Gold Alloys for Resin Bonding including Small Amount Base Metals

Structural Changes of Alloy Surface by the High-temperature Oxidation

抄録

To achieve durable bonding with adhesive resin, the surface roughness and the kinds of oxides, respectively to increase mechanical retention to enhance the chemical affinity of adhesive monomer with the gold alloy, were regulated by high-temperature oxidation together with the addition of small amounts of base metals. Alloys containing 2mass% of Ni, In, or Cr with Cu were oxidized at 800°C for 20min in air, pickled in thioglycolic acid, and subsequently oxidized at 500°C for 10min in air. The morphology of the internal oxidation zone changed markedly according to the added base metals. Alhough the internal oxide particle composed of only Cu₂O was removed by pickling, NiO, In₂O₃, and chromium oxides could not removed and remained on the alloy surface. The surface roughness was increased by addition of Ni, In, or Cr. Applying the present method can control the roughness and chemical states on a gold alloy surface to increase its adhesive ability with adhesive resins.