Laser scanning parameters on fabrication of ceramic parts by liquid phase sintering

Layer manufacturing for fabricating ceramic parts has been carried out by a wet process known as Ceramic Laser Sintering; the process employed ceramic slurry comprised of silica powder, clay, silica gel, and water. The aim of the present research is to establish a systematic method for measuring the width and depth of the scan line on the ultra-thin layer sintered with the laser scanning. Besides laser power and scan speed, laser beam diameter was also included as one of the significant scanning parameters. Furthermore, to optimize the scanning process, a 'critical point' was defined. The working temperature at the critical point is near the melting point of the silica powder. By varying the laser power, the scan speed, and the beam diameter, the optimized scanning parameter combinations can be obtained to produce a series of critical line depths at the critical points. Based on the critical line depth, a proper layer thickness for fabricating sintering part can be determined. Parts possessed inter-connective porous structure, better surface quality, and higher strength can be obtained by employing the optimized scanning parameter combinations. (C) 2008 Published by Elsevier Ltd.