GB773722A - Improvements in composite bearing strips and the manufacture thereof - Google Patents

Abstract

773,722. Making composite bearings; powder metallurgy. BOHN ALUMINUM-BRASS CORPORATION. June 7, 1955 [July 2, 1954], No. 16394/55. Classes 83 (2) and 83 (4). A method of making a composite bearing strip comprises placing a layer C<SP>1</SP> of commercially pure aluminium on a steel backing strip A and bonding them together by heat and pressure, depositing a second layer G<SP>1</SP> of comminuted tin and aluminium and sintering by heat and compression to densify the comminuted layer and also to strengthen the bond between layers. In a preferred embodiment low carbon cold-rolled steel strip which has been chemically cleansed and electro-plated with nickel is drawn from a coil A and passed through flattening rolls B. An applicator C deposits a layer C<SP>1</SP> of comminuted commercially pure aluminium on the nickel surface, which is sintered in an electric furnace D having a non-oxidizing atmosphere at 1150‹ F. The strip then passes through heated rolls E to densify the sintered layer and increase the strength of its bond with the backing strip and a wire brush F removes the oxide film therefrom. A second applicator G deposits a layer G<SP>1</SP> of mixed aluminium powder and tin, preferably containing from 10 to 20 per cent of tin and the strip passes through a second electric furnace H having a non-oxidizing atmosphere where it is heated to 400‹ F. and remains for 20 to 30 minutes. The strip then passes through another set of rolls 1. The aluminiumtin powder may also contain small quantities of iron, copper, lead, nickel, silicon, magnesium, manganese, antimony or zinc, and this powder may have its constituents thereof in separate particles or it may be a powder of the alloy. The pure aluminium layer may alternatively comprise an aluminium strip which is bonded directly to the nickel-plated surface of the steel backing-strip.