[X-ray diffraction at the metal-ceramic interface. (Part 2) Surface oxides of 88% Au alloys containing Fe, In, Sn for porcelain fusing (author's transl)].

Fifteen alloys were prepared by adding 0-1.00 wt% Fe, In and Sn (total amount 1.00 wt%) to 88 Au -6 Pt-5Pd-1 Ag master alloy. Before and after the degassing process, the surfaces of these alloys were examined by X-Ray diffraction technique. The crystal structure and the amount of the surface oxides which were formed after the degassing process were determined, and their influence on bond strength between alloys and porcelains was discussed. The results obtained were summarized as follows; 1) In all alloys nonprecious elements were oxidized selectively after the degassing process. 2) On the surface of the alloy to which only Fe, In or Sn was added, Fe2O3, In2O3 or SnO2 was formed respectively. 3) In most cases when two or three nonprecious elements were added together, the above mentioned oxides were formed in mixture. However, something different from them was observed in some of the alloys tested. 4) Quantity of each of the oxides formed was not always in proportion to that of the additives. 5) The lattice parameters of the oxides were depended on the concentration of the additives.