GB1340076A - Dispersion strengthening of platinum group metals platinum group metal based alloys gold and gold based alloys - Google Patents

Abstract

1340076 Dispersion strengthened metals and alloys by granulating metals JOHNSON MATTHEY & CO Ltd 18 Jan 1971 [23 Jan 1970] 3425/70 Headings C7D and C7X A Pt group metal or alloy thereof or Au or Au based alloy in dispersion strengthened by alloying the metal or alloy with a minor amount of an additive material capable of forming a stable refractory compound, in particular an oxide, converting the alloy thus formed into granules or powder, cold working the granules or powder exposing the deformed granules or particles to a gas at a temperature to form said stable refractory compound within the alloy and compacting and sintering the treated granules or particles. The additive material may comprise any of the following: Be, Mg, Al, Si, Th, U, Ca, Se, Ti, V, Cr, Mn, Sr, Y, Zr, Nb, Ba, the rare earths, Hf and Ta, the preferred one being Zr which may be added to platinum or an Pt-Rh alloy in the range 0À05-5À0 wt per cent. The alloy is preferably converted into granules by flame spraying a wire formed of the alloy into distilled water, the resulting granules being formed into flakes in a ball mill and oxidized in air or oxygen at 700‹C. on a silicon support. The compacting and sintering may be repeated and followed by hot forging annealing and cold rolling.