中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 29 No. 7 July 2019 |
（1. School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
2. School of Mechanical and Mining Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia;
3. Aerospace Division, Defence Science and Technology, 506 Lorimer Street, Fishermans Bend, Victoria 3207, Australia）
Abstract:A solution-treated AZ91 bulk material was deep-surface-rolled at room temperature to investigate the effect of deep surface rolling on the microstructure and mechanical properties of the alloy. Microhardness and microstructure along the depth of the treated surface layer were characterized. The results show that the affected layer was up to 2.0 mm thick and consisted of three sublayers: a severe deformation layer with thickness of about 400 mm from the topmost surface, a medium deformation layer with thickness of around 600 mm and a small deformation layer up to 1000 mm thick. In addition to grain refinement in the deformation layer, strain-induced precipitation of β phase (Mg17Al12) was observed, particularly in the severe and medium deformation layers. It is believed that the cooperative effects of grain refinement, strain hardening and precipitation strengthening led to the significant increase in hardness of the AZ91 alloy after the deep surface rolling.
Key words: surface deformation; magnesium alloy; deep surface rolling; microstructural evolution; hardness
