Platinum Alloys: A Selective Review of the Available Literature

Introduction More than half of the platinum that is produced around the world each year currently fi nds use in automotive and other areas of industry as a catalyst and as a major constituent in various engineering alloys (Figure 1) (1). Platinum also has a place in jewellery manufacturing. The objective of this article is to review the existing phase diagrams and known properties of some platinum alloys that are used in industrial and jewellery applications, and also to present published data on some less used platinum alloys which nevertheless have interesting properties. The alloys covered are of platinum with palladium, iridium, rhodium, ruthenium, gold and nickel. The data on mechanical properties of the platinum alloys presented in Tables I–VII are obtained from the monograph by R. F. Vines (2) published in 1941, still the most comprehensive source, from The PGM Database (3) hosted by Johnson Matthey, and from the internal database and website of Sigmund Cohn Corporation (4), a US pgm alloy fabricator. To keep the uniformity of units of measure all tensile strength (TS) data is presented in psi, and all the hardness data is presented in Vickers hardness (HV) (some of these values are converted from MPa and Brinell respectively). All alloy compositions are given in weight per cent (wt%) unless otherwise specified.