Corrosion Behavior Of Ni-Cr PFM Alloy Fabricated By Laser Rapid Forming Technology

Because of the good mechanical properties, low price and excellent bond strength of metal-ceramic,Ni-Cr PFM alloy has become one of the most important metal materials in prosthodontics. But the comparatively low corrosion resistance constrains its development in more wide areas. So, the improvement of its corrosion resistance shows important clinical significance. In recent years, Laser rapid forming(LRF) technology has being quickly developed. A full density complex metal component can be rapidly fabricated without molds by LRF technology. With this technology, we can process the products with excellent properties within a shorter time. Moreover, it is possible to solve the problem of comparatively low corrosion resistance of Ni-Cr PFM alloy by this technology. Therefore, in this study, we prepared the Ni-Cr PFM alloy by LRF technology and evaluated the corrosion resistance in many aspects in order to lay the foundation for its further utilization in clinical fields.In our study, we prepared the Ni-Cr PFM alloy by LRF technology and evaluated the consistency of the ingredients of the alloy before and after formation. After the corrosion resistance of the alloy was investigated by the static immersion test, stress corrosion test and electrochemical test, we analyzed the sensitivity of the alloy to different corrosion in three different aspects.Resluts :1. The profile of the LRF Ni-Cr PFM alloy was regular, the properties were good. There wasn't any processing defects under scanning electron microscope. Energy spectrum analysis showed that the ingredients were steady for the powder and the formation. The ingredients were similar with Heraenium S Ni-Cr PFM alloy. In the whole process, no impurity element was brought into the formation and no ingredient was lost.2. Static immersion test showed that in both neutral and acidic artificial saliva, the elements release of the LRF Ni-Cr PFM alloy were significantly less than the control groups.3. Stress corrosion test showed that the corrosion resistance of the LRF Ni-Cr PFM alloy was significantly better than the control group .4. Electrochemical test showed that no matter in neutral or acidic artificial saliva, the free corrosion potential of the LRF Ni-Cr PFM alloy was significantly higher, the free current density was significantly lower, the film resistance and transfer resistance were significantly higher. All of them showed better corrosion resistance of the LRF Ni-Cr PFM alloy.In our study, we evaluated the corrosion resistance of the LRF Ni-Cr PFM alloy in three aspects. The results showed that the Ni-Cr PFM alloy fabricated by LRF was better than the common Casting Alloy. This study showed the better application in stomatology of LRF technology in the future.