Evaluation of strength and heat-resistance for aluminum-borate whisker reinforced AC8A aluminum alloy composite.

Abstract

An AC8A aluminum alloy matrix composite reinforced with 20vol% aluminum-borate whisker was fabricated by squeeze casting and its mechanical properties were evaluated. Tensile strength of the composite was about 430MPa and 250MPa at room temperature and 573K, respectively. The Young's modulus at room temperature was as high as 107 GPa, while the average thermal expansion coefficient between room temperature and 573K was as low as 14.510-6/ K. The decrease in strength during exposure at up to 573K was small. The composite showed good heat-shock resistance for the heat cycle between room temperature and 673K. The properties of the obtained composite were found to be useful for the elevated temperature materials such as car engine components.