Si-Ca,Si-Ba及Ca-Ba二元合金熔体组元活度的计算

Calculation of Component Activities in Si-Ca, Si-Ba and Ca-Ba Binary Alloy Melts

根据Miedema二元合金生成热模型,结合相关热力学数据,对硅钙钡系中的每个二元合金在1623K下的活度进行计算·结果表明,采用该模型对Si Ca合金活度的计算结果与实测结果吻合较好,Si Ca合金与Si Ba合金计算结果相对于理想熔体有较大负偏差,说明Ca及Ba原子与Si原子都有很强的相互作用,Ba Ca合金熔体在整个成分范围内较为接近理想熔体,Ca原子与Ba原子相互作用不大·

Based on Miedema for calculating the formation heat of binary alloy system, the activity of each and every binary system in the Si-Ca-Ba alloy system was calculated at 1?623?K combining with related thermodynamic data. The calculation results showed that although the activity of Si-Ca alloy confirms fairly with measured data, the activity curves of Si-Ca and Si-Ba alloy melts show relatively great negative deviation from the idea melt. It means that there is a strong interaction between Ca and Si atoms and between Ba and Si atoms. In comparison, the Ba-Ca melt comes nearer to the idea melt in the whole range of composition, and the interaction between Ca and Ba atoms is weaker.