Etched base-metal alloys: comparison of relief patterns, bond strengths and fracture modes

The relief patterns, the bond strength and the fracture modes of 8 base-metal alloys were evaluated. Resin-etched metal bonds were established between a pair of etched metal surfaces. The bonds were tested under tension. The relief patterns and the fracture modes were evaluated by SEM. The relief patterns were related to the composition, microstructure and the preferential dissolution of the various phases. The relief patterns appeared retentive for 7 of the eight alloys evaluated. The differences in the bond were statistically significant. Four modes of fracture were identified. The fracture was mainly located in the resin among the alloys with high bond strength. Interfacial debonding occurred in areas lacking three-dimensional relief.