| 摘要 |
1,223,043. Dispersion.hardened alloy made by powder metallurgy. FANSTEEL Inc. May 20, 1968 [May 24, 1967], No.23817/68. Heading C7A and C7D. An alloy in which at least 50% of the metal constituents is an iron group metal and 10-35% Cr also contains 0À1-10% by volume of uniformly dispersed discrete refractory oxide particles having a free energy of formation at 1000‹ C. greater than 102 Cals/gm. atom of oxygen and is made by blending a) one part of an oxide dispersion hardened iron group metal, the oxide particles having a number average particle size of 3-50 millimicron with b) 0À11-0À54 parts of a metal powder containing at least 60% Cr with at least 95% of the powder particles being smaller than 20 microns; milling the mixture until at least 95% thereof is less than 5 microns; compacting the mixture; and working and heating the compact for homogenization. The iron group metal may be Fe, Co or Ni; the oxide may be of Al, Ce, Hf, U, Mg, Th, Be, La, Ca or Y; the final body may contain up to 0.3% free oxygen (i.e. not in the refractory oxide); powder a) may contain up to 20% Mn and/or up to 30% Mo and/or W; and powder b) may contain up to 40% in total of one or more of Ti, V, Al, Si, Zr, Mg, Nb and Y. The compact may be sintered in dry hydrogen and may be worked by swaging, forging, extrusion or rolling. |
