2021 Volume 62 Issue 8 Pages 1231-1238
A high-entropy alloy (HEA) is a multi-component alloy obtained by blending at least five metal elements at compositions of 5–35%. Contrary to expectations, HEAs have a simple microstructure and exhibit unique properties such as excellent high-temperature strength, high tensile strength, and extremely slow diffusion rate. They are mainly produced by casting method, and heterogeneous microstructures have been found in the as-cast structure. Powder metallurgy has many advantages over ingot-metallurgical methods such as casting, including excellent material efficiency and ease of conversion to complex shapes. In this study, we produced a CrFeCoNiSi HEA and evaluated its properties. The Si content was changed within the range of 5–15 at% to investigate the characteristics of the corresponding HEAs. A Vickers hardness test and a corrosion test were performed. The Vickers hardness test revealed that the hardness of the samples of (CrFeCoNi)95Si5 and (CrFeCoNi)90Si10 was approximately 550 HV, whereas that of (CrFeCoNi)85Si15 was approximately 700 HV. (CrFeCoNi)95Si5 and (CrFeCoNi)90Si10 showed significant improvement in corrosion resistance. In constant, deterioration was observed for the (CrFeCoNi)85Si15 sample due to the presence of excess Si, which formed a stable silicide with metal elements.
