Effect of Mo Content on Friction and Wear Properties of Fe-Mn-Al-C Alloys Under Different Working Conditions

Abstract

For this study, Fe-25Mn-9Al-8Cr-1C-xMo alloys (x = 0, 0.1, 0.2, 0.3, 0.4 wt%) were prepared by mechanical alloying combined with vacuum hot-pressing sintering. The corresponding microstructure, mechanical properties, and friction and wear properties under different working conditions (dry friction, oil lubrication and sulfur-containing boundary lubrication) of materials were studied. The results show that the Fe-25Mn-9Al-8Cr-1C alloy is mainly composed of the austenite phase, Cr₇C₃ phase, and a small amount of a-Al₂O₃ phase. After adding Mo element, the Fe₂MoC phase appears. With the increase of Mo content, the tensile strength and elongation of the alloys increase first and then decrease. In particular, when the Mo content is 0.3 wt%, an excellent combination of strength and toughness is obtained. The product of strength and elongation of the Fe-25Mn-9Al-8Cr-1C-0.3Mo alloy reaches a maximum value of 3.69 GPa·%, which is improved by 158.04% compared with the matrix alloys. With the increase of Mo content, the average friction coefficient and volume wear rate of the alloys show a trend of first decreasing and then increasing under different working conditions. Also, the average friction coefficient and volume wear rate of the alloy with 0.3 wt% Mo reach a minimum value, especially under the condition of sulfur-containing boundary lubrication. The average friction coefficient and volume wear rate of Fe-25Mn-9Al-8Cr-1C-0.3Mo alloy are 0.051 and 0.222 × 10⁻⁴ mm³·N⁻¹·m⁻¹, respectively, which are 40.69% and 46.38% lower than those of the matrix alloys.

Keywords:

• Fe-25Mn-9Al-8Cr-1C-xMo alloys
• microstructure
• mechanical property
• sulfur-containing boundary lubrication
• friction and wear mechanism

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research is supported by The Fifth Batch of “Outstanding Young Talents Support Program” in Shaanxi Universities, Shaanxi Youth Innovation Team Project (21JP051), Natural Science Basic Research Program of Shaanxi Province (2021JQ-646), and National Natural Science Foundation of China (grant no. 51705391). Data Center of Management Science, National Natural Science Foundation of China - Peking University; Education Department of Shaanxi Province.