(1. 沈陽航空航天大學(xué) 材料科學(xué)與工程學(xué)院，沈陽 110036；
2. 中國科學(xué)院 金屬研究所，沈陽 110016)
摘 要: 對AZ31鎂合金軋制板材進(jìn)行變形方向依次為軋向(RD)、橫向(TD)、軋向和橫向的變路徑壓縮實(shí)驗(yàn)，研究變形過程中的力學(xué)性能，并采用電子背散射衍射(EBSD)觀察上述變形過程中晶粒取向變化，分析孿晶變體的啟動情況。結(jié)果表明：在變路徑壓縮過程中，各路徑壓縮過程依次對應(yīng)拉伸孿晶、二次孿晶、解孿晶和拉伸孿晶的微觀變形機(jī)制，首次變形所產(chǎn)生的預(yù)應(yīng)變提高后續(xù)變形中孿晶形核啟動力，使后續(xù)變形過程的屈服強(qiáng)度大幅增加。二次孿晶的啟動遵循Schmid定律，孿晶變體啟動的選擇性傾向明顯，由t1或t5變體來完成二次孿晶。
關(guān)鍵字: AZ31鎂合金；變路徑壓縮；屈服強(qiáng)度；二次孿晶；孿晶變體
（1. College of Materials Science and Engineering, Shenyang Aerospace University, Shenyang 110036, China;
2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China）
Abstract:The multi-path compression with sequential RD→TD→RD→TD deformation direction was performed on the AZ31 magnesium alloy rolled sheet, and the mechanical property of the previous deformation was studied, the electron backscatter diffractometry (EBSD) was applied to observe the grain orientation evolution during the above deformation, and the activations of twin variants were analyzed. The results show that the deformation mechanism of extension twin, - secondary twin, detwin and extension twin are sequentially related to each compression during the above deformation. The activity stress for twinning nucleation during the subsequent deformation is raised by the pre-straining generated from the first compression, which increases the yielding strength significantly during the subsequent deformation. The activation of - secondary twin follows the Schmid criterion, and there is an obvious selective tendency for twin variant activation, twin variant t1 or t5 are activated to start the - secondary twin.
Key words: AZ31 magnesium alloy; multi-path compression; yielding strength; secondary twin; twin variant
