Creep of Magnesium Composites Investigated by the Acoustic Emission Technique

Operating conditions for most MMCs involve thermal and/or mechanical loading, which may induce internal stresses, structural changes, and matrix creep characterized by dislocation generation and motion. Under higher load and/or long-term exposure, structural damage (interface decohesion, fiber fracture) may also occur. Since acoustic emission (AE) is a response to the above mechanisms, it is possible by AE measurements to identify and characterize the microstructure changes and to correlate them with the creep behavior. Materials include AZ91/Saffil, QE22/SiC, and AZ91/SiC.