| 摘要 |
<p>PURPOSE:To reduce the thermal capacity of an impregnated type cathode structure body by soldering a porous W on a high melting point metallic plate whose front side has the form same as the rear side of a porous W, and soldering the high melting point metallic plate to a cathode sleeve. CONSTITUTION:A high melting point metallic plate 4 such as W which is processed to make the front side form same as the rear side of a porous W is used. A porous W is soldered to the metallic plate 4, and the metallic plate 4 is soldered to a cathode sleeve 2, with an Mo-Ru solder material in a reducing ambiance at about 2000 deg.C. After that, an oxygen free copper is laid on the porous W, Cu is impregnated in a reducing ambiance at 1500 deg.C, and the surface is machined in a specific size. Even though the porous W layer and the like are processed less than 0.8 mm, no thermal deformation is generated, and a specific property can be obtained. The Cu is removed by maintaining the temperature at about 1600 deg.C in a vacuum. A compound including BaO, CaO, and Al2O3 is melted and impregnated, the excessive impregnant is removed, and a vacuum heat treatment is applied. By such a constitution, no thermal deformation is generated by the minimum thickness of the porous W, and the cathode body structure of a good temperature property with a small thermal capacity can be obtained.</p> |
