SLM OF NET-SHAPED HIGH STRENGTH CERAMICS: NEW OPPORTUNITIES FOR PRODUCING DENTAL RESTORATIONS

摘要

Oxide ceramics yield excellent mechanical properties along with outstanding thermal and wear resistance. However, little work on additive Manufacturing (AM) of high-strength ceramics has been stated. In the present paper the current state of development in Selective Laser Melting (SLM) of pure ceramic specimens is reviewed. During the present approach the eutectic mixture of pure alumina (Al_2O_3) and zirconia (ZrO_2) powder is completely molten while crack formation is prevented by a high-temperature CO_2-laser preheating. This approach yields net-shaped, fully dense specimens reaching flexural strengths of above 500 MPa without post-processing. One potential application for this technology are fully-ceramic dental restorations frameworks, as the demanded maximum loads of above 1000 N are met. Alternative preheating strategies are presented to allow for manufacturing larger volumetric parts.