Effects of reduction of diameter on microstructure and surface roughness of rotary swaged magnesium by FEA
(College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China)
Abstract: 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.
Key words: magnesium; rotary swaging; FEA; processing optimization; microstructure