凸模错距量对镁合金弯曲构件动态再结晶的影响  

Effect of Staggered Distance on Dynamic Recrystallization of Magnesium Alloy Bending Products

作　　者：李峰[1] 王雁鹏 张熙杰 LI Feng;WANG Yan-peng;ZHANG Xi-jie(School of Electric and Engineering,Harbin University of Science and Technology,Harbin 150040,China)

机构地区：[1]哈尔滨理工大学材料科学与工程学院

出　　处：《哈尔滨理工大学学报》2019年第5期29-33,共5页Journal of Harbin University of Science and Technology

基　　金：国家自然科学基金(51975166)

摘　　要：传统弯曲构件成形工艺存在工序流程长、曲率调控难度大等瓶颈问题。错距挤压工艺能够在单道次挤压成形过程中实现挤压-成形一体化,同时,通过改变凸模端部的错距量h,达到控制弯曲构件曲率特征的目的。由错距挤压工艺获得的AZ31弯曲构件经过EBSD测试,分析了凸模错距量h对弯曲构件的晶粒形貌、平均晶粒尺寸、晶界分布、晶粒取向和施密特因子的影响。研究结果表明,随着凸模错距量h的增加,AZ31镁合金构件发生了充分的动态再结晶,晶粒得到细化,且由于凸模结构的特殊性,弯曲构件中平行于挤压方向的晶粒数量增加,晶粒取向由原先的软取向转为硬取向。为镁合金弯曲构件错距挤压成形微观组织演变的研究提供了科学指导。Traditional bending processes have many bottlenecks,such as long processing flow and difficulty in controlling bending characteristics.The staggered extrusion(SE)process can realize the integration of extrusion and bending in a single pass.The bending characteristics of bending products can be controlled by adjusting the staggered distance(h)of the stem.The AZ31 bending products obtained by the staggered extrusion process was observed by EBSD.The influence of the staggered distance on grain morphology,average grain size,grain boundary distribution,grain orientation and Schmid factor of bending products was investigated,respectively.The results show that the dynamic recrystallization of AZ31 magnesium alloys occurs and the grains are refined with the increase of the h.Because of the special structure of the stem,the number of grains parallel to the extrusion direction in the bending products increases,and the grains change from the original soft orientation to the hard orientation.The above phenomena provide scientific guidance for the investigation of microstructure evolution in staggered extrusion of magnesium alloy bending products.

关 键 词：AZ31镁合金 错距挤压 凸模错距量 晶粒形貌 动态再结晶 施密特因子 

分 类 号：TG376[金属学及工艺—金属压力加工]