The formation of B2-precipitate and its effect on grain growth behavior in aluminum-containing CoCrNi medium-entropy alloy

Abstract

B2-precipitate formation in Al7.45(CoCrNi)92.55 (at.%) was investigated after two-stage annealing. Prior face-centered cubic (FCC) grain growth has been successfully controlled using the pinning effect of B2-precipitate. Electron backscattered diffraction analysis was utilized to study the preferential growth direction of B2-precipitate during the second-annealing process. B2-precipitate as the partially coherent particle, exhibited Kurjumov-Sachs orientation relationship (OR) with FCC matrix in {111}FCC//{110}B2 plane and 〈110〉FCC//〈111〉B2 direction. This orientation relationship altered the interface of B2-precipitate and FCC grain. The matched OR between B2-precipitate and FCC grain was effectively hindered the grain growth of FCC grain by giving the Zener pinning pressure.