Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. The name tungsten comes from the former Swedish name for the tungstate mineral scheelite, tung sten or “heavy stone”, most important properties for tungsten is high melting point and high density. Meanwhile, the hardness is high and it’s quite fragile compare to other refractory metals. All the properties make tungsten metal hard to be machined, here we will introduce the machining process for tungsten rod, wire, and bar.
After sintering, the tungsten blank will be forged, to make a higher density and better mechanical properties.
Process for tungsten rod from blank: Spin forging and drawing several times a suitable ingot, repeated annealing is necessary during the several times of drawing, it might be broken when drawing if not annealed. Mold is engaged in the process in order to draw to desired diameter. Remove the oxide surface, graphite is used as lubricant, this step will also remove it from the surface of rod. Regular surface treatment is grinding or finish turning, to make sure the tolerance and surface roughness in good range.
