Alumina-silicate glass interfacial properties probed by micromechanical testing techniques

Micromechanical properties of the interfaces between alumina and calcium-alumino-silicate (CAS) glasses were tested using various micro/nanoindentation techniques. The interfaces were produced by depositing continuous films of anorhtite (CaAl2Si2O8) onto single-crystal α-Al2O3 of two crystallographic orientations by pulsed-laser deposition (PLD). The mechanical behavior of the interfaces was examined using two different depth-sensing indentation instruments. Three types of tests, namely indentation, microscratch, and in-situ indentation combined with atomic force microscopy (AFM) imaging were conducted using different operating modes. The deformation behavior observed for the indentations and microscratches has been correlated with irregularities observed in the load-displacement curves. In the first two cases, scanning electron microscopy (SEM) has been used to characterize the deformation structures associated with the deformed regions. The in-situ experiments allow force-displacement measurements and AFM imaging immediately before and after indentation. The preindent and postindent morphology of the surface could-then be characterized.