Microstructural Development and Mechanical Properties of Selective Laser Melted Co-Cr-W Dental Alloy

摘要

Dental restorations are a predestined area for additive manufacturing, due to the required fast fabrication, the low quantities, and the freedom in geometrical designs. Past studies revealed that there is a significant difference in the microstruc-ture compared to traditional investment cast restorations, with drastic implications on the material properties. In many instances, these changes are beneficial, i.e. higher mechanical strength and increased ductility, but at a reduced elastic stiffness. The latter is crucial for the type 5 classification and, based on the studies on a selective laser melted Co-Cr-W dental alloy, a post-heat treatment is inevitable to safely exceed the 150 GPa minimum requirement. Heat treatment at 1150 °C caused a recrystalliza-tion and a formation of tungsten rich precipitates, surrounded by a tungsten depleted cobalt-chromium matrix. In the heat-treated state, the alloy exhibited semi-isotropic tensile properties with an average Young's modulus of about 200 GPa, safely meeting the dental type 2 to 5 classifications.