Barium Tungsten Electrode Manufacturing Process
Maunfacturing process of barium tungsten electrode is impregnated method. The advantages of this method of making an electrode include: good emission properties, high current density, smooth appearance and long product life time. But the process is more complex and more difficult. To prepare impregnated Ba-W electrode must have two elements: tungsten cavernous and emissive material.
Tungsten Cavernous:
1. The melting point should be high, evaporation rate is small, the vapor pressure is low, higher mechanical strength, expansion coefficient is small, the resistivity is large.
2. The formula: W (250 mesh/cm2) 97g, paraffin 3g.
3. Function: lubricating, bonding, holding hole. Gasoline (aviation gasoline) 30 ~ 40cc + glycerol.
4. Process:
(1) Poure gasoline → paraffin (to make it melt) is poured into → tungsten powder (about 180℃) → rapid stirring, until gasoline cannot be smelt → sieving → 75 ~ 80 mesh/cm2 → pressing → box (or the shape of direct requests) pressure 2T/cm2.
(2) Low-temperature sintering (deparaffinized, to maintain a certain hardness, slow heating at 600℃ prior to 100 ~ 150℃/h. When it reaches 600 ~ 1400℃, 200℃/h (1 hour incubation) directly mold to burn 1700℃.
(3) Sintering temperature at 2000℃ (about half an hour) emitting material in vacuum resistance furnace.
Emissive Material:
1. Barium Aluminate:
Melting point is 1600℃ (impregnation temperature 1700℃ ~ 1750℃), put it in oven → grinding → pressed into blocks → add the Al2O3 to the molybdenum boat (BaCO3·CaCO3 decomposition), 700 ~ 800℃ incubated for 1 hour, 800 ~ 900℃ for 1 hour, 1400℃ for 2 hours → finished product.
2. Barium Zirconate: Mix powders and distilled or deionized water to form a spherical shape, and then put it in furnace for sintering, grinding, mesh screening to 80~75 mesh/cm2.
If there is any interest in tungsten electrode, please feel free to contact us through the following methods.
Email: sales@chinatungsten.com
Tel.: +86 592 512 9696/+86 592 512 9595
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