The cathode is tungsten
Supplier — AvekGlob Company — offers tungsten cathodes at an affordable price from the manufacturer. The supplier guarantees the timely delivery of products to any address specified by the consumer /
Tungsten has the highest melting point of all metals, low vapor pressure, low thermal expansion, good thermal conductivity and low electron work. Therefore, tungsten cathodes can withstand temperatures up to 3,200 ° C. They conduct the radiated heat on the anode body and support rods.
The material used to make tungsten cathodes is tungsten-doped lanthanum oxide, or tungsten itself, doped with lanthanum oxide and zirconium. The use of tungsten cathodes improves the environmental safety of installations, since it is a non-radioactive alternative to materials doped with thorium.
As the cathode material, such tungsten grades as WLZ, porous tungsten, WL10 and WVM are used. These materials have an especially high level of thermal stability and are characterized by excellent resistance to arc erosion.
Urgency of application
Tungsten cathodes are used in technologies of powder metallurgy. Their application improves the stability of arc burning (especially at high temperatures), stabilizes electron emission, improves plasticity and thermal conductivity of products. Rational applications are short arc lamps with tungsten rods.
The composition of the tungsten alloy WLZ includes chemically pure tungsten (97.5%), lanthanum oxide La 2 O 3 (2−5%), zirconium oxide ZrO 2 (0.7%), and impurities (not more than 0.03%). The composition of the tungsten alloy WL10 includes chemically pure tungsten (98.9%), lanthanum oxide La 2 O 3 (up to 1.0%) and impurities (no more than 0.1%). The composition of the tungsten alloy WVM includes chemically pure tungsten (99.97%) potassium (0.003… 0.007%) and impurities (no more than 0.02%).
Physical and mechanical properties
Density, kg / m 3 — 19300;
Melting point, 0 С — 3410;
The coefficient of thermal conductivity in the temperature range 20… 500 0 С, W / Mgrad — 17,3;
Specific heat at room temperature, J / kggrad — 317;
The coefficient of thermal expansion in the temperature range 20… 500 0 С, μm / deg — 4,3;
The limit of temporary resistance, MPa — not less than 800… 1100;
Yield strength, MPa — not more than 715;
Relative elongation,% — 0… 1;
Modulus of elasticity, GPa — 417;
Hardness according to Brinell, HB, no more than 488.
Variety and features of use
Tungsten cathodes are supplied in the form of wire and, more rarely, stripes (on individual orders). With an increase in chemical purity, the electrical conductivity of tungsten cathodes increases. Due to the danger of self-ignition, the tolerance for tungsten should not exceed 1 mg / m 3 of air.
Supplier — the company AvekGlob — offers to purchase tungsten cathodes in a wide range. Products can be bought at a price formed on the basis of European and world standards of production. Implementation is possible in bulk and retail, for regular customers, a flexible system of discounts operates.