Effect of high shear rate on solidification microstructure of semisolid AZ91D alloy  

作　　者：朱光磊 徐骏 张志峰 刘国钧 

机构地区：[1]General Research Institute for Non-ferrous Metals

出　　处：《中国有色金属学会会刊：英文版》2010年第S3期868-872,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project (2009DFB50210) supported by the International Cooperation in Technical Research and Development Program of China;Project (2009AA03Z534) supported by the National High-Tech Research and Development Program of China;Project (2006CB605203) supported by the National Basic Research Program of China

摘　　要：To investigate the effects of rotation speed and shearing time on morphology of semisolid AZ91D alloy,experimental work was undertaken using a twin-screw slurry maker.The results show that increasing the rotation speed and reasonable time can give rise to substantial grain refinement during continuous shearing stage,which can be attributed to the increasing of effective nucleation rate caused by the extremely uniform temperature due to high shear rate and high degree of turbulence.Comparing with low rotation speed at the same thermal condition,the analysis indicates that the microstructures obtained at high rotation speed are homogenous spherical and fine grains instead of dendritic or rosette and exhibits uniform distribution in the eutectic matrix.To investigate the effects of rotation speed and shearing time on morphology of semisolid AZ91D alloy,experimental work was undertaken using a twin-screw slurry maker.The results show that increasing the rotation speed and reasonable time can give rise to substantial grain refinement during continuous shearing stage,which can be attributed to the increasing of effective nucleation rate caused by the extremely uniform temperature due to high shear rate and high degree of turbulence.Comparing with low rotation speed at the same thermal condition,the analysis indicates that the microstructures obtained at high rotation speed are homogenous spherical and fine grains instead of dendritic or rosette and exhibits uniform distribution in the eutectic matrix.

关 键 词：SEMISOLID high SHEAR rate SOLIDIFICATION AZ91D ROTATION speed 

分 类 号：TG292[金属学及工艺—铸造]