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Tungsten wire is made from doped powders, that is, powders in which small quantities of potassium, silicon, and aluminum have been incorporated.Their purpose is to influence the recrystallized grain structure to reduce the creep rate at the high temperatures of incandescent filaments.The powders are consolidated under high pressure, sintered at high temperatures and worked by rolling and swaging to heavy rod suitable for drawing.Tungsten wire drawing is accomplished by coating the wire with a graphite lubricant, heating to a red heat, and then drawing through tungsten carbide or diamond dies. The process is sometimes referred to as hot cold-working, which means that, while the wire is hot, the temperature is still below the recrystallization range.
Tungsten wire mesh