Effects of reduction of diameter on microstructure and surface roughness of rotary swaged magnesium by FEA

Combining the processing maps with FEA, the critical values of reduction of diameter (ΔR) for the appearance of as-cast microstructure, dynamic recrystallization grains and twins in the swaged magnesium were respectively studied, by which the rational range of ΔR was obtained. To ensure that the as-cast microstructure wouldn't be retained in the rotary-swaged magnesium, ΔR should be larger than 0.25 mm. To avoid the appearance of twins in the microstructure of rotary-swaged magnesium, ΔR should be less than 1.0 mm. ΔR should be between 0.25 mm and 1.0 mm to ensure the appearance of recrystallized grains. The surface roughness of rotary-swaged magnesium increases with the increase of ΔR by quadratic function. The simulated results accord well with the experimental data. In the process control of rotary-swaging(RS), ΔR should be maximized between 0.25 mm and 1.0 mm on the precondition that the requests for surface roughness have been satisfied.