A Study On The Property Of The Gold-Paste Layer Fused To Ni-Cr Alloy

[Objective] The purpose of this study was to better the smoothness of the gold-paste layer fused to Ni-Cr alloy with the sieve and to improve the attrition resistance of the layer blending porcelain powder into the gold-paste.[Materials and Methods] Paint Ni-Cr alloy with gold-paste directly and with 100 mu,300mu,500 mu and 800 mu sieve separately, then bake at 820℃ for 5 minutes. Observe the surface of the gold-paste layer with naked eyes and scanning electron microscopy(SEM) and test the surface roughness with profilometer before and after polishing,. Prepare the gold paste including 10% and 20% porcelain powder separately, then bush and fuse them to Ni-Cr alloy. Test the attrition resistance of the gold-paste layer with an attrition jet test apparatus and the surface roughness before and after polishing. The values of surface roughness and attrition resistance were analysed by ANOVA.[Results] Observed with naked eyes and scanning electron microscopy(SEM), the gold-paste layer became smoother and smoother before and after polishing. The surface roughness of the gold-paste layer reduce prominently with 500 mu and 800 mu sieve (P<0.05). After blending 10% porcelain powder into the gold-paste, the attrition resistance had no difference (P>0.05). After blending 20% porcelain powder into the gold-paste, the attrition resistance rose prominently (P<0.05). When blending porcelain powder into the gold-paste, the surface roughness improved distinctly before polishing (P<0.05) while had no difference from the pure gold-paste layer after polishing (P>0.05).[Conclusion] When we paint Ni-Cr alloy with gold-paste, using the sieve is an effective method to better the smoothness of the gold-paste layer, especially with the800 mu sieve. Profilometer and SEM are good methods to test the surface roughness of the gold-paste layer. Blending porcelain powder into the gold-paste is a feasible way to improve the attrition resistance of the layer and the surface roughness after polishing has no difference. The attrition jet test apparatus is a credible way to test the attrition resistance of the layer.