GB745511A - Method for the solid-phase bonding of metals - Google Patents

Abstract

745,511. Making composite sheets &c. METALS & CONTROLS CORPORATION. Dec. 31, 1951 [Jan. 5, 1951], No. 30507/51. Classes 83 (2) and 83 (4). Rolling.-A method of bonding two metals comprises heating at least one of them to a temperature above the minimum recrystallization temperature and below both the " hotshort " temperature and the temperature at which a liquid phase or a brittle intermetallic compound would form, pressing the metals together in a protective atmosphere to cause initial bonding and finally heat treating the initially bonded stock to increase the strength of the bond. Metal strips from coils 1 and 3 are passed through pinch rolls 5 or 7 and idler rolls 9 into a furnace 11 from which they emerge through a guide 13 into the pass of a rolling mill 19 which effects an initial bonding of the strips. The pinch rolls impart a tension to the strips as they pass through the furnace. As the strips leave the guide 13 they are pressed down by a weight bar 39. A reducing atmosphere is maintained in the furnace and in the guide 13 and jets of reducing gas may be directed against the edge of the strips between the guide and the mill 19. The temperature of the rolls is greatly below that of the work and they therefore having a chilling effect. It is thought that this treatment causes bonding of the metals at a number of isolated spots. The work is next heat treated to cause a growth of the interfacial bonds, the temperature preferably being above the minimum recrystallization temperature of the metal but below the temperature at which any brittle intermetallic compounds or liquid phase material would form. In an example, strips of fine silver and an alloy known under the Registered Trade Mark " Monel " were cleaned by wire brushes, passed through a furnace heated to 1200‹ F., entered the roll pass at 900-1000‹ F. and were reduced about 32.5 per cent. The rolled strip issued from the mill at about 12 feet per minute and was wound into a coil which was heat treated for about 100 minutes at 1300 ‹ F. For bonding two strips of steel, the furnace temperature was 1500‹ F., the strips entered the roll pass at 1100-1200‹ F. and were reduced 20 per cent. The subsequent heating was for 45 minutes at 1400‹ F. A nickel strip and a steel strip were passed through a furnace heated to 1800‹ F., entered the roll pass at 1400-1500‹ F. and underwent a 46 per cent reduction followed by heat treatment at 1350‹ F. for one hour. A number of curves show the minimum deformation required to bond various metals together at a particular temperature.