(1. 沈阳工业大学 材料科学与工程学院，沈阳 110870；
2. 辽宁装备制造职业技术学院 实习实训中心，沈阳 110161)
摘 要: 采用分离式Hopkinson压杆和反射式拉杆装置在室温对挤压态AM30镁合金进行动态压缩和拉伸试验，分析AM30镁合金在沿挤压方向(ED)和横向(TD)压缩和拉伸时的变形机制，计算AM30镁合金在ED和TD方向压缩和拉伸时的应变速率敏感系数，并通过SEM观察断口形貌。结果表明：沿ED方向压缩时，拉伸孪晶{ }á ñ是主要变形机制，屈服强度对应变速率不敏感；沿ED方向拉伸以及TD方向压缩和拉伸时，拉伸孪晶不能启动，位错滑移参与变形，应变速率敏感系数提高；AM30镁合金在ED方向表现出很强的拉压不对称性，压缩/拉伸屈强比约为0.38，在TD方向则无明显的拉压不对称性；AM30镁合金在动态压缩和拉伸时断口形貌呈韧脆混合的断裂特征。
关键字: 镁合金；孪生；应变速率敏感性；变形机制；织构
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
