Ductility Improvement of an AZ61 Magnesium Alloy through Two-Pass Submerged Friction Stir Processing

作者：Luo, Xicai; Cao, Genghua; Zhang, Wen; Qiu, Cheng; Zhang, Datong^*

来源：Materials, 2017, 10(3): 253.

DOI：10.3390/ma10030253

• AZ61 magnesium alloys
• friction stir processing
• microstructure
• texture
• mechanical property

Friction stir processing (FSP) has been considered as a novel technique to refine the grain size and homogenize the microstructure of metallic materials. In this study, two-pass FSP was conducted under water to enhance the cooling rate during processing, and an AZ61 magnesium alloy with fine-grained and homogeneous microstructure was prepared through this method. Compared to the as-cast material, one-pass FSP resulted in grain refinement and the beta-Mg17Al12 phase was broken into small particles. Using a smaller stirring tool and an overlapping ratio of 100%, a finer and more uniform microstructure with an average grain size of 4.6 mu m was obtained through two-pass FSP. The two-pass FSP resulted in a significant improvement in elongation of 37.2% +/- 4.3%, but a slight decrease in strength compared with one-pass FSP alloy. Besides the microstructure refinement, the texture evolution in the stir zone is also considered responsible for the ductility improvement.

• 出版日期2017-3
• 单位华南理工大学