(东南大学 机械工程系， 南京 21001)
摘 要: 采用X射线能谱仪和X-ray Mapping对反应产物进行分析， 由Al-Si合金中不同Sr， B含量时枝晶/α/和共晶Si形态与大小的变化， 考察了Sr与B的交互作用。 研究发现： Al-1B中间合金在经Sr变质处理的近共晶Al-Si合金中具有强的枝晶细化能力， 而Sr的存在对B的枝晶细化效果起一定的促进作用； 但当合金中Sr和B含量较高时存在互毒化现象， 这是由于Sr与B摩尔比接近3∶4的未知化合物形成时消耗了熔体中大量的Sr和B。 Sr-B化合物的发现为Sr， B间互毒化机理提供了直接依据
关键字: 铝硅合金； 锶； 硼； 互毒化； 交互作用
in Al-Si casting alloys
（Department of Mechanical Engineering， Southeast University，
Nanjing 210018， China）
Abstract:The interaction between Sr and B in Al-Si casting alloys was investigated by observing the changes of the morphology and size of the dendritic α and eutectic silicon phases using energy-dispersive X-ray tracing and X-ray mapping. It is found that Al-1B master alloy has a strong power of dendrite refinement in near-eutectic Al-Si casting alloys modified with strontium and strontium enhances the dendrite refinement of boron. But， there is a mutual poisoning phenomenon between Sr and B when the Sr and B contents in alloys are excessive. It could be interpreted by the discovery of an compound in which the mole ratio of Sr to B is close to 3∶4. The formation of this compound consumes a great deal of Sr and B in melts. The observation of the Sr-B compounds affords a direct evidence for the mechanism of the mutual poisoning between Sr and B.
Key words: Al-Si alloy； strontium； boron； mutual poisoning； interaction
