Direct Laser Sintering of Al^sub 2^O^sub 3^-SiO^sub 2^ Dental Ceramic Components by Layer-Wise Slurry Deposition

• Published in: Journal of the American Ceramic Society 2006-10, Vol.89 (10), p.3076
• Main Authors: Gahler, André, Heinrich, Jurgen G, Günster, Jens
• Format: Article
• Language: English
• Subjects: Alumina; Ceramics; Heat conductivity; Microstructure; Sintering
• ISSN: 0002-7820; 1551-2916

This publication presents a solid freeform fabrication technique for ceramics in the alumina-silica system by layering binder-free, high-loaded ceramic slurries, followed by selective laser sintering. The low melting silica phase and the reaction sintering between silica and alumina favor the rapid prototyping of pure ceramic parts. On the basis of electroacoustic and viscosity measurements, stable slurries from ... powder mixtures and water with a high fluidity have been prepared for the layer deposition with a doctor blade like in tape casting. Layers with a thickness of about 100 ...m were processed. It was found in laser parameter studies that ceramic parts can only be obtained using special alumina contents and laser parameters. But the biphasic approach may allow greater flexibility in the processing regime than is afforded by the use of just one material. The microstructure of these parts depends mainly on the temperature gradient induced by the laser absorption and thermal conduction. The wet shaping facilitates laser-sintered parts with a relatively high density, which could be increased by a thermal post-treatment. (ProQuest Information and Learning: ... denotes formulae omitted.)