变形条件对半固态Al-4Cu-Mg合金微观组织的影响

研究了用应变诱发熔化激活法(SIMA)制备的半固态Al-4Cu-Mg合金在不同变形温度、变形程度和应变速率下半固态压缩变形时的微观组织演变。研究结果表明：在半固态条件下，随变形温度的升高，晶粒平均尺寸增大，分形维数减小；变形程度增大，晶粒平均尺寸减小．分形维数先减小后增大；应变速率增大，晶粒平均尺寸先减小后略有增大，且在小的应变速率下，晶粒平均尺寸随应变速率变化的趋势较大，分形维数随着应变速率的增大而增大。

Effect of the Process Parameters on Microstructure of the Semisolid Al-4Cu-Mg Alloy in the Isothermal Compression Process

Microstructural evolution of the semisolid Al-4Cu-Mg alloy fabricated by strain induced melting activation (SIMA) at different deformation temperatures and strain rates during semisolid deforming were investigated. The experimental results show that the grain size increases with the increase of deformation temperature and decreases with the increase of height reduction. Fractal dimension decreases with the increase of deformation temperature and increases with the increase of height reduction after an early drop. Grain size decreases with the increase from 0.001 s-1 to 0.1 s-1 of strain rate, but increases slightly with the increase from 0.1 s-1 to 1 s-1 of strain rate. The lower the strain rate, the greater effect of strain rate on grain size. Fractal dimension increases with the increase of strain rate.