| 摘要 |
PURPOSE:To manufacture a cathode base which can be operated at high current density and at low temperatures by forming an alloy layer from Ir on the surfaces of W powders and uniformly over the whole powders when manufacturing a porous sintered body from W and Ir. CONSTITUTION:W powders having an average grain size of about 0.5 to 8mum and 15 to 25wt.% Ir powders of about -200 mesh are sufficiently crushed and admixed to prepare mixed powders having the Ir powders evenly mixed therein. The mixed powders are granulated by spray dry method using an alcohol/ paraffin solution and pressed at pressures of about 1 to 5ton/cm<2> and temporarily sintered at about 800 to 1300 deg.C in a hydrogen atmosphere and degreased and then sintered for about 1 to 3 hours at about 2000 to 2300 deg.C. Then the Ir forms an alloy layer over the surfaces of the W powders and uniformly over the whole powders, providing a cathode base having stable operation and long-life characteristics. |
