Preparation method of tungsten-rhenium-based diffusion-type thermionic cathode material containing low melting point barium calcium aluminate salt

A preparation method of a tungsten-rhenium (W—Re)-based diffusion-type cathode material containing barium calcium aluminate salt, comprising:

• step 1, dissolving ammonium paratungstate and ammonium perrhenate in water to obtain a W—Re precursor solution;
• step 2, freeze-drying the W—Re precursor solution to obtain W—Re alloy powder;
• step 3, performing multi-step hydrogen reduction heat treatment on the W—Re alloy powder, followed by pressing to obtain a cathode body;
• step 4, sintering the cathode body to obtain a cathode base;
• step 5, mixing a barium containing compound, a calcium containing compound, an aluminum containing compound and a sintering aid evenly to obtain a mixture, and performing a mechanical mixing method, a hydrothermal method or a co-precipitation method on the mixture to obtain an impregnation salt precursor;
• step 6, drying the impregnation salt precursor, followed by pressing, calcining, and grinding to obtain an impregnation material;
• and
• step 7, embedding the cathode base in the impregnation material, performing a sintering impregnation process on the impregnation material embedded with the cathode base under a hydrogen atmosphere, followed by annealing to obtain the W—Re-based diffusion-type cathode material containing barium calcium aluminate salt.