The effect of processing parameters and heat-treatment on the microstructure and mechanical properties of PM CoCrFeMnNiTi0.1 high-entropy alloy

CoCrFeMnNiTi0.1 high-entropy alloy (HEA) was fabricated using mechanical alloying (MA) and sintering. To synthesize the HEA, the equiatomic composition of Cr, Co, Fe, Mn, and, Ni powders and Ti powder (1.0. at%) were ball milled at different times and then pressed and sintered specimens were provided. To investigate the effect of heat-treatment on the structure, sintered samples were heat-treated. The powder morphology, microstructure, X-ray diffraction, phase identification, hardness, and compressive strength investigation were performed. The results showed; over time smaller grain size was approached which led to improving the mechanical properties of the HEA. HEA structure contains FCC phase and the disappearance of XRD peaks, intensity decrement, and peak broadening occurred during milling. Heat-treatment led to round edges for the Cr-rich phase due to the decrease in the distance between the lamellar structure. Grain boundary strengthening and precipitation hardening are considered to be the main reinforcement mechanisms due to the addition of Ti. The 20-h heat-treated sample was nominated as the optimum mechanical properties.

Automated summary

CoCrFeMnNiTi0.1 high-entropy alloy was fabricated using mechanical alloying and sintering, showing that smaller grain size over time led to improved mechanical properties. The addition of Ti resulted in grain boundary strengthening and precipitation hardening, with the 20-h heat-treated sample exhibiting the optimum mechanical properties.