锑对共晶硅形貌变质作用的研究

Modification of Antimony on Microstructures of Si-Eutectic

利用SEM对加锑变质的铝硅共晶合金的金相及深蚀试样进行观察。研究共晶硅的平面及立体形貌,结果表明:锑可以使共晶硅的形貌由板片状转变成纤维杆条状,变质作用与钠相似;只是锑的变质能力较弱,须借助快冷实现;板片状与纤维杆条状实属同一种晶体生长方式,硅晶体生长速度较慢时,杆条侧向生长相联形成板片状,而晶体生长速度快时,杆条侧向生长来不及,仍为杆条状。

Microstructures of Si-eutectic in Al-Si eutectic alloys modified with Sb were investigated by means of SEM.The result shows that microstructure of Si-eutectic may be changed from flake to fibrous staff by Sb, and Sb is similar to Na in modification;but in modifying ability Sb is weaker, more than Na, thus when Sb is used it need's to cooperate with quickly cooling;flake and fibrous staff both are results of same growthing fashion of Si crystal, if growth speed of Si crystal is slower, staffs join each other by flank growth to form flakes, if the speed is extremely fast, staffs do not change because flanks are too late grown.