Mechanical Performance Improvement by Nitrogen Addition in N-CoCrNi Compositionally Complex Alloys

Abstract

In this study, the effects of nitrogen addition on the phase formation and mechanical properties in compositionally complex alloy (CCA) of N-CoCrNi are investigated. Recrystallized N-CoCrNi exhibits Cr2N precipitate formation on the microstructure. The Cr2N formation is found to inhibit grain growth during recrystallization, causing fine grain sizes in N-CoCrNi. The microhardness and yield strength are also significantly improved in N-CoCrNi compared to CoCrNi. This occurs owing to several strengthening mechanisms by nitrogen addition to N-CoCrNi via solid-solution, grain boundary, and Cr2N precipitation hardening. It is observed that nitrogen addition is a cost-effective method to provide a potential strengthening element in CCAs, particularly in a CoCrNi matrix.