Oxygen diffusion in ceramic suspensions for stereolithography

Optical profilometry and real-time infrared (RTIR) spectroscopy have been performed to determine the influence of oxygen diffusion in ceramics suspensions on stereolithography accuracy. As expected, oxygen tends to lower both polymerized depth and width by inhibiting the polymerization and scavenging the radicals. Researches concern the influence of process parameters (atmosphere composition and temperature) and dispersion formulation, through viscosity, its filler content or tertiary amine addition, on oxygen diffusion. Models, such as those of Wilke-Chang and Mackie and Meares, were used to fit the oxygen diffusivity in the piezoelectric ceramics suspensions. This study has led to the modification of the stereolithography process in order to allow piezocomposites fabrication with a higher accuracy. (C) 2002 Elsevier Science B.V. All rights reserved.