重熔组织的影响
(北京有色金属研究总院， 北京 100088)
摘 要: 研究了半固态AlSi7Mg合金在不同加热温度制度、 不同保温温度、 不同保温时间下的显微组织。经电磁搅拌的AlSi7Mg合金在固相线—液相线温度区间保温加热时， 共晶相首先熔化， 团块状α相逐渐演变成球状。 随着保温温度的提高，晶粒形状更圆滑； 随保温时间增加， 晶粒形状也更圆滑。 保温温度太高或保温时间太长时， 试样表面有液相析出， 靠近表面部位产生大量孔洞， 试样在自重作用下变形。随炉加热方式所获得的固相颗粒尺寸比热炉加热方式所获得的固相颗粒尺寸大。
关键字: 半固态; 铝合金; 半固态重熔; 组织
（Beijing General Research Institute for Non-ferrous Metals,
Beijing 100088, China）
Abstract:The Microstructure of AlSi7Mg semi-solid alloy remelted at different temperature and different holding time is studied. The results show that heated at the temperature between liquidus and solidus, the eutectic in AlSi7Mg alloy stirred by an electromagnetic field is first remelted, and α-phase gradually evolves into spheroidal-like shape. The higher the holding temperature or the longer the holding time is, the smoother the side of α-phase turns. But if the holding temperature is too high or the holding time is too long, some liquid metal is exuded from the surface of samples, and the samples are deformed by their own gravity. The dimension of the solid phase heated from room temperature is bigger than that heated from a higher initial temperature.
Key words: semi-solid; aluminum alloy; semi-solid remelting; microstructure
