한국주조공학회

Aluminum base composites reinforced with various amount of SiC particles and Mg contents have been investigated by different fabrication method for twenty-years. In this paper, how the decomposition and dissolution behaviors of SiCp(20μм) in the melt of Al composites arised was studied. As the results, the decomposition and dissolution of SiCp into the melt of Al composites increased with increase of the temperature above720℃, and holding time at a given melting temperature. Because SiC is thermodynamically unstable in this Al-SiCp composite at temperature above the liquidus, SiCp dissolves and reacts with Al in matrix to form Al_4C_3 according to following chemical equation 4Al+3SiC- >Al_4C_3+3Si, Si decomposed and dissolved from SiCp increases Si content of matrix, while liquidus temperature of matrix decrease with increase of SiC content in matrix. The hardness of SiCp decreased with increase of the melting temperature, the hardness of the matrix /particle interface increased with increase of the melting temperature due to increase of the Mg_2Si and Al_4C_3 intermetallic compounds, etc.