Synthesis of the AlCrCuMnNi high entropy alloy through mechanical alloying and spark plasma sintering and investigation of its wear behavior

Abstract

In this research, AlCrCuMnNi high entropy alloy (HEA) was produced through mechanical alloying (MA) process and then was subjected to spark plasma sintering (SPS) process at different temperatures. The structural and microstructural properties of the alloy were examined after each process. The sample SPSed at 900 °C was then subjected to wear test at room temperature (RT) and 400 °C. The results of MA process were consistent with the thermodynamic analysis results as they revealed the formation a dual-phase HEA after 90 h of milling, which consisted of face-centered cubic and body-centered cubic phases. Increasing SPS temperature led to an increase in the hardness and density of the alloy due to the higher quality of sintering and formation of intermetallic compounds. Additionally, it was seen that the wear resistance of the AlCrCuMnNi HEA is higher at 400 °C compared to RT due to the formation of a hard oxide film on the sliding surface and reduction of the friction coefficient. Moreover, the wear mechanisms of the AlCrCuMnNi HEA at RT were delamination and adhesion which changed to abrasive wear and delamination at elevated temperatures.