Influence of interfacial chemical reaction for tensile strength of carbon fiber reinforced aluminum-magnesium alloy composites fabricated by ultrasonic infiltration method

Abstract

Carbon fiber reinforced aluminum alloy composites (CF/Al composites) are expected in aerospace and electric power cable industries due to superior specific strength and specific modulus. But, it is known that CF/Al composites form aluminum carbide (Al₄C₃) at the interface between carbon fiber and aluminum alloy when CF/Al composites are fabricated. However, effects of type of carbon fiber (PAN, pitch) on growth mechanism of Al₄C₃ and tensile strength of CF/Al composites have not been clarified. In this study, at first, CF/Al composites are fabricated with ultrasonic infiltration method. Secondary, effects of type of carbon fiber and fabricating time on quantity and size of Al₄C₃ were investigated. Thirdly, effects of quantity and size of Al₄C₃ on tensile strength of CF/Al composites were examined. The length of Al₄C₃ increased with increase in fabricating time for PAN-based composites. It was suggested that the numbers of nucleating sites of Al₄C₃ increased with an increase in fabricating time for pitch-based composites. As the result, as to the PAN-based composites, it should be controlled less than 100 nm of the length of Al₄C₃ to inhibit degradation of tensile strength. As to the pitch-based composites, fabricating time should be shorter.