Study of Pt-Al-Nb alloys above 45 at.% Pt

0538942 - FZÚ 2021 RIV US eng J - Journal Article
Ndlovu, G. F. - Ukabhai, K. D. - Nape, K. T. - Samal, Sneha Manjaree - Wookey, G. - Douglas, A. - Julies, B. A. - Joja, B. - Cornish, L. A.
Study of Pt-Al-Nb alloys above 45 at.% Pt.
Journal of Phase Equilibria and Diffusion. Roč. 41, č. 4 (2020), s. 391-417. ISSN 1547-7037. E-ISSN 1863-7345
Institutional support: RVO:68378271
Keywords : experimental phase equilibria * liquidus surface * phase diagram * platinum * ternary phase diagram
OECD category: Materials engineering
Impact factor: 1.468, year: 2020
Method of publishing: Limited access
https://doi.org/10.1007/s11669-020-00798-1

Pt-Al-Nb alloys were made by arc melting and studied in both the as-cast condition and after annealing at 1000 C for 1000 h, using scanning electron microscopy with energy dispersive x-ray analysis, and x-ray diffraction. A modified electro-etching method was used to etch as-cast alloys which gave much clearer microstructures, by helping to remove the Al oxide scale on the surface. One ternary phase was found, Nb47.8Pt50.3Al1.9 (at.%). A solidification projection, liquidus projection surface and 1000 C isothermal section were derived. The extensions into the ternary on solidification were: *Nb2Pt: * 20 at.% Al, *NbPt2: * 5 at.% Al, bNbPt3: * 4 at.% Al, *PtAl: * 2 at.% Nb, *Pt5Al3: * 5 at.% Nb, *Pt3Al: * 10 at.% Nb and b: * 30 at.% Nb. Ten invariant reactions were found on the liquidus surface. The samples were annealed at 1000 C for 1000 h under air, and while some alloys showed phases with little reduction in extension, some alloys had oxidised to form (Pt) and the oxides of aluminium and niobium.

Permanent Link: http://hdl.handle.net/11104/0316918