Effect of Sintering Temperature and Time on Microstructure and Mechanical Properties of CoCrFeNiMn High-Entropy Alloys

A single-phase equal-atom five-membered High-entropy alloy CoCrFeNiMn was prepared by powder metallurgy. The samples were prepared by discharge plasma sintering technique, and were held at temperatures of 850°C, 950°C, and 1050°C for 5 min, and at temperatures of 1050°C for 3 min, 5 min, and 10 min, respectively. The organization and mechanical properties of the prepared samples were analyzed. The tensile strength and ductility of the alloys gradually increased with the increase of sintering temperature and reached the highest values of 620.0 MPa and 51.0% when the temperature was 1050 °C, respectively. With the increase of holding time, the tensile strength of the alloy gradually decreased and the ductility gradually increased, reaching the highest value of 55.6% when the holding time was 10 minutes. Critical shear stress (τ0) and normal fracture stress (σ0) were introduced to analyze the effects of sintering temperature and holding time on tensile strength and fracture mode. The alloy sintered at 1050°C and held for 3 min had the highest hardness value of 191 HV, the best wear resistance, and the wear mecha-nisms were mainly adhesive and abrasive wear.