The development of platinum-based alloys and their thermodynamic database

Abstract

A series of quaternary platinum-based alloys have been demonstrated to exhibit the same two-phase structure as Ni-based superalloys and showed good mechanical properties. The properties of ternary alloys were a good indication that the quaternary alloys, with their better microstructure, will be even better. The quaternary alloy composition has been optimised at Pt84:Al11:Ru2:Cr3 for the best microstructure and hardness. Work has begun on establishing a thermodynamic database for Pt-Al-Ru-Cr alloys, and further work will be done to enhance the mechanical and oxidation properties of the alloys by adding small amounts of other elements to the base composition of Pt84:Al11:Ru2:Cr3

On the development and investigation of quaternary Pt-based superalloys with Ni additions

“…In this context, high melting platinum group metals Ir, Rh, and Pt are of rising interest for very high-temperature applications. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] A small number of research groups worldwide try to copy the highly successful strengthening mechanism of Ni-based superalloys in new high-temperature materials based on platinum group metals. Drs.…”

“…Although pure Pt melts already at 1772 °C, excellent high-temperature corrosion and oxidation resistance make it a promising candidate to serve as a base for a new family of superalloys. Research groups in South Africa [11][12][13][14][15][16][17][18][19] and Germany [1,11,20] are investigating refractory superalloys based on the system Pt-Al. On the Pt-rich side of the Pt-Al system, the intermetallic phase Pt 3 Al called ␥Ј is in equilibrium with a fcc Pt-rich solid solution called ␥ (Figure 1(a)).…”

“…[16] Microstructures with small cube-shaped precipitates in a fcc matrix are reported. Cornish et al [11,17] found a two-phase microstructure with fine precipitates embedded in a Pt-rich matrix of an alloy with the composition 84 at. pct Pt-11 at.…”

“…The lattice misfit after aging for 120 hours at 1000 °C was determined to be about Ϫ0.1 pct, i.e., in the same range as in commercial Ni-based superalloys. This article is based on a presentation made in the symposium entitled "Beyond Nickel-Base Superalloys," which took place March [14][15][16][17][18]2004, at the TMS Spring meeting in Charlotte, NC, under the auspices of the SMD-Corrosion and Environmental Effects Committee, the SMD-High Temperature Alloys Committee, the SMD-Mechanical Behavior of Materials Committee, and the SMD-Refractory Metals Committee.…”

High Temperature Corrosion Resistance of Pt-Based Superalloys in 0.2% SO2-N2 Gas

“…The optimum alloy selected for this investigation was based on the quaternary alloy system (Pt-Al-Cr-Ru), and is a fine twophase mixture. Additionally, this alloy yielded the best oxidation properties during isothermal oxidation tests and possesses a reasonable hardness of 472 ± 14 HV 10 [26], compared to other ternary Pt-based alloys, such as Pt 86 :Al 10 :Cr 4 (317HV 10 ) and Pt 86 :Al 10 :Ru 4 (278HV 10 ) [27].…”