Platinum alloys based on Pt–Pt3Al for ultra-high temperature use

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2002-06, Vol.329-331, p.295-304
• Main Authors: Hill, P.J, Adams, N, Biggs, T, Ellis, P, Hohls, J, Taylor, S.S, Wolff, I.M
• Format: Article
• Language: English
• ISSN: 0921-5093
• DOI: 10.1016/S0921-5093(01)01577-5

Platinum-aluminium alloys based on the L1 sub 2 compound Pt3Al have potential as high-strength alloys with superior environmental resistance at ultra-high temperatures. Two-phase microstructures, analogous to the nickel-base superalloys, and consisting of the intermetallic compound Pt3Al and the (Pt) solid solution, can be engineered to have the attributes of microstructural stability, environmental resistance, high-temperature strength and room-temperature ductility, Pt3Al exists as a tetragonal phase below 1290 C, and ternary alloying is employed both to stabilize the L1 sub 2 crystal form of Pt3Al and as a solid-solution strengthener of the (Pt) phase. In this investigation, the phase relations of the Pt-rich comers of eight Pt-Al-X ternary systems (X = Ru, Re, W, Mo, Ni, Ti, Ta and Cr) are characterized. The solubility of element X in (Pt) and Pt3Al, and the effect on the phase boundaries, was assessed using SEM-EDS. XRD was used to assess which crystal variant of Pt3Al was stabilized. Preliminary room-temperature mechanical testing was carried out on the alloys. This assessment has been used to select the most promising systems for further characterization.