冷却过程中共晶组织的形成和转变  

The Formation and Change of Eutectic Structure during the Cooling Process

作　　者：蔡惠民[1] 梁济[1] 

机构地区：[1]天津大学

出　　处：《热加工工艺》1994年第5期21-23,共3页Hot Working Technology

摘　　要：采用液淬方法，探讨了共晶成分铝硅合金在冷却过程中共晶组织的形成和转变规律。研究表明：在共晶温度以上（包括共晶温度）的激冷试件中，呈现亚共晶组织，存在着初生α和共晶硅的粗化过程；共晶α首先依附在初生α四周形成，然后两相共同伸向共晶液体；同时，在初生α内部也有硅相析出；从凝固结束到室温的缓慢冷却过程中，高于固溶度的硅继续析出，硅片继续粗化，使初生α与共晶α的差别消失，最后形成科大硅片均匀分布在固溶体基体上的共晶组织。The laws of the formation and change of eutectic structure of Al-Si alloy during cooling process have been investigated using liquid quenching method. The hypoeutectic structure of the test sample water-quenched at and above eutectic temperature is showed. During cooling process there are thickening processes of primary dendritic α and Si phases. First, the eutectic α phase forms attached upon the primary α phase, then two phases of eutectic structure extend into remaining liquid, meanwhile, Si phase precipitates from dendritic α phase. From the temterature of the end of solidification to room temporature, precipitating and thichening of Si phase continue and the difference between primary α and eutectic α disappears. Finally, the structure that thick Si flakes disperse evenly in αmatrix forms.

关 键 词：铝硅共晶合金 共晶组织 液淬 粗化 

分 类 号：TG166.3[金属学及工艺—热处理]