GB614598A - An improved composite material suitable for bearings or electrical contact elements and the like - Google Patents

Abstract

614,598. Powder metallurgy. MALLORY METALLURGICAL PRODUCTS, Ltd., and HYDE, C. C. July 17, 1946, No. 21407. [Class 83 (iv)] [Also in Groups V, XXXIV and XXXVII] A bearing, or electric contact, material comprises a body of pressed and sintered powder, the operative face at least of which consists of one part or parts composed wholly of metal and another part or parts composed of a mixture of metal and carbon or graphite. In one form, Fig. 1, the bearing comprises a hollow cylinder with conducting segments 3 of silver alternating with segments 4 composed of a mixture of silver and graphite or carbon and serving to lubricate the bearing. A mould for forming the bearing comprises a cylinder 7 within which fits a spindle 9 with radial vanes 8. The segments thus formed are filled with the powders, the spindle withdrawn and the powder compressed to form a compact which is sintered in a reducing or inert atmosphere. In a modified form, the metal portions may alternate with the graphite containing portions in the axial direction also. The spindle 9 may be rotated as it is withdrawn from the cylinder 7 so that the alternate sections are of spiral formation. Fig. 7 shows an electrical contact member comprising metal sections 13 alternating with mixed metal and graphite sections or strips 14. Instead of silver, the metal parts may be composed of copper, iron, molybdenum, tungsten, tungsten carbide or mixtures of two or more of these metals with or without the addition of silver. The metal and carbon mixture preferably comprises 95 per cent silver and 5 per cent graphite. Specification 539,996 is referred to.