An effective rolling process of magnesium alloys for suppressing edge cracks: Width-limited rolling  

作　　者：Jing Tian Huihu Lu Wanggang Zhang Huihui Nie Quanxin Shi Jiafei Deng Wei Liang Lifei Wang 

机构地区：[1]College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China [2]Shanxi Key Laboratory of Advanced Magnesium-based Materials,Taiyuan University of Technology,Taiyuan 030024,China [3]Instrumental Analysis Center of Taiyuan University of Technology,China

出　　处：《Journal of Magnesium and Alloys》2022年第8期2193-2207,共15页镁合金学报（英文）

基　　金：supported by National Natural Science Foundation of China under Grant Nos. U1810208, 51474152U1710254 and 52005362;Shanxi province science and technology major projects under Grant No. 20181101008。

摘　　要：To suppress the edge crack of the magnesium alloy sheet during the ordinary rolling process, a new rolling process named width-limited rolling was proposed in this paper. Width-limited rolling is a rolling method in which the width of the alloy sheet is limited by modifying the shape of the rollers, allowing a compressive stress field to form at the edge portion of the alloy sheet during rolling, resulting in the reduction of edge cracks. At present work, magnesium alloy sheets were separately subjected to ordinary rolling and width-limited rolling. The microstructure evolution and mechanical properties of the rolled sheets were investigated by EBSD, TEM, and XRD. The results exhibited that under the same rolling conditions, the sheet after ordinary rolling exhibited obvious edge cracks while no crack was found at the edge of the sheet after width-limited rolling. The edge crack suppressing effect was attributed to the reduction of the tensile stress along rolling direction during WLR, promoting the synchronous extension of the edge and center regions to suppress edge crack tendency. Microstructure observation showed that the compressive twins formed in the sheet after ordinary rolling usually exhibited as thin plates and cannot continue to fully develop due to the premature generation of the edge cracks. However, the compressive twins developed maturely in some of which double twins formed and various slip systems with different dislocation Burgers vectors occurred in the rolled sheet after WLR. More twin intersections and shear bands, providing more potential recrystallization nucleation sites, which are beneficial to weaken basal texture. With the cooperation of twinning and dislocation slip, the texture of the sheet after the width-limited rolling is weakened and the mechanical properties are improved.

关 键 词：Width-limited rolling Texture Twinning deformation Dislocation DRX 

分 类 号：TG339[金属学及工艺—金属压力加工]