Examination of microhardness indentation-induced subsurface damage in alumina platelet reinforced borosilicate glass using confocal scanning laser microscopy

Borosilicate glass and borosilicate glass matrix composites reinforced with 10, 15 and 30 vol.% alumina platelets have been indented and the subsurface lateral cracking examined by confocal scanning laser microscopy (CSLM). The suitability of the CSLM technique as a quick and nondestructive method of obtaining three-dimensional information of subsurface damage in dispersion reinforced brittle matrix composite materials was demonstrated. The addition of alumina platelets to the glass matrix has resulted in a reduction in the extent and depth of subsurface damage due to indentation, and hence may make the material more resistant to erosive wear. This damage development may be a consequence of the presence of residual compressive stresses in the matrix and the strong platelet/matrix interfacial bonding.