Mo添加对Al19Fe20- x Co20- x Ni41Mo2 x 共晶高熵合金摩擦学性能的影响

Effect of Mo Addition on Tribological Properties of Al19Fe20- x- Co20- x Ni41Mo2 x Eutectic High-Entropy Alloys

摘要:

研究了Al₁₉Fe_20-xCo_20-xNi₄₁Mo_2x（x=0，1，2，3，4，5）共晶高熵合金（EHEAs）的摩擦学性能。结果表明，添加微量Mo的EHEA可形成面心立方（fcc）+B2共晶组织，而添加相对较高含量Mo的EHEAs可形成fcc+B2+μ树枝状组织。Mo元素有利于提高L1₂相的强度和B2相的延性。然而，随着Mo含量的增加，生成的富Mo μ相降低了EHEAs的强度和塑性。Al₁₉Fe₁₈Co₁₈Ni₄₁Mo₄ EHEA具有高强度和高延展性的最佳组合。增加Mo含量可以提高EHEAs的抗氧化性。随着Mo含量的增加，EHEA在滑动过程中形成了抗氧化性增强的摩擦氧化物层，摩擦系数单调下降。本研究为Al₁₉Fe_20-xCo_20-xNi₄₁Mo_2x EHEAs的摩擦学性能研究提供了指导。

Abstract:

Tribological properties of Al₁₉Fe_20-xCo_20-xNi₄₁Mo_2x (x=0, 1, 2, 3, 4, 5) eutectic high-entropy alloys (EHEAs) were investigated in this research. Results show that EHEAs with trace Mo addition can form the face-centered cubic (fcc)+B2 eutectic microstructure, whereas EHEAs with relatively higher Mo content can form fcc+B2+μ dendritic microstructure. Mo element is beneficial to the strength enhancement of L1₂ phase and the ductility improvement of B2 phase. However, with increasing the Mo content to x>2, the resultant Mo-rich μ phase degrades the strength and plasticity of EHEAs. Al₁₉Fe₁₈Co₁₈Ni₄₁Mo₄ EHEA has the optimal combination of high strength and high ductility. Increasing Mo content can improve the oxidation resistance of EHEAs. With increasing the Mo content, EHEA forms a tribo-oxide layer with improved oxidation resistance during sliding process, and the friction coefficient is monotonically decreased. This research provides guidance for the investigation of tribological properties of Al₁₉Fe_20-xCo_20-xNi₄₁Mo_2x EHEAs.