Thermal Expansion Behavior of Al/Magnesia Metal Matrix Composites

The coefficient of thermal expansion (CTE) of aluminum matrix composites having different volume fractions of MgO particulate have been investigated. The composites were produced powder metallurgy technique by mixing and packing MgO nanoparticles of 100 nm. The experimental results for composites indicate negligible hysteresis in the CTE curves during heating and cooling cycles. Comparison is made between the experimental data and several model predictions. Among the model predictions, the Kerner, Turner and Scahpery models offer the highest values. Turners equation gave the best correlation between mechanical and thermal-expansion characteristics of the composites. All the other equations can be used as well, because the coefficient of correlation is over 90 %.