scholarly journals New white gold alloys

Gold Bulletin ◽  
1981 ◽  
Vol 14 (1) ◽  
pp. 19-24 ◽  
Author(s):  
I. Bruce MacCormack ◽  
John E. Bowers
Keyword(s):  
Gold Bulletin ◽  
1978 ◽  
Vol 11 (2) ◽  
pp. 35-39 ◽  
Author(s):  
Grahame P. O’Connor
Keyword(s):  

Author(s):  
Ulrich E. Klotz ◽  
Tiziana Heiss ◽  
Teresa Fryé

A series of iterative wear and corrosion tests were conducted on two 950 platinum alloys, two 585 white gold alloys, and two 750 white gold alloys. Testing followed standardized industrial procedures in order to provide comparable and reproducible conditions. Wear testing comprised a sequence including abrasion testing, corrosion testing, and polish testing. Mass loss was recorded after each test cycle. Five complete test cycles were followed by two long-term polish tests. The total testing time was ca. 250h. A pronounced difference in the mass and volume loss between the platinum and the gold alloys was observed. The absolute volume loss per surface area of the platinum alloys was a factor of two to three times lower than that of the gold alloys. The highest volume loss was observed for 750 AuPd, followed by 585 AuPd, 585 AuNi and 750 AuNi with the latter three showing similar wear behaviours. The mass loss increased linearly with testing time. No measurable mass loss was observed by corrosion testing in our limited duration test cycle and the only alloy exhibiting significant corrosion was 585 AuNi. Hardness of the alloys was determined by Vickers microhardness testing at a 100g load. Notably, higher hardness levels were not found to be an indicator for low mass or volume loss.


2004 ◽  
Vol 12 (3) ◽  
pp. 327-332 ◽  
Author(s):  
L. Battezzati ◽  
I. Moiraghi ◽  
I. Calliari ◽  
M. Dabalà
Keyword(s):  

Gold Bulletin ◽  
2005 ◽  
Vol 38 (2) ◽  
pp. 55-67 ◽  
Author(s):  
Steven Henderson ◽  
Dippal Manchanda
Keyword(s):  

2020 ◽  
Vol 58 (7) ◽  
pp. 447-452
Author(s):  
Ikgyu Kim ◽  
Kwangbae Kim ◽  
Ohsung Song

A stripping solution with thiourea, iron(III) sulfate, and sodium dodecyl sulfate(SDS) was employed to strip Ni-based 14 karat white gold alloys, and the formation of the NiS byproduct and elimination of passivation were investigated in the presence of 0.0-0.2 g/L SDS. White gold alloy samples with a flat shape were cast by gypsum investment and were stripped using the prepared stripping solution. Subsequently, the surface morphology, elimination of the passivation layer, weight loss, microstructure, elemental composition, and electrochemical properties of the samples were analyzed by optical microscopy, Raman spectroscopy, precision scale, scanning electron microscopy, energy dispersive X-ray spectroscopy, and linear sweep voltammetry, respectively. It was found that passivation layers of the as-cast samples were removed by the suggested stripping solution. Upon the addition of SDS, the stripped sample showed a bright silver color without NiS, while the sample showed a dark tarnished appearance due to NiS formation without SDS. The weight loss ratio decreased with increasing SDS content and stabilized at 0.2 % for SDS concentrations exceeding 0.15 g/L, and the sample showed a uniformly etched microstructure. EDS results showed that NiS was formed without SDS addition, while linear sweep voltammetry results indicated that NiS formation was restrained upon SDS addition because SDS suppresses the formation of formamidine disulfide from thiourea. Thus, the suggested thiourea stripping with SDS addition was successfully applied to Ni-based 14 karat white gold alloys.


2004 ◽  
Vol 8 (3) ◽  
pp. 147-158 ◽  
Author(s):  
Benedetto Bozzini ◽  
Pietro Luigi Cavallotti ◽  
Ameriga Fanigliulo ◽  
Giuseppe Giovannelli ◽  
Claudio Mele ◽  
...  

2020 ◽  
pp. 55-63
Author(s):  
S. B. Sidelnikov ◽  
◽  
Y. D. Ditkovskaya ◽  
E. S. Lopatina ◽  
O. S. Lebedeva ◽  
...  

2012 ◽  
Vol 476-478 ◽  
pp. 89-93 ◽  
Author(s):  
Hao Hua Zeng ◽  
Xiong Zhi Xiang ◽  
Su Mei Lei

A method to estimate the thermodynamic properties of Multi- component white gold alloys from those of constitutive binary alloys was proposed. The Miedema's theory and Chou model. were used to calculate the formation enthalpies of Au–Cu–Ag-Zn-RE alloys. The agreement between the calculation and experiment is reasonable. Formation enthalpies of Au–Cu–Ni-Zn-RE and relative stability of their intermetallic compounds were predicted with present method.


2011 ◽  
Vol 66-68 ◽  
pp. 1494-1499
Author(s):  
Xiong Zhi Xiang ◽  
Xiao Jun Bai ◽  
You Zheng Tang ◽  
Fei Niu

In this paper, Au-Zn-Cu-Ni alloy series was take as a benchmark. Nickel element was replaced by Manganese in different ratios. The existing state and distribution law of Manganese, and the effects of the Manganese on microstructure and properties of gold alloys were studied. The mechanism of effects of Manganese on the colour and the release of nickel of gold alloys were discussed.


2009 ◽  
Vol 521-522 ◽  
pp. 52-54 ◽  
Author(s):  
I. Tkalcec ◽  
J. Hennig ◽  
D. Mari ◽  
R. Schaller

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