[Fundamental studies of precious alloys for porcelain fusing. (2) Deformation of Au-Pt-Pd ternary alloys on porcelain firing (author's transl)].

In order to compare the deformation of the castings in the firing process with the results of the previous paper, 1/10-tapered ring type thimble crowns were prepared using nine Au-Pt-Pd ternary alloys of the same composition as in the previous paper. The deformation in the firing process was determined by the shoulder gap change measurement. Conclusions are summarized as follows. 1) The correlation between the thermal expansion hysteresis H and the shoulder gap change K is highly significant (r= 0.96, phie=7),and it can be represented by the following equation: K(mm)=0.15 + 1.22 H(%) 2) The gap change increases with increase of Pt content. 3) Most of the deformation occurs in degassing treatment, while in the other firing process the deformation scarcely occurs.