The effect of microstructure evolution on mechanical properties in novel alumina-montmorillonite composites

Fabrication of alumina matrix composites reinforced with montmorillonite (MMT) is introduced in this work. Specimens were prepared with the use of powder metallurgy and consolidated using the Spark Plasma Sintering (SPS) method. Investigations were then carried out on the influence of MMT addition on microstructure, mechanical properties and tribological performance of the alumina matrix composites. Scanning Electron Microscopy (SEM) revealed significant changes in microstructure where elongated, abnormally overgrown grains of alumina can be observed in areas contacted with montmorillonite. This unusual bimodal microstructure greatly influenced the measured mechanical properties and friction study. Tribological examinations exhibited outstanding results, where samples with montmorillonite addition demonstrate significant improvement in the wear in comparison to pure unmodified alumina sinters.