Effect of Process Parameters on Plastic Formability and Microstructures of Magnesium Alloy in Single Point Incremental Forming

Abstract

In this paper, using a combination of simulated and experimental results and macroscopic and microscopic observations, we explain the effect of three process parameters: the forming temperature, forming tool radius, and the forming feed rate on the plastic formability of single point incremental forming of AZ31 magnesium alloy sheet in single point incremental forming from macroscopic and microscopic perspectives. The results show that the forming temperature and the tool-head radius strongly affect the macroscale experiment and the microstructure of AZ31 magnesium alloy sheet, whereas the effect of the feed rate is small. At a forming temperature of 250 °C, tool-head radius of 5 mm, and a feed rate of 0.7 mm, the magnesium alloy sheet exhibits a relatively good forming state, the thickness variation of the formed part is uniform, which is favorable for achieving uniform sheet forming, reducing stress concentration, and reducing the possibility of cracking. Under these conditions, the grain size of the magnesium alloy is relatively uniform; compared with the grain size in the microstructure of 6061 aluminum alloy, the grain size of the magnesium alloy is smaller.