| 摘要 |
1339965 Impregnating sintered bodies with metal SIEMENS A G 19 April 1971 [26 March 1970] 25315/71 Heading C7D [Also in Division H1] A material suitable for use as a contact material for vacuum switches is made by providing a sintered metal body having its pores impregnated with a metal of lower melting point, and introducing a metal having a high vapour pressure into said body by liquid diffusion at a temperature lower than the melting point of said lower melting metal by using an auxiliary metal which forms a liquid phase with the lower melting metal and the metal having a high vapour pressure. The quantities of metal and other parameters are such that the auxiliary metal and the metal having a high vapour pressure penetrate only partially into the impregnated sintered body. The sintered body may be made of W, Mo or Re and may be impregnated with Ag or Cu or alloys thereof. Suitable metals having a high vapour pressure are Bi, Pb, Ga and Te and suitable auxiliary metals include Ag, Mg, Si, Cu, Sb, Zn and Cd. In an example by tungsten particles having a size of < 60 Ám are sintered at 1600‹C under a pressure of 2À5 Mp/Cm<SP>2</SP>, and then impregnated with Cu at 1200‹C under hydrogen. A mixture of Ag powder and Bi powder is impregnated at 1000‹ C V the Cu Ag Bi layer formed is machined off to leave a product consisting of a layer of W Cu Ag Bi above a layer of WCu above a layer of Cu 6. In another example, Mo is used to form the sintered body. |
