Papers by Keyword: Yada Model

Abstract: The grain size evolvement of AZ31 magnesium alloy during high ratio extrusion (HRE) was investigated by experiment and numerical simulation. A Yada model was established according to the results of experimental study and trial calculation. Effects of the deformation temperature, extrusion ratio and extrusion velocity on the grain size were analyzed. The results showed that the microstructure of the AZ31 alloy was dramatically refined by high ratio extrusion. The deformation conditions exhibited obvious effects on the grain size, and the deformation conditions were interplaying and interacting with each other during the HRE process. Compared to the deformation temperature and extrusion velocity, the severe plastic deformation induced by the high ratio extrusion is a major cause of grain refinement. With the increasing of the extrusion velocity, the grains could be refined due to a shorter recrystallized grain growth time. At the same time, the deformation temperature increased with the increasing of the plastic strain rate, which results in faster recrystallized grain growth. Finally, recommended method is advised to further refine the grain size.

Abstract: Both experimentation and calculation of the Yada model modulus of casting AZ31 magnesium alloy are provided in this paper. Based on revised Yada model, the microstructure simulation of precision forming inner gear is performed using Superform software. On the basisi of result analysis, the microstructure transformation of the casting magnesium alloy in the hot-forming process is forecasted in terms of revised Yada model.