(1. 沈陽工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，沈陽 110870；
2. 遼寧裝備制造職業(yè)技術(shù)學(xué)院 實習(xí)實訓(xùn)中心，沈陽 110161)
摘 要: 采用分離式Hopkinson壓桿和反射式拉桿裝置在室溫對擠壓態(tài)AM30鎂合金進(jìn)行動態(tài)壓縮和拉伸試驗，分析AM30鎂合金在沿擠壓方向(ED)和橫向(TD)壓縮和拉伸時的變形機(jī)制，計算AM30鎂合金在ED和TD方向壓縮和拉伸時的應(yīng)變速率敏感系數(shù)，并通過SEM觀察斷口形貌。結(jié)果表明：沿ED方向壓縮時，拉伸孿晶{ }á ñ是主要變形機(jī)制，屈服強(qiáng)度對應(yīng)變速率不敏感；沿ED方向拉伸以及TD方向壓縮和拉伸時，拉伸孿晶不能啟動，位錯滑移參與變形，應(yīng)變速率敏感系數(shù)提高；AM30鎂合金在ED方向表現(xiàn)出很強(qiáng)的拉壓不對稱性，壓縮/拉伸屈強(qiáng)比約為0.38，在TD方向則無明顯的拉壓不對稱性；AM30鎂合金在動態(tài)壓縮和拉伸時斷口形貌呈韌脆混合的斷裂特征。
關(guān)鍵字: 鎂合金；孿生；應(yīng)變速率敏感性；變形機(jī)制；織構(gòu)
extruded AM30 magnesium alloy
（1. School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China;
2. Center of Practising and Training, Liaoning Equipment Manufacture Vocational College of Technology,
Shenyang 110161, China）
Abstract:The dynamic compressive and tensile tests on the extruded AM30 magnesium alloy were carried out at room temperature using a split Hopkinson pressure bar and a reflected Hopkinson tension bar apparatus. The deformation mechanisms of the AM30 magnesium alloy under the dynamic compression and tension loading along the extruding direction (ED) and the transverse direction (TD) were analyzed. The strain rate sensitivity coefficients of the alloy under different conditions were calculated and the dynamic fractograph of the alloy was analyzed. The results show that, when the alloy is compressed along the ED, tension twining { }á ñ is the main deformation mechanism, and the yield stress of the alloy is insensitive to the strain rate. When the alloy is tested under tension along the ED and under tension and compression along TD, tension twining { }á ñ is not initiated, while the dislocation slip is responsible for the plastic deformation, resulting in the fact that the strain rate sensitivity becomes higher. The asymmetry of the tension-compression of AM30 magnesium alloy is much pronounced along the ED and the yield stress ratio of compression to tension is about 0.38. The fractograph of the alloy is mix-fractured morphology under dynamic compressive and tensile conditions.
Key words: magnesium alloy; twining; strain rate sensitivity; deformation mechanism; texture
