| 摘要 |
1,135,361. Alloys; powder metallurgy. FANSTEEL METALLURGICAL CORP. June 27, 1967 [June 30, 1966], No. 29616/67. Headings C7A and C7D. Dispersion-hardened Ni/10-30% Cr foil has dispersed therein 0À1-6% by volume of particles of a refractory metal oxide having a free energy of formation at 1, 000‹ C. of more than 100 kilocalories per gram atom of oxygen and an average particle size less than 80 mÁ, the foil being less than 0À01 inch thick and having both (a) elongated grains with a length-to-thickness ratio of more than 2 and a grain thickness of 10-200 Á, and (b) equiaxed grains with an average thickness of 10-80Á and having annealing twins. As described, powder is prepared by co-precipitating Ni and Cr oxides together with colloidal ThO 2 , and the Ni and Cr oxides are then reduced to the metals. The resulting powder is compacted, sintered (in hydrogen), forged or extruded to plate, rolled to sheet at a temperature below the recrystallization temperature, and finally converted to foil by alternately annealing at 1800‹ - 2400‹ F. and cold-rolling. |
