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

In this study, Cantor alloys were prepared via powder metallurgy using spark plasma sintering (SPS) technology. The sintering parameters were systematically controlled, as follows: three temperature gradients (850 °C, 950 °C, and 1050 °C with a fixed holding time of 5 min) and three holding time gradients at 1050 °C (3, 5, and 10 min). The effects of the sintering parameters on the microstructure and mechanical properties were thoroughly analyzed. As the sintering temperature increased, the elemental particle bonding became more uniform, the internal porosity decreased, and densification improved, leading to gradual enhancements in the tensile strength and ductility. Conversely, a prolonged holding time reduced the grain boundary energy and induced grain growth, resulting in improved ductility but decreased strength. The critical shear stress (τ0) and normal fracture stress (σ0) were introduced to analyze the influence of the sintering temperature and holding time on the tensile strength and fracture modes. Wear morphology observations revealed scratches and stepped features in all of the samples, indicating that the dominant wear mechanism was adhesive wear.