GB602857A - Improvements in and relating to overlay metals of aluminium or aluminium base alloy bonded to an iron group metal, or metal base alloy - Google Patents

Abstract

602,857. Making compound sheets and bearings. MALLORY METALLURGICAL PRODUCTS, Ltd. April 2, 1946, Nos. 10177 and 10178. Convention dates, Oct. 7, 1944, and Feb. 27, 1945. [Classes 83 (ii) and 83 (iv)] [Also in Group XXXVI] Soldering.-A method of bonding together aluminium or aluminium base alloy and an iron group metal or iron group base alloy consists in interposing a layer or layers of silver between the metals and applying heat and pressure to bond them together. An iron group metal is defined as iron, nickel or cobalt. In one method, strips of sheet steel and aluminium 10, 13, Fig. 1, are unwound from rolls 11, 14, passed through electroplating apparatus 12, 15 in which the strips are plated with silver on one side (see Group XXXVI) and the two plated surfaces are then brought together and the superposed strips are heated to between 350- 500‹ C. in a hydrogen furnace 16 and then passed between pressure rolls 18, 19 in a hydrogen chamber 17. The total thickness of the silver layers is preferably between 0.0003 to 0.006 inch. In a modified form, the steel strip alone is silver plated, the surface of the aluminium being thoroughly cleaned. In another modification, Fig. 2, aluminium and steel plates 26, 28 with their silver coatings 27, 29 are stacked between the pressure plates 21, 22 of a hydraulic press together with carbon plates 25, 30 and plates 23, 31 carrying induction heating coils 24, 32. Alternatively, the plates may be heated by a hydrogen flame or by resistance heating coils. The assembly is enclosed in a hydrogen filled hood 33. After bonding, the slab may be rolled down to the required thickness. The plated aluminium sheet may be placed in a plated recess in the steel sheet. Fig. 4 shows an I-section steel member silver plated at 40, into the grooves of which are placed aluminium slabs 41 which may be retained by bending over the edges of the flanges 42. After bonding, the composite slab is rolled to the required thickness.