Hot Deformation Behavior of Ni3Al-based Alloy MX246A Original Research Article

The hot deformation behavior of homogenized Ni3Al-bascd alloy MX246A has been characterized on the basis of its flow stress variation obtained by isothermal constant true strain rate compression testing on the MTS 810 machine in the temperature range of 1150–1225 °C and strain rate range of 0.001–0.1 s−1. Microstructural observation revealed striped secondary γ′ phase which was vertical to compression axis, and precipitation of fine ternary γ′ phase. The amount of striped secondary γ′ phase reduced and that of fine ternary γ′ phase increased with increasing temperature and decreasing strain rate. The material exhibited peak stress followed by flow softening, but no obvious steady-state flow behavior. Microstructural investigations have shown no dynamic recrystallization happened. TEM studies indicated that the flow softening was controlled by dynamic recovery mechanism.