(西北工业大学物理系，西安710072)
摘 要: 以扩散为模型，并考虑界面反应对初生相溶解过程的影响，建立了初生相在过热熔体中的溶解动力学模型。同时以Al-18%Si(质量分数)合金为对象，在1100 ℃过热情况下，对该模型进行了验证，结果表明：该模型基本上能反应该条件下初生硅的溶解特性。
关键字: 过共晶Al-Si合金；初生相；溶解动力学
（Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710072, P.R.China）
Abstract:As well known, coarse primary silicon phase in Al-Si hypereutectic alloy dentsits mechanical properties, thus limits the application of this alloy. In addition, it has been found that primary silicon in Al-Si hypereutectic alloys was of higher chemical stability in the melt, and its dissolution behavior had directly influence on the freezing microstructure and on the mechanical properties of the alloy. From above, investigating on dissolution character for primary silicon is very emergent. Therefore, the dissolution process of primary silicon particles in Al-18%Si (mass fraction) alloy was studied both by melt overheating experiment and by theoretical analysis, and a dissolution model of primary silicon in the melt was established based on the atomic diffusion and taken account of interface reaction; the results show that the theoretic curve agrees with the experiment one at overheating temperature of 1100 ℃.
Key words: hypereutectic Al-Si alloy; primary phases; dissolution kinetics
