Mo元素对激光熔覆AlCoCrFeNiMo x 高熵合金涂层组织性能的影响

Effect of Mo on Microstructure and Properties of AlCoCrFeNiMo x High Entropy Alloy Coatings Prepared by Laser Cladding

摘要:

采用激光熔覆的方法制备AlCoCrFeNiMo_x高熵合金涂层。研究Mo元素含量对涂层微观结构、硬度及耐腐蚀性的影响。结果表明，随着Mo含量的增加，微观组织从富(Al, Ni)的体心立方（bcc）相和富(Mo-Cr-Fe)的σ相，转变为富(Fe, Ni)的bcc相、富(Mo-Cr-Fe)的σ相、富(Al-Fe-Mo)的σ相与少量AlN相。此外，涂层的显微硬度（HV₁）从6154.4 MPa增加到10652.6 MPa。随着Mo含量的添加，涂层在3.5%（质量分数）氯化钠溶液中的自腐蚀电位升高，当Mo含量为x=1.0时，涂层的耐腐蚀性能最好。

Abstract:

AlCoCrFeNiMo_x (x=0, 0.5, 1.0, 1.5, 2.0) high entropy alloy (HEA) coatings were prepared by laser cladding method. The effect of Mo content on the microstructure, hardness, and corrosion resistance of the coatings was studied. Results show that with increasing the Mo content, the microstructure is changed from (Al, Ni)-rich body-centered cubic (bcc) phase+(Mo-Cr-Fe)-rich σ phase into (Fe, Ni)-rich bcc phase+(Mo-Cr-Fe)-rich σ phase+(Al-Fe-Mo)-rich σ phase+a little AlN (aluminum nitride). Additionally, the coating hardness (HV₁) is increased from 6514.4 MPa to 10652.6 MPa. With increasing the Mo addition, the self-corrosion potential of the coating in 3.5wt% NaCl solution is also increased. The coating presents the optimal corrosion resistance at x=1.0.