Patent ID: 7993577
Filing Date: 2011-08-09
Classification: B22F,C22C

Abstract:
1. A cost-effective method for manufacturing flat or shaped articles from titanium powder compositions comprising: (a) mixing an underseparated titanium powder manufactured from underseparated titanium sponge, optionally Commercially Pure (C.P.) titanium powder, and titanium hydride powders containing different amounts of hydrogen, and master alloys or elemental alloying powders, in a ratio providing a composition of the required alloy to form a blended composition comprising: (b) compacting the obtained blended composition by die pressing, direct powder rolling, cold isostatic pressing, or metal injection molding at pressures in the range of 400-960 MPa to provide a green compact having a density at least 60% of theoretical density and containing a uniform network of fine pores to accelerate healing during subsequent sintering, wherein said compacting provides additional crushing of brittle hydrogenated titanium particles to reduce pore size and improve the uniformity of pore distribution, thereby promoting the subsequent sintering temperatures of said green compacts whereby an increased hydrogen content is retained in the green compact in order to provide emission of hydrogen and a high hydrogen partial pressure during subsequent chemical cleaning and sintering steps, (c) chemical cleaning and refining said green compact by heating to 300-900° C. and holding the green compact at such temperatures for at least 30 minutes thereby reacting chlorine, magnesium, oxygen, and other impurities with hydrogen emitted through decomposition of titanium hydride in the green compact, whereby an increased partial pressure of hydrogen up to 10 (d) heating the cleaned and refined green compact in vacuum at a temperature range of 1000-1350° C. and holding such temperature for at least 30 minutes, thereby sintering the β-phase of titanium to form a sintered compact, and (e) cooling the sintered compact to form a flat or shaped article.