Martensite-type transformations in platinum alloys

Depending on the martensitic transformation temperatures and mechanical properties, alloys exhibiting this phenomenon can have a wide range of applications. Such transformations are known to exist in the platinum system. Platinum–iron is reported to exhibit a martensitic transformation, for example, from a disordered fcc (face-centred cubic) to a bcc (body-centred cubic), or from an ordered fcc to a bct (body-centred tetragonal) structure. The transformation temperature is usually in the range 30 to 300°C. A martensite-type transformation has also been observed in platinum–titanium, where a B2 (ordered bcc) to B19 (orthorhombic) transformation occurs, with the transformation temperature in the region of 1000–1070°C. Martensite transformations have been observed in other platinum systems, such as platinum–gallium and platinum–aluminium. This paper describes martensitic-type transformations in the platinum–titanium system.