An evaluation of the creep characteristics of an AZ91 magnesium alloy composite using acoustic emission

Creep experiments were undertaken to determine the potential for using acoustic emission (AE) to monitor the high temperature deformation of an unreinforced AZ91 magnesium alloy and a similar alloy reinforced with short alumina fibers after a conventional T6 heat treatment. Samples of each material were tested to failure and the fracture surfaces of selected specimens were examined using scanning electron microscopy. The results show there is an improved creep resistance in the composite by comparison with the unreinforced alloy. It is demonstrated that the use of AE provides a sensitive procedure for monitoring the nature of the creep deformation.