(湖南大學 材料科學與工程學院，長沙 410082)
摘 要: 探討采用小異速比多道次異步軋制技術提高AZ31鎂合金板材室溫成形性能的可行性，研究異步軋制板材微觀組織的特點、形成機理及其與成形性能間的內在聯(lián)系。結果表明：多道次異步軋制所累積的剪切應變能有效促進壓縮孿晶的交互作用，細化合金晶粒組織，削弱(0002)基面的織構強度；異步軋制AZ31鎂合金板材后續(xù)退火處理后的室溫伸長率和Erichsen值分別可達32%和6.14 mm；(0002)基面織構減弱和塑性應變比的降低是板材室溫成形性能提高的根本原因。
關鍵字: AZ31鎂合金；異步軋制；織構；孿晶；成形性能
magnesium alloy produced by differential speed rolling
（School of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:To explore the possibility for enhancing the room temperature formability of AZ31 magnesium alloy sheets by multiple pass differential speed rolling(DSR) technic with small-speed ratio, the characteristic of microstructures and formation mechanisms for DSRed sheets were studied, and the intrinsic relationship between the microstructure and formability was discussed. The results show that the accumulated shear strain induced by multiple pass differential speed rolling promotes the interaction of compression twins. Furthermore, fine-grained microstructure and weakened (0002) basal texture can be achieved. A higher ductility with elongation of 32% and an evidently enhanced press formability with Erichsen value of 6.14 mm at room temperature are presented for as-DSRed/annealed specimen. The weakened (0002) basal texture intensity and lower plastic strain ratio are thought to be mainly responsible for the enhancement of room temperature formability.
Key words: AZ31 magnesium alloy; differential speed rolling; texture; twins; formability
