Mechanical properties of interface layers between cosintered alumina and spinel compacts

摘要

The main aim of this study is to investigate the mechanical and structural properties of the interface layer (interlayer) between alumina and spinel materials after high temperature thermal treatment (1600 degrees C). A microstructurally distinct layer with columnar grains of up to 50 mu m length was detected by SEM. Mechanical properties, such as indentation hardness and elastic modulus of the interface layer, parent alumina and spinel parts, were measured and compared by nanoindentation method. According to the results, several microstructural factors including initial alumina raw powders, the intrinsic microstructural inhomogeneity of the interlayers, such as presence of porosities, unresolved hard alumina phase in the microstructures, size of columnar grains and position of grain boundaries were proposed to affect the mechanical properties. Different micromechanical results between the regions of the samples were also attributed to generation of residual compressive stress during grinding and polishing of the surfaces.