The Effect of Internal Stress on the Thermal Expansion Coefficient of Al/SiC p Composite

Abstract

The effect of internal stress on the coefficient of thermal expansion (CTE) of the high volume fraction Al/SiCp composite was calculated and studied in a temperature range from 298 to 673 K. The results show that the CTE of composite rises slowly to a maximum value at about 530 K and then decreases with temperature because of the microstress induced by thermal mismatch between aluminum matrix and SiC particles. The macrostress in the composite changes the temperature at which the matrix begins to yield. The calculated CTE of the Al/SiCp composite is consistent with the experimental one before the temperature at which the matrix begins to yield. This temperature has been determined through theoretical calculation, which is well in accord with the experimental result.