Revised phase diagram for the Pt–Ti system from 30 to 60 at.% platinum

Abstract

Alloys of the Ti-Pt system between 30 and 61 at.% Pt were studied using metallography with optical and scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential thermal analysis (DTA). A phase of nominal composition Ti 4 Pt 3 , in the range 41.7-43.4 at.% Pt was found in samples containing between 30 and 47 at.% Pt, and was apparently formed by a peritectoid reaction between ␤-TiPt and Ti 3 Pt at 1205±10 • C. The eutectic reaction between Ti 3 Pt and ␤-TiPt was found to be at ∼35 at.% Pt and 1424±10 • C, and the Ti 3 Pt phase melted at circa 1500 • C. The other phase boundaries agreed with the published literature, except that a slightly wider range was found at 1200 • C for ␤-TiPt.

First-principles studies of structural stabilities and enthalpies of formation of refractory intermetallics: TM and TM3 (T = Ti, Zr, Hf; M = Ru, Rh, Pd, Os, Ir, Pt)

“…At high temperature, all these three compounds were reported to have the B2 structure [32,37,42,44,60]. Our calculations ( Table 2) confirm the observed trends of ground state phase stability: the B33 and B19 phases are equally stable for TiPt, whereas the B33 is the most stable phase for both ZrPt and HfPt (with a large energy difference between the B33 and B19 phases).…”

Band engineering in silicide alloys

“…Considering just these three compounds (not including higher order silicides and titanides) the heats of formation indicate that upon heating the Ti/Pt/Si system, PtTi or TiSi would form first. TiPt n alloys are indeed well known experimentally [31,32]. The formation of PtSi, Ti x Pt y Si z or Ti x Pt 1-x Si compounds would occur at higher temperature.…”

Thermodynamic assessment of the Pt–Ti system

“…However, the compounds Ti 3 Pt, TiPt and ␥, optimized as strict stoichiometric compounds by Murray [7], exhibit the homogeneity ranges between 22 and 29 at.% Pt, 46 and 54 at.% Pt, and 75 and 81 at.% Pt, respectively. In 2004, Biggs et al [8] the purpose of this work is to re-assess the Pt-Ti system thermodynamically, while considering the stoichiometry of Ti 4 Pt 3 and TiPt 8 and the homogeneity ranges of Ti 3 Pt, ␣TiPt, ␤TiPt and ␥ phases. Nishimura and Hiramatsu [6] undertook the most comprehensive study of the Pt-Ti phase diagram, using metallography, X-ray analysis and differential thermal analysis (DTA).…”

“…Nishimura and Hiramatsu [6] undertook the most comprehensive study of the Pt-Ti phase diagram, using metallography, X-ray analysis and differential thermal analysis (DTA). Nishimura and Hiramatsu [6] found three intermetallic phases: Ti 3 Pt, TiPt and TiPt 3 , which they reported as melting congruently at the respective temperatures of 1643, 2103 and 2223 K. Biggs et al [8] determined the alloys of the Pt-Ti system between 30 and 61 at.% Pt using metallography with optical and scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential thermal analysis. The intermetallic phase Ti 3 Pt was found to melt at 1773 K [8], not 1643 K as previously reported by Nishimura and Hiramatsu [6].…”