Comparison of the mechanical and tribological properties of a sintered low expansion Li2O-Al2O3-SiO2 glass-ceramic and a commercial cooktop plate

摘要

The mechanical and tribological properties of a new sintered lithium aluminium silicate (LAS) glass-ceramic were compared to those of a commercially Ceran? used in cooktops. The sintered material has no nucleating agents and was obtained by viscous sintering with concurrent surface crystallisation of a glass powder compact whereas the Ceran sample was cut from a plate produced by Schott in the traditional way. Tribological experiments were carried out using a tribometer with reciprocating sliding ball-on-flat method in two controlled conditions: namely 52% relative humidity at 23°C and with running water at 23°C. The sintered glass-ceramic has a hardness of Hn=8-3±0-4 GPa and elastic modulus of E_(IT)=79±2 GPa, whereas the commercial Ceran has a hardness of H_(IT)=9-2±0-2 GPa and an elastic modulus of En=85±l GPa. The tribological tests in dry conditions revealed that the sintered glass-ceramic has slightly lower wear rates than Ceran. Under wet conditions both materials had lower friction coefficients than in dry conditions, but their wear rates were higher. Based on the results plus an additional thermomechanical evaluation (reported in another article), we suggest that this new sintered GC could be an alternative, suitable material for cooktops.