An introduction of the fluorine and Nitrogen on properties of Ca-Si-Al-O glasses

Ca-sialon glasses have been known for some time [1] and they are effectively calciumalumino-silicate glasses containing nitrogen which improves their mechanical properties. calcium alumino-silicate glasses containing fluorine are known to have useful characteristics as potential bioactive materials [2]. therefore,the combination of both nitrogen and fluorine additions to these glasses may give useful glasses with enhanced mechanical stability. this paper gives a review of oxynitride glasses and reports glass formation and evaluation of glass properties in the ca-si-al-o-n-f system. within the previously defined glass forming region in the ca-si-al-o-n system,homogeneous,dense glasses are formed. however fluorine decreases the glass transition temperature,the density and the mechanical properties of the glasses while nitrogen increases them. therefore,it appears that fluorine acts as a network modifier while,on the contrary,nitrogen acts as a network former even in presence of fluorine.