Variational Principle of Si Content in Cast Al-Si Alloy during Melting Process

摘要

The influence of temperate and time on variational principle of Si content in A356 recycled scrap during melting process was investigated in this paper. The results indicated that the variations of Si content showed conic laws which decreased firstly then increased with the holding time. The maximum descent, the full change content and the change rate all increased and the burning time shortened with the melting temperature increasing in the low and high temperature stage respectively. By thermodynamic analysis, we learned the change rates of Si content were decided both by the oxidation reaction of [Si] and reduction reaction of SiO2 by Al. The main factors affecting the redox reactions were O2 content, SiO2 content, melting temperature and so on. The reduction reaction of SiO2 played a major role in Si content with oxygen consumed and SiO2 produced lately.