THERMAL-EXPANSION STUDIES OF PRESTRAINED AL2O3 AL METAL-MATRIX COMPOSITE/

The present study was undertaken to investigate the effect of prestrai ning on the coefficient of thermal expansion (CTE) of 10 and 20 volume percent (v/o) Al2O3 particle-reinforced composite over various temper ature ranges using thermal mechanical analysis (TMA). The CTE of the c omposite was shown to be dependent on the volume fraction of the broke n particle, plastic yielding and flow, and other transformation proces ses occurring at elevated temperatures. The experimentally measured va lues of the CTE were found to be in good agreement with Schapery's mod el at various values of plastic prestrain (0-10%) and with a modified Kerner's equation, at high prestraining (epsilon(p) > 4%) for a wider temperature range.