Bonding Strength Investigation of Plasma-sprayed HA Coatings on AluminaSubstrate with Porcelain Intermediate Layer

摘要

Hydroxyapatite (HA) has recently been used as a bonesubstitute in orthopedic and dental surgery applications, owingto its excellent biocompatibility. However, the poormechanical properties of HA limit the material's application inthe loading condition. In this study, HA was coated onto thesurface of alumina substrate, with a view to overcome the poormechanical properties of HA and the biocompatibility ofalumina. Improvement of the bonding strength of HA coatingsto alumina substrate was attempted by adding a bond coat ofporcelain via plasma-spraying and by post heat-treatment.HA-50wt% porcelain and pure porcelain were used tomanufacture two kinds of bond coat before HA coating, andthen all the specimens were heat-treated at 750°C, 800°C,850°C, 900°C for 0.5 hours. The results shows that the bondstrength between HA coating and Al2O3 substrate could beimproved by employing the porcelain as the bond coat afterthe heat treatment. The strengthening mechanisms of the twosystems are discussed.