对Al-Cu合金中α-Al及Al_2Cu生长行为的探讨

Research on the α-Al and Al_2Cu's Growth Action in Al-Cu Alloys

研究了Al-Cu合金中-αAl和Al2Cu的生长行为,分析了初生-αAl及初生Al2Cu作为共晶核心形核的能力。结果发现,在过共晶组织中,初生相Al2Cu形貌大部分有明显的拐角,观察其平面有的呈矩形,呈现小面生长特性。而-αAl与Al2Cu共晶生长时,Al2Cu择优生长特征削弱,与-αAl耦合生长呈现非小面-非小面生长,表明Al2Cu在不同的生长阶段表现出的生长行为不同。在亚共晶组织中,初生相-αAl周围形成离异共晶的Al2Cu,而过共晶组织中初生相Al2Cu周围没有离异共晶的-αAl,表明初生相Al2Cu作为共晶层片核心的能力比初生相-αAl作为共晶层片核心的能力强。

The α-Al and the Al2Cu＇s growth action and the ability of the eutectic nucleus formation of the primary crystal phase α-Al and Al2Cu in Al-Cu alloys were investigated by means of Scanning Electron Microscope and X-Ray Diffraction. The results show that most of the primary crystal phase Al2Cu in the hypereutectic structures have obvious corners. Sometimes present rectangle. But when it grows with α-Al in the eutectic structures, it presents different behavior. This proposes that the AlzCu expresses the different growth behavior in the different growth moments. In the hypoeutectic structures, there is divorced eutectic AlzCu around the primary crystal phase α-Al. But in the hypereutectic structures, there is not divorced eutectic α-Al around the primary crystal phase Al2Cu. This proposes that the ability of the eutectic synusia＇ nucleus formation of the primary crystal phase Al2Cu is stronger than the primary crystal phase α-Al＇ s.