STUDY OF HERTZIAN INDENTATION ON A TRANSPARENT VITROCERAMIC AND ON ANALUMINA

An alumina, both as received and in an implanted state with zirconium ions, and a transparent vitroceramic were studied by the Hertzian inde ntation method. The acoustic emission was used for the determination o f the critical fissuration load, P-c. In the three studied materials, this latter is proportional to the radius R of the ball, which validat es the Auerbach law. Effects of abrasion and thermal treatment tempera ture of the vitro-ceramic, as well as ionic implantation of alumina, i nfluence the critical load, P-c. The fracture surface energy, gamma, a nd the critical stress intensity factor, K-IC, of the studied material s were obtained by the use of Warren and Mouginot-Maugis analysis.