Hot Deformation Behavior of Ni 3 Al-based Alloy MX246A
摘要
The hot deformation behavior of homogenized Ni3Al-based alloy MX246Ahas been characterized on the basis of its flow stress variation obtained by isothermal constant true strain rate compression testing on the MTS 810machine in the temperature range of 1 150-1 225℃and strain rate range of 0.001-0.1s-1.Microstructural observation revealed striped secondaryγ′phase which was vertical to compression axis,and precipitation of fine ternaryγ′phase.The amount of striped secondaryγ′phase reduced and that of fine ternaryγ′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.