| 摘要 |
1,177,558. Brazing. GREAT LAKES CARBON CORP. 19 Dec., 1967 [28 Dec., 1966], No. 57711/67. Heading B3R. [Also in Divisions C7 and H2] Contact resistance between engaged threaded portions of a conductor bar 6, e.g. of copper, aluminium, steel or carbon and a carbon body in the form of a graphite plate or pins 3, is lessened by interposing between the threads a molten alloy 4 of the kind which expands on solidification and which has a melting-point between 95‹ and 300‹ C. The conductor 6 is mechanically and/or chemically cleaned and the threaded recess of the carbon body is cleaned by compressed air. The molten alloy is poured in the recess of the body 3, which is heated above the melting-point of the alloy and the bar 6 is threaded into the recess so that the molten alloy rises between the threads. Alternatively, pellets or powder of the alloy may be deposited at the bottom of the recess and the temperature of the assembly is raised above the said melting-point. When the carbon body is a plate, the areas adjacent to the recess are reinforced with graphite or carbon strips or by a thick layer of material left during machining. The end 5 of the carbon body in use is connected to an anode plate of an electrolytic cell, e.g. a mercury-cathode chloroalkali cell. Alternatively, a carbon pin may be externally threaded for engagement in a threaded recess in a conductor body. Examples of suitable alloys are: 58 Bi, 42 Sn; 55À5 Bi, 44À5 Pb; 48 Bi, 28À5 Pb, 14À5 Sn, 9 Sb; 15 Sb, 58 Pb, 26 Sn, 1 Cu; 15 Sb, 82 Pb, 3 Sn. |
