNiNb coating also decreased, which were 0.519 and 2.54×10-6mm3/N.m, respectively. The addition of Nb can effectively improve the nano-hardness and wear resistance of FeCrCoNi high-entropy alloy coating.