Abstract
The influence of heat treatment, working temperature, working rate, lubricant, etc. on the upsettability of AZ61 Magnesium alloy were investigated, in order to makeclear the conditions of warm precise forging. From the warm compression test in axial direction of extruded billet using concentrically grooved tool, the deformation resistance showed work hardening and work softening in following apparent yielding, in not depending on grain size by heat treatment. The peak values of were about 450 and 430 [MPa] at 180 and 200℃ respectively. In every warm upsetting, mushroom deformation in upper portion of upsetted specimen was occurred in the temperature range of 180∿300℃. This mushroom deformation is the peculiar unstable phenomena in extruded AZ61 billet and start in work hardening range.
