Metal-ceramic interface characteristics of Co-Cr alloy fabricated by selective laser melting / 中国组织工程研究

ABSTRACT

BACKGROUND: Co-Cr ceramic alloys made by selective laser melting technology are widely used in the field of dental restoration, but the influence of selective laser melting technology on the bonding properties of Co-Cr ceramic alloys is still controversial. OBJECTIVE: To explore the metal-ceramic interface characteristics of dental Co-Cr alloy fabricated by selective laser melting. METHODS: Metal-ceramic specimens were prepared by selective laser melting and precision casting, respectively. Metal-ceramic bond strengths, interface characteristics, fracture analysis, microstructures and composition distribution of specimens were obtained with the aid of universal testing machine, metallographic microscope, scanning electron microscope coupled with energy disperse spectrometer. RESULTS AND CONCLUSION: (1) The metal-ceramic bond strengths of precision casting Co-Cr alloy was higher than that of selective laser melting Co-Cr alloy (P < 0.05). (2) Metallographic microscope showed that selective laser melting Co-Cr alloy had fine grains and a more uniform matrix. Precision casting Co-Cr alloy showed typical casting dendritic structure with coarse grains and a large number of island second phase structures. (3) Scanning electron microscopy showed that precision casting Co-Cr alloy had a thicker diffusion layer than the selective laser melting Co-Cr alloy at the metal-ceramic interface. (4) Scanning electron microscopy showed that the metal-ceramic specimens of precision casting Co-Cr alloy tended to cohesive fracture, and the metal-ceramic specimens of selective laser melting Co-Cr alloy tended to adhesive fracture. (5) The results showed that although the bonding strength of selective laser melting Co-Cr alloy was lower than that of precision casting Co-Cr alloy, the bonding strength of selective laser melting Co-Cr alloy could still meet the requirements of standard YY0621.1-2016.