Experimental Reasearch On Mechanical Properties And Porcelain Bond Strength Of New Domestic CoCr Alloy

Objective: To evaluate the mechanical properties and porcelain bond strength of a new domestic CoCr alloy based on selected laser melting(SLM)technology,and to compare its properties with imported and cast CoCr alloy,so as to provide data support for clinical application.Method: SLM technology was used to construct dumbbell specimens(0°,45° and 90°)and ceramic specimens.The cast specimens of the same size were made by traditional casting method.Tensile test was carried out at room temperature and the shape of the microstructure was observed.The porcelain bond strength was measured by a three-point bend test,and the metal-ceramic interface was observed by scanning electron microscope(SEM)and energy dispersive spectrometer(EDS).Result: There were significant differences(P<0.05)between the casting group,the domestic SLM group and the imported SLM group in their mechanical properties which include elongation,tensile strength and elastic modulus.In the SLM group,there was no significant difference(P>0.05)in elastic modulus,tensile strength and elongation between different fabricated angles.The porcelain bond strength of casting group was(30.78±3.23)MPa,which was lower than imported SLM group(39.31±3.32)MPa)and domestic SLM group(53.89±5.60)MPa.The difference between the three groups was statistically significant(P<0.05).Conclusion: The domestic SLM group obtains the similar mechanical properties to the imported SLM group;the domestic SLM group has higher bonding strength than the imported SLM group and the casting group,which can meet the needs of clinical use.