Nanocrystalline Mg–MAX composites: Mechanical behavior characterization via acoustic emission monitoring

This paper reports on the mechanical behavior characterization of a nanocrystalline Mg–matrix composite reinforced with Ti2AlC by using the acoustic emission (AE) method. When Mg is reinforced with Ti2AlC, the damping is greatly enhanced and, because the Mg grains are in the 50–100 nm range, the resulting composite has excellent mechanical properties. Monotonic and cyclic tensile, as well as low-cycle fatigue tests were carried out while simultaneously recording the AE activity. The latter was analyzed post-mortem and was additionally coupled with advanced pattern recognition techniques for classification and clustering of the AE signals. The results provide evidence related to the activation and evolution of a possibly novel deformation mechanism in this nanocomposite, and are further found to agree with previously reported theoretical and experimental findings.