Evaluation of heat damage on B_4C particulate reinforced aluminum alloy matrix composite using acoustic emission techniques

摘要

Aluminum alloys reinforced with B_4C particle of average particle size of 10.5 #mu# m and 20.9 #mu# m were exposed to 535 deg C for various duration. The material degradation was evaluated by both mechanical and acoustic emission monitoring during tensile tes. The micromechanisms of fracture changed from particle fracture and debonding, for as received specimens, to particle/matrix debonding after exposure to high temperature. The cumulative acoustic emission (AE) events during post heat exposure reduced with the increase of heat damage on the specimen. A Weibull probability distribution function that incorporates heat damage and relates to the cumulative events is developed. This model could be used to evaluate the extent of heat damage to a composite specimen