ABSTRACT

FeNiCoCrNb_x (x: molar ratio, x = 0, 0.1, 0.2, 0.3) high entropy alloy coatings (HEACs) were fabricated on 316 stainless steel (SS) by laser cladding (LC). Experimental results showed that the addition of Nb increased the lattice constant of FeNiCoCrNb high entropy alloy system. HEAC exhibited the transformation from columnar crystal at the interface to equiaxed crystal at the surface on the cross-sectional plane because of the change in the temperature gradient (G) and solidification rate (R). When x = 0.3, lamellar Laves phases appeared in ID. The microhardness of the four HEACs was 1.78, 2.19, 2.30 and 2.37 times that of 316 SS. The HEAC with x = 0.3 as well as 316 SS exhibited typical p-type semiconductor characteristics, which showed excellent corrosion resistance as indicated by the lowest $I_{\mathrm{corr}}$ of 2.46 × 10⁻⁹ A cm⁻² and a larger passivation region with 2 times that of 316 SS.

摘要

 通过激光熔覆 (LC) 在 316 不锈钢 (SS) 上制备FeNiCoCrNb _x ( x : 摩尔比, x = 0, 0.1, 0.2, 0.3) 高熵合金涂层 (HEAC)。实验结果表明，Nb的加入提高了FeNiCoCrNb高熵合金体系的晶格常数。由于温度梯度（G）和凝固速率（R）的变化，HEAC在横截面上表现出从界面处的柱状晶体到表面处的等轴晶体的转变。当x  = 0.3 时，层状 Laves 相出现在 ID 中。四种 HEAC 的显微硬度分别是 316 SS 的 1.78、2.19、2.30 和 2.37 倍。带有x的 HEAC = 0.3 和 316 SS 表现出典型的 p 型半导体特性，表现出优异的耐腐蚀性，如最低${我}_{\mathrm{更正}}$2.46 × 10 ^-9 A cm ^-2和更大的钝化区域，是 316 SS 的 2 倍。