GB1177279A - Sintered Porous Metal Bodies - Google Patents

Abstract

1,177,279. Sintered porous alloys. LOCKHEED AIRCRAFT CORP. April 10, 1967 [April 8, 1966; March 8, 1967], No.16391/67. Heading C7D. A porous sintered metal or alloy containing 0.1- 20% by volume of inert dispersoid particles which are not wetted by the molten metal i.e. the wetting angle is at least 90 degrees, having a density of 30-90% of theoretical and spore channels of diameters of 0À1-25 microns with at least 70% of the channels being inter-connected is made by compacting a powder mixture of the components and sintering at a temperature up to 0À9 of the absolute melting point of the metal component. The metal powder particle size is 0À1-150 microns for pore sizes up to 25 microns and average particle size of the dispersoid should be less than 1/3 of the pore size. The metal and alloys used as examples are; Fe, Ni, stainless steel, Cu-Ni, Co, Cr-B, Si, Ag, Cu, Cu-Al, Al Sn-Al, Sn, Pb, (Registered Trade Mark) #Hastelloy B" Ni-Cr base alloys containing one or more of Al, Ti, Nb, Ta, Mo and W, and a super alloy containing 55% Co-10%Ni-20%Cr-15%W. A large number of suitable dispersoids such as A1 2 O 3 , MgO, ZrO 2 , TiO 2 , WC, B 4 C, TiC, and VB 2 are specified. The powder mixture is compacted by pressing, isostatic moulding, rolling or extruding. The mixture may be formed either by mixing the metal or alloy powder with the dispersoid or by chemical means whereby a decomposable salt of the dispersoid e.g. Th (NO 3 ) is dissolved in a solvent such as methyl alcohol, the metal or metal oxide powder is then mixed with the solution, dried, heated to decompose the salt and then reduced to form the metal. Alternatively a solution of metal and dispersoid salts is polymerized and then oxidized. The oxidized mixture is then reduced.