Ayad saad abd Al-karim, Zaid G. A. Al-jlaihawi
Glass-ceramics of the lithium aluminosilicate (LAS) system are widely employed in dentistry; yet optimizing their clinical performance requires specific control of heat treatment parameters. This study aims to investigate the impact of varied processing parameters on the resulting microstructure, mechanical properties, and surface roughness of these materials. The methodology involves systematic control of nucleation temperature (520°C) and crystallizations temperatures (750°C) and (900°C). Materials were micro-structurally characterized and investigated using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM); mechanically using Knoop hardness tests and ultrasound wave velocity (to obtain an elastic modulus; and physically using a surface roughness tester. XRD confirmed the presence of LiAlSi2O6 as the main phase and Li2Si2O5 as a minor phase. Furthermore, the optimal heat treatment of glass-ceramics significantly increased the knoop hardness amounted to ~ 7.66±0.44GPa and the elastic modulus to ~ 96.35±0.50GPa. Surface roughness analysis also revealed a minimum (Ra) of 0.34±0.04μm for the specific heat treatment