Plastic flow behavior, microstructure, and corrosion behavior of AZ61 Mg alloy during hot compression deformation

AZ61 alloy was hot-compressed on a Gleeble-2000 thermal simulation testing machine, and the compression flow stress, microstructure, microhardness, and corrosion properties of samples with three different geometries were analyzed after deformation at temperatures ranging from 573 K to 773 K and a strain rate of 0.5 s−1. The true stress-true strain curves of the as-extruded AZ61 Mg alloy indicated that the deformation behavior significantly depended on the testing temperature. The flow curves exhibited typical flow behavior with dynamic recrystallization softening. The geometry affected the formability of AZ61 alloys; increasing the aspect ratio (H/D) reduced the strain-hardening coefficient (nh) and increased the strain-softening coefficient (ns). But in the CU sample with a raised collar shape, the strain-softening phenomenon was retarded. Increasing the deformation temperature increased the grain size and decreased the microhardness. The corrosion behavior of AZ61 compressed alloys deteriorated with increased temperature, especially at 773 K.