Research On Semi-solid Microstructure And Processing Parameters Of Thixomolding Injection AZ91D Magnesium Alloy

Due to environment protection, energy conservation, high efficiency, the technology of semi-solid metal forming (SSM),is considered as the most potential one for metal forming in the 21stcentury. Magnesium alloy have the advantages of light-weight, high strength/weight ratio, high stiffness/weight ratio, high damping property and electro magnetism shielding property and so on, so recently it has acted an important role in automobile and electric industry as a weight reducing material. But the application of magnesium alloys productions most is die-casting. Die-casting has not been satisfiedwith the require of production colligation properties, because the thin wall accessories and the high performance magnesium alloy accessories used in the auto required with the processing techniques higher and higher. While the thixomolding technique can avert from a series of questions in the traditional casting productions. It is important to study the thixomolding processing parameters. In this paper, mobile shells with AZ91D raw and processed materials are manufactured in the thixomolding machine by modulating different processing parameters. whilst the test of their solid content, denseness, mechanical properties at room temperatures, and Vicker's hardness, effects of the processing parameters on the microstructures and mechanical properties have been investigated using modern analysis and test facilities such as opitical microscopy(OM),X-ray diffractometer (XRD),scanning electron microscopy(SEM) with energy dispersion X-ray analysis (EDAX) etc. Experiment results showed semi-solid microstructure is finer dendrites with solid phase particulates, comparing with Die-casting microstructure, the composition of crystal boundary is same. Comparison with Die-casting microstructure, fine microstructure and solid phase particulates are propitious to mechani...