钡对共晶铝硅合金组织和性能的影响

用含钡合金对共晶铝硅合金（ＺＬ１０９）进行变质处理，观察了钡的加入量、变质作用时间以及重熔次数等对合金组织和性能的影响。结果表明：钡在一定剂量范围内对共晶硅有良好的变质作用，同时具有良好的抗变质衰退能力和重熔特性，变质合金可获得较高的强度。借助扫措电镜和波谱仪对钡变质共晶硅的空间形貌和钡元素的分布状况进行了观察，并以此讨论钡的变质作用机制。

The Effect of Barium on the Microstructure and Properties of Al-Si Eutectic Alloys

Modification of Al-Si eutectic alloy(ZL109 ) with a barium-rich alloy was investigated.Experiemental variables such as the amount of Ba contained,the holding time after putting--in and the remelting times were researched on the microstructure and properties of the testing alloys.The results shown that there exsists a good modificative effect of barium on the eutectic silicon when retained barium amount is 0. 025 % -0. 125A%wt,and also exsist a good remeltability and much longer holding time. The testing alloys have yet gained a higher mechanical properties after modificated with Ba. Discussion was made upon the crystal type of silicon modificated with Ba and the mapping of Ba in the alloy by means of SEM and EPMA.