Synthesis and characterization of nano-brazing alloy for thermionic dispenser cathode application

Abstract

Development of thermionic cathode for use in vacuum electron devices is very much critical due to high-temperature operation. Brazing of the porous tungsten cathode button and molybdenum sleeve, puts the challenge of using a suitable braze material. The paper describes synthesis of a brazing alloy based on nano-composites of Mo–Ru–Ni. The synthesized powder was analyzed by Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy. The spreading/wettability, flowability, and melting characteristics of the synthesized nano-powder have been found superior to those of its mechanically mixed variant.

Keywords:

• High-temperature brazing
• sol–gel synthesis
• Scanning Electron Microscope (SEM)
• Energy Dispersive Spectroscopy (EDS)