| 摘要 |
574,430. Cathode materials and processing. STANDARD TELEPHONES & CABLES, Ltd. Nov. 19, 1943, No. 19380. Convention date, Nov. 23, 1942. Drawings to Specification. [Class 39 (i)] [Also in Group XXII] To reduce the brittleness of a carburized or thoriated filament or wire, particularly of tungsten, it is flashed, or otherwise heated, in an inert medium such as hydrogen or helium and whilst hot, and whilst still in the medium, it is bent, for example into its final shape. This layer thus becomes " crazed " or shows a finegrained fracture pattern and such surface fractures do not induce deep fractures such as would result in breakage of the filament, particularly if separation occurs between the metal core and the carburized layer. |
