SiCP／AZ61镁基复合材料局部重熔的组织演变

The microstructural evolution of SiC_P/AZ61 magnesium matrix composites during partial remelting

研究了SiCP/AZ61镁基复合材料在局部重熔中的组织演变及其影响因素。结果表明,SiCP/AZ61镁基复合材料局部重熔最佳工艺参数为,加热温度595℃~600℃、保温时间30min^60min。与AZ61基体合金相比,复合材料在局部重熔时的初始分离速率明显较慢;SiCP/AZ61镁基复合材料在重熔过程中具有较高的稳定性,即随温度的提高和保温时间的延长,获得的半固态触变组织更细小。当局部重熔加热温度高于610℃时,复合材料坯料组织易发生严重变形并出现流淌现象,使得重熔试验无法进行。

The microstructural evolution and influencing factors of SiCP/AZ61 magnesium matrix composites during partial remelting was investigated. The results indicated that optimally technological parameters of SiCP/AZ61 magnesium matrix composites were the reheating temperature of 595℃-600℃ and isothermal holding time of 30min-60min. Compared with that of the monolithic AZ61 alloy, a separation tendency of the microstructure of SiCP/AZ61 magnesium matrix composites was slower than that of the monolithic alloy during the initial stage of partial remelting; In the meantime, SiCP/AZ61 magnesium matrix composites possessed high stability during the remelting process and the finer of semi-solid thixoforming microstructure can be obtained with the increasing of temperature and the prolongation of holding time. In addition, the samples of SiCP/AZ61 magnesium matrix composites were susceptible to serious deformation and running out as a flow above 610℃, accordingly it＇s not feasible to perform an experiment during partial remelting.