Adhesive Behaviour of the Alloys “ALBABOND E” Containing Large Percentage of Pd after Various Surface Treatments

Abstract

The alloy “ALBABOND E”, consisting mainly of palladium was given various kinds of surface treatment and then adhered with two different adhesive resins. The surface treatments were: mirror-polishing, sand-blasting with alumina, electrolytical etching, Sn plating and for the last step heating once to 400°C. The adhesive used were: 4-META-MMA-TBB type resin and PANAVIA EX. For comparison, an alloy containing only a small percentage of Pd was tested. To examine the adhesive bonding strength it was tested by thermal cycle for a maximum of 2000 times. The samples were dipped for 1-1 minutes in water of 4°C and 60°C alternatively and then the tensile bonding strength was measured. The treatments that were successful were oxidation by heating, Sn plating and Silicoating in this order and out of two adhesives the durability of adhesive bonding strength of 4-META type resin was stronger than that of PANAVIA EX. The electrolytical etching made the surface rough but had no effect to the adhesive bonding strength, which appears to be because the precious metallic components of the alloy are retained in larger quantities on superficial layer.