Influence of high temperature holding on tensile strength of pan-based carbon fiber reinforced aluminum-magnesium alloy composites fabricated by ultrasonic infiltration method

Carbon fiber reinforced aluminum alloy composites (CF/AL composites) are expected to be applied to electric power cable due to superior specific strength and specific modulus. But it is reported that CF/AL composites form aluminum carbide (Al ₄C ₃) at the interface between carbon fiber and aluminum alloy. However, influence of operating temperature, in usual 300°C, on the growth of Al ₄C ₃ and tensile strength of CF/AL composites have not been clarified. In this study, at first, PAN-based CF (M40J)/AL composites are fabricated with ultrasonic infiltration method and hold at 300, 450, 500°C for 64 h. Secondary, influence of holding temperature on the quantity of Al ₄C ₃ was investigated. Thirdly, relationship between the quantity of Al ₄C ₃ and tensile strength of CF/AL composites was examined. As holding temperature increased, the quantity of Al ₄C ₃ increased and tensile strength decreased. By examining extracted fiber with SEM, it was found that tensile strength should be decreased because Al ₄C ₃ corroded carbon fiber. Kinetics calculation indicated that remaining strength of the CF/AL composites, held at 300°C for 36 years, was nought. As a result, it will be difficult to apply the CF/A1 composites to electric power cable.