Creep and long-term strength of high-entropy alloys

High-entropy alloys are a new class of metallic alloys without a principal component. These materials are attractive because of their unique structures and properties, including mechanical ones. Some high-entropy alloys based on refractory metals are considered as advanced high-temperature materials. In this regard, the study and description of the behavior of such materials under conditions of creep, fatigue and long-term strength is of great interest. In the work, to describe the creep and long-term strength of high-entropy alloys a damage conception is used. A system of interconnected kinetic equations for the creep rate and damage parameter is formulated. A compressible medium is considered, and the mass conservation law is taking into account. The damage parameter is specified in the form of the ratio of the current density of the material to the initial one. The analytical solutions of these equations are obtained. The theoretical creep and long-term strength curves are plotted and compared with the experimental results for CrMnFeCoNi and CrFeCoNi alloys. The experimental results are in good agreement with the theoretical ones.