Diffusional Strengthening of Glass
Gover H.*, Leyland A. and Hand R.J.
Department of Materials Science and Engineering, University of Sheffield,
Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
This project involves the implantation and diffusion of nitrogen into silicate glass surfaces to produce higher strength glass components.
Fundamentally diffusion processes can be used to strengthen glass. It is well known from earlier investigations that substituting 3-fold coordinated nitrogen atoms for 2-fold coordinated oxygen atoms positively affects the mechanical properties of silicate glasses. Hence, nitrogen incorporation into silicate glasses is practical both chemically and physically . However, nitridation of glass surfaces is limited in extent and time consuming to carry out using conventional techniques, such as annealing under nitrogen or ammonia atmospheres . In the current work we are using plasma nitridation to provide higher diffusion rates and hence reduced treatment times, nanoindentation will be used to measure the elastic modulus and hardness values of treated and untreated samples; these results and their relationship to the treatment conditions will be compared and discussed.
1) Hans Otto Mulfinger, Physical and Chemical Solubility of Nitrogen in Glass Melts. Journal of the American Ceramic Society 9(9), (1966) pp .462-467.
2) Dériano, S. et al., Mechanical strength improvement of a soda-lime-silica glass by thermal treatment under flowing gas. Journal of the European Ceramic Society, 24(9), (2004) pp.2803?2812.