The Influence of Multi-Phase Intermetallic Compounds on the Microstructure and Tribological Behaviors of 6061 Al Alloy by Adding AlCoCrFeNi High-Entropy Alloy

The AlCoCrFeNi high-entropy alloy (HEA) obtained by vacuum arc melting furnace was introduced into 6061 Al alloy, and a new aluminum matrix composites was prepared by traditional casting method. This paper mainly studies the changes in the microstructure and friction properties of the 6061 Al alloy after introducing 5.0 wt% HEA. With the help of testing apparatus such as optical microscope (OM), scanning electron microscope (SEM), electron probe microanalysis (EPMA), Vickers Hardness Tester and friction testing machine to analyze the microstructure and friction properties of AMCs. Results indicated that the addition of HEA lead to the precipitation of intermetallic compounds (AlCoFeNi, AlCrFe) and nano-scale AlCoFeNi phases with rod morphology distributing in the matrix alloy, and the average diameter of nanophases is approximately 200 nm. Compared with the 6061 Al alloy, the hardness and friction properties of the AMCs were significantly improved. The hardness of AMCs is extremely increased to 70 HV (6061Al alloy: 45.5HV). The coefficient of friction (COF) decreased by 61.8% from 1.78 to 0.68 and wear rate decreased by 43.4% from 2.56 x 10(-13) m(3)N(-1)m(-1) to 1.45 x 10(-13) m(3)N(-1)m(-1), when the introduction of HEA reached 5.0 wt%.