Tarnish testing of a low-gold alloy has been carried out in a solution of Na2S. Different structures were created by means of heat treatments. Substantial variations in tarnish and corrosion resistance and in types of attack were observed. Annealing to a single phase structure gave the best resistance, while subsequent age-hardening had a deteriorating effect.
Get full access to this article
View all access options for this article.
References
1.
ISO Standard 1562, Dental Casting Gold Alloys, 1976.
2.
German, R.M. ; Guzowski, M.M.; and Wright, D.C.: Color and Color Stability as Alloy Design Criteria, J Metals32:20-27, 1980.
3.
Tuccillo, J.J. and Nielsen, J.P.: Observations of Onset of Sulphide Tarnish on Gold-Based Alloys, J Prosthet Dent25:629-637, 1971.
4.
Ingersoll, C. : A Sulphide Tarnish Test for Dental Casting Alloys, IADR Progr & Abst 54:No. 46, 1975.
5.
Status Report on Low-Gold-Content Alloys for Fixed Prostheses, Council on Dental Materials, Instruments, and Equipment, JADA100: 237-240, 1980.
6.
German, R.M. : The Role of Microstructure in the Tarnish of Low-Gold Alloys, Metallography14:253-266, 1981.
7.
Her, H.; Jrgensen, R.; and Srbrden, E.: A Low-Gold Dental Alloy, Structure and Segregations, J Dent Res61:1292-1301, 1982.
8.
McMullin, J.G. and Norton, J.T.: On the Structure of Gold-Silver-Copper Alloys, Trans AIME185:46-48, 1949.
9.
Raub, E. and Worwag, G.: Über Gold-Palladium-Kupfer Legierungen, Z Metallkunde46:119-128, 1955.
10.
Handbook of Chemistry and Physics, 61st ed., Florida: CRC Press, Inc. , 1980-1981, p. 242.
11.
Kaesche, H. : Die Korrosion der Metalle, Berlin; Springer Verlag, 1979, p. 32.
12.
Gellings, P.J. : Introduction to Corrosion Prevention and Control for Engineers, Rotterdam: Delft University Press, 1976, p. 49.
13.
Guertler, W.M. : Konstitution der Ternaren Metallische Systeme, Kompendium-lose-blatt-samlung: I Rieferung 2-3, Berlin : Dahlem, 1956.
