earticle

영어

The effect of Nb on interfacial bonding characteristics of Ni-Cr alloy for porcelain fused to metal
crown (PFM) has been studied in order to investigate oxide layer. A specimens , which is 0.8 in
thickness, were fired at 1,000 with four tests such as air, vacuum, air for 5 minutes and vacuum
for 5 minutes in order to examine an oxide behavior of alloy surface generated by the adding of Nb to be controlled at a rate of 0, 1, 3 and 5. It observed oxide film form of the fired specimens with optical microscope and scanning electron microscope (SEM), and chemical formation of them with energy disperse X-ray spectroscopy (EDX). The other specimens, which is 2 in thickness, were fired at 1,000 with air and vacuum in order to analyze the diffusion behaviors of alloy-porcelain interface by X-ray dot mapping.
The results of this study were as follows:
1. The observation of microstructure of specimens by SEM showed that the more Nb content is
high, the more much intermediate compound of rich Nb is observed. 2. The surface morphology of oxide film is most dense in 3% Nb. The heat treatment in air
constitutes denser oxide film than heat treatment under vacuum.
3. The diffusion behavior of oxide layer by X-ray dot mapping showed that Si, Al of porcelain
diffuse toward metal.