EXAMINATION OF MICROHARDNESS INDENTATION-INDUCED SUBSURFACE DAMAGE INALUMINA 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 micro scopy (CSLM). The suitability of the CSLM technique as a quick and non destructive method of obtaining three-dimensional information of subsu rface damage in dispersion reinforced brittle matrix composite materia ls was demonstrated. The addition of alumina platelets to the glass ma trix has resulted in a reduction in the extent and depth of subsurface damage due to indentation, and hence may make the material more resis tant to erosive wear, This damage development may be a consequence of the presence of residual compressive stresses in the matrix and the st rong platelet/matrix interfacial bending.