GB1163766A - Process for Forming Sintered Metal Coatings - Google Patents

Abstract

1,163,766. Sintered metal coatings. TEXAS INSTRUMENTS Inc. Sept. 28, 1966 [Oct.13, 1965] , No.43385/66. Heading C7D. A metal substrate such as strip steel or stainless steel is coated with a slurry of a metal powder and a binder, the slurry is dried, squeezed on the substrate as by rolling with sufficient force to reduce the thickness of the substrate and the layer and then heated to sinter the coating. The metal of the coating may be a single metal, an alloy powder or several metal powders as a mixture and the binder may be polyethylene oxide, methyl-cellulose, non- ionic cellulose ether or polyvinyl pyrrolidone with water or alcohol. The powders specified are Ni, Cu, A1, Fe, Sn, B, Si, Cr or alloys or mixtures of these, the powder size being 15 to 44 microns. As shown in Fig. 1 the slurry 5 is roller coated on to both sides of strip 23, dried in furnace 31, rolled by rolls 41, 43 to a thickness reduction of 10-20% to give a coating density of 90% theoretical. Sintering is effected in furnace 49 the coated base being sintered as a strip or as a coil, the furnace atmosphere being H 2 , N 2 or cracked NH 3 . Further rolling to 20% reduction in thickness is effected by rolls 53, 55. In the case of forming an alloy coating by applying a slurry of mixed powders the sintering after the first rolling is carried out in two stages (see Fig. 4, not shown). In the first sintering stage the temperature is insufficient to cause alloying of the elemental powders and the coating is then rolled to effect e.g. a 40% reduction in thickness. A final sintering is then effected to cause alloying of the powders.