Abstract
To clarify the interface reaction between porcelain and a commercial Ni-Cr dental alloy (containing higher Cr and Si) during porcelain firing, electron probe microanalyzer (EPMA), X-ray diffraction and X-ray fluorescence analysis have been used to characterize the interface which has emerged by means of selective dissolution of the alloy caused by a bromine-methanol solution. At the early stage of firing, tin oxides (SnO2), contained in the porcelain powder, were reduced to Sn metal and the resultant reduction layer was about 10μm in thickness from the interface. Although in the beginning of firing some Cr oxides were formed at the interface, with increasing retention time (within a few minutes) at 960℃, extremely low oxygen partial pressure caused reduction of even such products.
