(哈爾濱理工大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150040)
摘 要: 為解決工業(yè)態(tài)非細(xì)晶AZ31鎂合金板材氣脹成形能力差、成形極限低等問題，將脈沖電流引入到材料的氣脹成形過程中，并對(duì)工業(yè)態(tài)非細(xì)晶AZ31鎂合金板材進(jìn)行脈沖電流輔助氣脹成形研究。自由脹形實(shí)驗(yàn)表明：脈沖電流可提高工業(yè)態(tài)非細(xì)晶AZ31鎂合金板材的氣脹成形極限。顯微組織分析表明：在脈沖電流輔助變形條件下，非細(xì)晶AZ31鎂合金板材的氣脹成形是多種變形機(jī)制綜合作用的結(jié)果，這包括晶界滑移及擴(kuò)散蠕變，晶內(nèi)位錯(cuò)滑移及孿晶變形等。對(duì)脈沖電流作用機(jī)制的分析表明：脈沖電流可提升位錯(cuò)的擴(kuò)散活性，增強(qiáng)其可動(dòng)性，從而促進(jìn)了上述變形機(jī)制的作用效果，提高了材料的氣脹成形能力。
關(guān)鍵字: AZ31鎂合金；脈沖電流；氣脹成形；位錯(cuò)滑移；孿晶變形
（School of Materials Science and Engineering, Harbin University of Science and technology, Harbin 150040, China）
Abstract:In order to improve the poor formability and forming limit of the commercial non-fine grain AZ31 magnesium, pulse current was employed during the gas blow forming, and pulse current auxiliary gas blow forming of the commercial non-fine grain AZ31 Mg alloy was studied. The results of the free bulging indicate that the forming limit of the commercial non-fine grain AZ31 magnesium can be improved by the pulse current. The microstructures of the formed parts indicate that the forming mechanism of the commercial non-fine grain AZ31 magnesium under pulse current auxiliary is the combined action of many kinds of deformation mechanisms, such as the grain boundary sliding and diffusion creep, dislocation sliding inside the grain and the twin deformation. The mechanism of the pulse current effect on the deformation was studied. The result shows that the dislocation activity can be enhanced by the pulse current, therefore, the formability of the commercial AZ31 magnesium during gas blow forming can be increased.
Key words: AZ31 Mg alloy; pulse current; gas blow forming; dislocation sliding; twin deformation
