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通过透射电子显微镜观察,织构分析和激活能计算,对锌—铝共晶合金超塑性进行了研究。该细晶合金在较宽的温度和速率范围内变形时具有超塑性。应变速率敏感性指数 m 大于0.3。在最佳变形温度和速率条件下,可获得大于900%的延伸率。实验结果分析表明:该合金的超塑性变形机理可用界面滑动,晶内位错运动和原子沿界面扩散的叠加来解释,并以此解释了几个实验现象。对均匀变形和 m 值的物理意义进行了讨论。
The superplasticity of zinc-aluminum eutectic alloy was studied by transmission electron microscopy, texture analysis and activation energy calculation. The fine crystalline alloys are superplastic when deformed over a wide range of temperatures and rates. Strain rate sensitivity index m is greater than 0.3. Under the optimal deformation temperature and rate conditions, more than 900% elongation can be obtained. The experimental results show that the superplastic deformation mechanism of this alloy can be explained by the superposition of interfacial sliding, intragranular dislocation movement and atom diffusion along the interface, and several experimental phenomena are explained. The physical meanings of uniform deformation and m value are discussed.