Mo含量对FeCoCrNiMox高熵合金等离子喷焊层组织与性能的影响

目的 研究不同Mo元素添加量对FeCoCrNiMox(x=0、0.5、1、1.5)高熵合金等离子喷焊层组织和性能的影响，以期望获得一种高硬度、耐腐蚀的喷焊层，用于改善传统工模具表面防护与使用寿命的问题。方法 采用等离子喷焊技术在Q235A低碳钢表面制备了不同Mo含量的高熵合金喷焊层，通过X射线衍射仪(XRD)、光学显微镜(OM)、扫描电子显微镜(SEM)、能量色散X射线光谱仪(EDS)表征其微观组织与相结构，借助显微硬度计和电化学工作站对喷焊层的硬度和耐腐蚀性能进行测试。结果 随着Mo含量x从0逐渐增加到1.5，喷焊层的晶界胞状枝晶组织(枝晶内为白色富Mo相，枝晶间为灰色富Fe、Ni相)逐渐增加，合金微观组织变得细小;喷焊层的硬度由204.4HV0.2增加至706.8HV0.2;喷焊层在3.5%NaCl溶液中呈现出明显的钝化行为，腐蚀电位由?0.753 V增大到?0.412 V，腐蚀电流密度由1.23×10^?4 A/cm²减小到3.80×10^?6 A/cm²，点蚀电位由?0.642 V增大到?0.371 V，具有优异的耐腐蚀性能。结论 所设计的FeCoCrNiMox合金及相应的等离子喷焊工艺，满足对喷焊层高耐磨以及耐腐蚀性的要求，有望应用于传统工模具的表面防护与修复。

Effect of Mo Content on the Microstructure and Properties of High-entropy alloy Coatings Produced by Plasma Transferred Arc Welding

Plasma spray welding is a very important and rapidly developing method in surface modification technology. It can strengthen the surface properties without changing the matrix materials, such as improving the wear resistance, corrosion resistance, high temperature oxidation resistance and service life of materials. At the same time, as a new coating material, high entropy alloys (HEAs) has different performance characteristics from traditional coating materials because of its four effects:high entropy effect in thermodynamics, hysteresis diffusion effect in dynamics, lattice distortion effect in structure and cocktail effect in performance. The alloy can have high hardness, high wear resistance, high corrosion resistance and high interfacial compatibility at the same time. At the same time, the alloy elements can be optimized by phase composition prediction and phase diagram simulation, which has good research value. In this paper, FeCoCrNiMo high entropy alloy powder was used as coating material, and high entropy alloy plasma spray welding layer was prepared by plasma spray welding technology. The effects of different Mo content on the microstructure and corrosion resistance of the welding layer were studied.