Al_2O_(3sf)/AZ91D-Y镁基复合材料二次重熔及等温压缩研究

Research on Secondary Remelting Microstructures and Isothermal Compression of Al_2O_(3sf)/AZ91D-Y Magnesium-based Composite

为了推动半固态加工在镁基复合材料成形中的应用,采用液态浸渗法制备出体积分数为10%的Al2O3sf/AZ91D-Y镁基复合材料,并采用等径道角挤压对镁基复合材料进行了形变诱导。再对镁基复合材料进行了二次重熔,并采用等温压缩实验对镁基复合材料在半固态下的力学性能进行了研究。研究表明:在550℃和560℃时延长保温时间有利于组织的球化,在560℃比550℃时,更加能促进晶粒的结晶球化;在相同的应变速率下,压缩变形时的峰值应力随着加热温度升高而降低;在相同的加热温度下,应变速率越大,峰值应力越大。

To promote the application of semi-solid processing in the field of forming magnesium-based composites,Al2O3sf/AZ91D-Y composites reinforced with alumina fibers（10%） were manufactured by the liquid infiltration and then were deformed by equal channel angular extrusion（ECAE）.Then secondary remelting microstructures of Al2O3sf/AZ91D-Y composites were done and the experiment of semi-solid state isothermal compression was employed to study Al2O3sf/AZ91D-Y composites＇ mechanical characterization of semi-solid.The results demonstrated that extending insulation work was propitious to spheroidizing grain in 550 ℃ and 560 ℃.It was more propitious to spheroidizing grain in 560 ℃ than that in 550 ℃.Al2O3sf/AZ91D-Y composites that were extruded by equal channel angular extrusion were done by experiment of semi-solid state isothermal compression,which revealed that at the same strain rate,the peak stress reduced along with rise in temperature;at the same temperature,the higher the strain rate,the higher the peak stress.