铸造Al-Si合金中Sr与B的交互作用

Interaction between Sr and B in Al-Si casting alloys

采用X射线能谱仪和X rayMapping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。

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.