| 摘要 |
1,140,943. Switch contacts. SIEMENSSCHUCKERTWERKE A.G. 1 April, 1966 [1 April, 1965], No. 14705/66. Heading H1N. [Also in Division C7] A sintered metal compact such as an electrical contact e.g. a switch pin or a tulip shaped switch is made by compacting at least two layers of metal powder consisting of at least one of W, Mo and Re, the compacting pressure of the layers being different when adjacent layers are of the same composition, sintering the compact and then impregnating with Ag or Cu or their alloys. When the layers are of different composition the compacting pressure may be the same for each layer. As shown in Fig. 1d a metal powder layer 3 is first compacted in the die 1, a second layer 5 is then compacted at a lower pressure followed by layers 7 and 9, the shape of the layers being determined by the movable top punch. Each pressed layer may have its upper surface loosened or roughened prior to the introduction of the next powder layer. After sintering impregnation with Cu or Ag is carried out in a graphite or ceramic mould. The following systems may be made: W-Cu; W-Ag; Mo-Cu; Mo-Ag; W-Mo-Ag; Re-Cu; Re-Ag. The system M 1 -M 2 -M 3 in which M 1 is W, Mo or Re, M 2 is Cu or Ag or their alloys and M 3 is Ni, Fe, Co or Cr may also be produced. |
