Tungsten Electrode Enhancement Strategy for High Energy Igniter

High-energy ignition gas discharge tube is mainly used for high-energy igniter, as a switch to control high-energy, mainly used in military aerospace, airborne, missile-borne engine igniter, also can be used in civil ships, boilers, oil fields and other ignition systems. In military high-energy ignition gas discharge tube technology, China has been banned and blocked by western countries for a long time, and can only rely on independent research and development.

The traditional oxide cathode is coated with a layer of alkaline earth metal carbonate on the tungsten surface, which is decomposed to oxides at high temperature. However, the coating is liable to crack or fall off under the action of ions, which affects the service life of the electrode. To solve this problem, researchers have come up with a way to straighten the alkaline earth metal with low work escaping component. The method includes: embargo and blockade, which can only be developed independently.

According to the mass fraction ratio of tungsten to nickel to strontium in the finished tungsten-based electrode material 98.5:0.5:1, the raw materials of tungsten yellow, Ni (NO₃)_2·6H₂O and Sr (NO₃)₂ of the corresponding quality were weighed. The mixed water solution of Ni (NO₃)_2·6H₂O and Sr (NO₃)₂ was obtained by dissolving them completely with deionized water, then the mixed water solution was poured into the kneader, and yellow tungsten powder (level) was obtained. The average particle size is 50 micron) mixed into the above-mentioned mixed water solution, mixing evenly through kneading machine, kneading machine has its own heating system, heating temperature is 90 ℃, until the powder is completely dried to prepare the precursor powder.

The precursor powders were calcined in high temperature resistance furnace (open furnace door) in air at 750 ℃ for 1 h. The calcined powders were reduced in reduction furnace and hydrogen atmosphere at 800 ℃ for 2 h with hydrogen flow rate of 1.0m³/h to obtain doped tungsten powders. The doped tungsten powders were packed and cooled. The tungsten-based electrode material is prepared by isostatic pressing, forming pressure 150 MPa and holding time 20 minutes. The billet is sintered in hydrogen atmosphere at 1580 ℃ and holding time 2 h.

The aim of the above preparation is to improve the resistance to ion bombardment and sputtering of the electrode on the premise of ensuring a good enough emission efficiency, so as to achieve a stable, high-energy and uninterrupted ignition. The service life of high energy ignition gas discharge tube made of tungsten material is longer than that of similar products abroad. It is of great significance to break the restrictions on the export of such products abroad and meet the national defense needs.

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