| 摘要 |
This invention provides a method of welding an electric feedthrough assembly for an electric lamp. The feedthrough assembly comprises at least a plug and an electrode pin, each being formed from an electrically conductive refractory material, such as a molybdenum-titanium-nickel plug and a tungsten electrode pin. In a preferred embodiment of the invention, the electrode pin is inserted into a chuck of a drill press. The plug is placed on a rubber pad with the cavity in the plug aligned under the electrode pin. The electrode pin is rotated and pressed into the cavity with increasing pressure until the plug commences rotating on the rubber pad. Substantial heat is generated within the cavity by friction between the rotating electrode pin and the stationary surface of the plug within the cavity. As the pressure is increased on the electrode pin, intimate contact between the materials is attained. The materials melt at the surfaces where friction occurs; the coefficient of friction in fluid decreases; production of heat ceases; the molten materials cool and fuse together whereupon the plug commences rotating. The rubber pad inhibits rotation of the plug only when the torque on the plug is less than a threshold value, i.e., prior to fusion of the plug and electrode pin.
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