[Research of the surface oxide film on anodizing Ni-Cr porcelain alloy].
OBJECTIVE
To study the shape, thickness and oxide percentage of major metal element of oxide film on Ni-Cr porcelain alloy after anodizing pretreatment.


METHODS
10 samples were made and divided into 2 groups at random. Then after surface pretreatment, the oxide films of two samples of each group were analyzed using electronic scanning microscope. The rest 3 samples were measured by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES).


RESULTS
Lightly selective solution appeared because the different component parts of the alloy have dissimilar electrode, whose dissolve velocity were quite unlike. The sample's metal surface expanded, so the mechanical interlocking of porcelain and metal increased bond strength. The thickness of oxide film was 1.72 times of the control samples. The oxide percentage of major metal elements such as Cr, Ni and Mo were higher, especially Cr. It initially involved the formation of a thin oxide bound to the alloy and second, the ability of the formed oxide to saturate the porcelain, completing the chemical bond of porcelain to metal.


CONCLUSIONS
The method of anodizing Ni-Cr porcelain alloy can easily control the forming of oxide film which was thin and its surface pattern was uniform. It is repeated and a good method of surface pretreatment before firing cycle.
Zhu
Song
S
Dept. of Prosthodontics, College of Stomatology, Jilin University, Changchun 130041, China.
Sun
Hong-Chen
HC
Zhang
Jing-Wei
JW
Li
Zong-Hui
ZH
D000497:Alloys; D002858:Chromium Alloys; D003776:Dental Porcelain; D016876:Metal Ceramic Alloys; D008855:Microscopy, Electron, Scanning; D009532:Nickel; D010087:Oxides
D000497:Alloys; D002858:Chromium Alloys; D016876:Metal Ceramic Alloys; D010087:Oxides; D003776:Dental Porcelain; D009532:Nickel