(東南大學(xué) 機(jī)械工程系， 南京 21001)
摘 要: 采用X射線能譜儀和X-ray Mapping對反應(yīng)產(chǎn)物進(jìn)行分析， 由Al-Si合金中不同Sr， B含量時(shí)枝晶/α/和共晶Si形態(tài)與大小的變化， 考察了Sr與B的交互作用。 研究發(fā)現(xiàn)： Al-1B中間合金在經(jīng)Sr變質(zhì)處理的近共晶Al-Si合金中具有強(qiáng)的枝晶細(xì)化能力， 而Sr的存在對B的枝晶細(xì)化效果起一定的促進(jìn)作用； 但當(dāng)合金中Sr和B含量較高時(shí)存在互毒化現(xiàn)象， 這是由于Sr與B摩爾比接近3∶4的未知化合物形成時(shí)消耗了熔體中大量的Sr和B。 Sr-B化合物的發(fā)現(xiàn)為Sr， B間互毒化機(jī)理提供了直接依據(jù)
關(guān)鍵字: 鋁硅合金； 鍶； 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
