The Hardening of Platinum Alloys for Potential Jewellery Application

Abstract

Pure platinum is too soft to be used for jewellery and scratches easily. Alloying platinum increases its hardness significantly. However, platinum alloys used in jewellery do need to be easy to work and thus the alloy should be sufficiently soft, but not so soft that their wear resistance is low. A good compromise would be to work with a soft alloy during jewellery manufacture, then harden the alloy so the final finished properties were improved. In order to identify platinum alloys suitable for hardening, platinum with different alloying additions was studied. Platinum alloys with additions of less than 7 wt.% of Ag, Au, Cu, Co, Cr, Fe, Ga, Ge, In, Mg, Mn, Mo, Ni, Si, Sn, Ta, Ti, V, W or Zr were examined, and the merits of each system were assessed for commercial viability. The platinum-titanium system was deemed to show the most promise.

The Effect of Solute Elements on Hardness and Grain Size in Platinum Based Binary Alloys

“…Platinum jewels such as rings, bracelets and necklaces are manufactured by both routs of precision casting and wrought processes. 2,4) In general, jewelry products made by noble metals and alloys are manufactured through various processes such as forming, machining, cutting or polishing. 4) In particular, extremely fine cutting and polishing are the most important to achieve attractive surface appearance in these applications.…”

“…2,4) In general, jewelry products made by noble metals and alloys are manufactured through various processes such as forming, machining, cutting or polishing. 4) In particular, extremely fine cutting and polishing are the most important to achieve attractive surface appearance in these applications. Similarly to other noble pure metals, pure platinum is too soft to accomplish very fine surface appearance by polishing, and it also tends to suffer a surface damage such as scratch or dent during use, deteriorating excellent surface appearance.…”

“…As a result, very few systematic studies have been performed regarding on the effect of alloying elements on various properties in platinumbase alloys in the past. Currently, Biggs et al reported hardening of platinum alloys for jewelry application, 4) and Pt-based intermetallic alloys have been studied with aiming the development of the more superior high temperature material over Ni-based super-alloys. [5][6][7][8] Under these circumstances in platinum alloys, the present study was conducted to investigate systematically the effect of various solute elements on hardness and grain size in platinum-base binary alloys.…”

Platinum-Based Alloys: Investigation of the Effect of Impurities Content on Creep Rate, Rupture Time and Relative Elongation at High Temperatures

“…Interest of researches in platinum based alloys is constantly growing 1 . These types of alloys are used in: glass industry 2,3 , fertilizer plants [4][5][6] , temperature measurement 7 , environment protection 8 , jewelry production 9,10 , shape memory applications 11,12 and medicine…”

Investigation of mechanical and structural characteristics of platinum and palladium at high temperatures

“…Today, platinum alloys, due to their characteristics such as high strength, good workability and mostly corrosion resistance at high temperatures, are present in different areas such as production of glass (Preston, 1960;Fischer, 1992) and nitrogen fertilizers (Ning et al, 1996;Yuantao and Zhengfen, 1999;Trumić et al, 2009), production of thermocouples (Wu and Liu, 1997), production of automotive catalysts (Funabiki et al, 1991), jewelry (Biggs et al, 2005;Wright, 2002) and sensors (González-López et al, 2010). Recently, glucose sensors based on nanoparticles of platinum alloys with Ru, Pd and Au, on the carrier of carbon, have been developed (Xiao et al, 2009).…”