Effect of pretreatments on the metal–ceramic bonding strength of a Pd–Ag alloy

AbstractObjectives rpose of this study was to evaluate the efficacy of surface treatments on the bonding properties between a metal and ceramic. s metal specimens were divided equally into four groups of 15 samples each. These groups received different treatments (Gr1: 250 μm Al2O3 + preoxidation; Gr2: 250 μm Al2O3 + degassing; Gr3: 120 μm Al2O3 + preoxidation; Gr4: 120 μm Al2O3 + degassing). Bond strengths were evaluated using a three-point bending test. The results were analyzed using 2-way ANOVA and Tukeyʹs test. Scanning electron microscopy and energy dispersive spectroscopy were used to observe the microscopic features, elemental compositions and distributions, and diffusion in the specimens. Mechanical profiler was used to measure the roughness of metal surface. s nd strengths of the four groups ranged from 45.00 ± 3.63 MPa to 51.61 ± 5.91 MPa, with significant differences (P < .05). The specimen that received the pretreatment of 250 μm Al2O3 air-particle abrasion + degassing had the highest bond strength. Heating under different oxygen partial pressures caused the final Pd–Ag alloys to have varying degrees of internal oxidation and different quantities of metallic nodules. None of the elements in either the ceramic or the Pd–Ag alloy layer diffused into the other layer. sions tal–ceramic specimen subjected to air-particle abrasion with 250 μm Al2O3 and degassed before porcelain firing had significantly higher bond strength than specimens treated differently.