【摘要】 本文用差热分析法研究了Al-Si共晶合金、亚共晶合金的动态凝固过程。结果表明,Sr和Sb均提高Al-Si合金的共晶析出温度和降低Al-Si共晶的结晶体速度。同时,通过Al-Si共晶合金液与Si晶面之间润湿角的测量和界面张力的计算发现,Sr与Sb原子均无Si晶面上的热力学吸附倾向,但会在Si晶面上富集,故Al-Si合金的变质阈值与合金的冷速有关。更多还原

【Abstract】 The influence of Sr and Sb on the solidification process of Al-Si alloys. was investigated by differential thermal analysis(DTA). The contact angles between the melt and silicon substrates were measured, and the interfacial energies were calculated. It was obtained that Sr and Sb in the melt raised the Al-Si eutectic nucleation temperature and retarded the eutectic crystallization. Sr and Sb in the melt had no thermodynamic tendeney to absorb on silieon crystals, which was contrary to the traditional point of view. But Sr and Sb might accumulate on silicon crystals and affect the growth of Al-Si eutectics because the partition coefficients were less than 1.更多还原