Aluminum matrix composite reinforced with potassium titanate whisker was prepared by squeeze casting technique. The mechanical properties of the composite are much better than those of matrix alloy and the thermal expansion coefficient decrease greatly. Strain hysteresis was observed in both matrix alloy and composites during thermal expansion experiment at 50～ 280 ℃ . Residual plastic strain occurred in matrix alloy after thermal cycle while the dimension of the composites reinforced with 20% whisker had no change owing to the absence of residual plastic strain

exhibiting excellent thermally dimensional stability.