原位反应TiC颗粒对液相线铸造法制备半固态铝合金组织的影响  

Effect of In-situ Synthesized TiC Particulates on Microstructure of Liquidus Casting Semi-solid Al Alloys

作　　者：刘慧敏[1] 廖庆华[1] 由国艳[1] 格日乐[1] 

机构地区：[1]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051

出　　处：《铸造技术》2008年第7期905-908,共4页Foundry Technology

基　　金：国家自然科学基金资助项目(50661003)

摘　　要：采用原位反应液相线铸造法制备7075+X%TiC(体积分数X=0、0.8、1.0、2.0)半固态铝合金坯料,选择590℃对其进行二次加热实验,保温时间分别为5、20、30min,并与液相线铸造7075铝合金的相同条件下的组织相比,探索原位TiC颗粒对液相线铸造铝合金组织的影响。结果表明,当原位TiC颗粒达到2%时,合金铸态组织基本变成等轴晶;二次加热后平均晶粒尺寸随着保温时间的延长具有长大现象,但是随着原位TiC颗粒的含量增加,长大幅度变小,颗粒抑制晶粒长大程度增强。The semi-solid aluminum alloy billets, of 7075 AI alloy with 0, 0.8, 1.0, 2.0 vol. % TiC were prepared by in-situ reaction liquidus casting. The billets were then reheated at 590℃, holding for 5, 20 and 30 min. The effect of in-situ synthesized TiC particulates on microstructures of liquidus casting AI alloys were investigated in comparison with liquidus casting 7075 AI alloy at the same conditions. The result shows that almost all as-cast microstructure is equiaxed grains when the fraction of in-situ synthesized particulates is up to 2%. The average grain size of the alloy after secondary heating increases with increasing the holding time. However, the degree of grain growth becomes small and particulates can restrain the grain growth with increase of fraction of TiC particulates.

关 键 词：原位TiC颗粒 液相线铸造 半固态铝舍金 显微组织 

分 类 号：TG249.9[金属学及工艺—铸造]