MICROHARDNESS, SURFACE TOUGHNESS AND AVERAGE COORDINATION-NUMBER IN CHALCOGENIDE GLASSES

Glasses covering the entire glass formation region in the GeSbSe chalcogenide system were prepared using 5- to 6-nines pure raw materials and careful processing techniques. Vickers microhardness and surface toughness of these, as well as several other isostructural glasses prepared similarly, were made using the microindentation technique. The microhardness of most of the glasses increased linearly with the average coordination number 〈r〉. The surface toughness showed a maximum at 〈r〉 {reversed tilde equals} 2.6. The empirical relationships between glass composition and the two properties so derived are examined, to some extent, in light of percolation concepts in these covalently bonded solids. © 1990.