Étude comparative par indentation des caractéristiques mécaniques de verres sodo-calcique et vitrocéramique rodés et polis par des grains abrasifs liés

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. Mots clés : Verre / polissage / indentation / ténacitéAbstract -Comparative study by indentation test of the mechanical characteristics of sodalime and ceramic glasses ground and polished by bound abrasive grains. In this work, indentation toughness of 4 optical glasses (Crown K5, Heavy flint, Float glass and Zerodur r ) was analyzed regarding its surface quality. Despite the large number of the involved technological parameters, polishing of brittle materials by abrasive bonded grains shows a high efficiency and a better surface quality compared to polishing by free abrasive grains. This method has allowed obtaining roughness parameters, Ra and Rq, about 30-40 nm. Instrumented indentation tests were performed by varying the load from 5 to 300 N. A good reproducibility was achieved. Pop-in in glass ceramic was observed from 50 N, whereas it only appears from 100 N on heavy flint and float glasses and they are not highlighted on crown glass. Indentation toughness was calculated by means of the cracks length using different relationships based on hypotheses concerning the cracks geometry. Anstis, Tanaka, Niihara and Laugier equations were employed. Finally, the results obtained from these equations and their dispersions are compared.