凝固条件对AlSi_7Mg合金半固态加热时组织的影响  

Effect of the Solidification Conditions on the Microstructures of AlSi_7Mg Alloy during Semi-solid Remelting

作　　者：毛卫民[1] 钟雪友[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《北京科技大学学报》1998年第3期253-257,共5页Journal of University of Science and Technology Beijing

基　　金：国家"863"基金资助项目

摘　　要：利用电阻炉研究了凝固条件对AlSi_7Mg 合金半固态加热时组织的影响.研究表明:电磁搅拌的AlSi_7Mg 合金在589或597℃下保温,在较短的时间内(5～10 min),共晶体即可重熔,α相可转变为球状,而且保温温度越高,试样共晶体重熔和α相球化的过程越快;相比较,未电磁搅拌的细小枝晶的AlSi_7Mg 合金在同样的加热温度下,即使保温60min,也无法获得完全球状α相的半固态组织.The effect of the solidification conditions on the microstructures was stud- ied during partial remelting of AlSi_7 Mg alloy with the help of an electrical pipe-type furnace. The results show that the eutectic is remelted above all and α phases are gradu- ally evolved into spheroidal shape, if the AlSi_7Mg alloys stirred strongly by rotating electro- magnetic field during the first solidification are heated again to 589℃ or 597℃ and have been held for a short time(for example, 5～10 min), and moreover, the higher the holding temperature, the faster the eutectic remelting process and α phase's evolution are. In contrast, even though the AlSi_7 Mg alloy's samples non-stirred with fine dendritic microstructures ate heated to the same temperatures as those stirred by rotating electromagnetic field and have been held for 60 min, it is not possible to change all the dendritic α phases to sper- oidal α phase.

关 键 词：铝合金 重熔 铸造 凝固 加热 组织 

分 类 号：TG292[金属学及工艺—铸造] TG244.3