Tungsten heater materials

Tungsten heater materials

The most important heater material is tungsten. In tungsten's natural formis usually obtained from the minerals wolframite (Fe, Mn) WO4 and schoelite (CaWO4). Because 70% of our original tungsten resources have been depleted, methods have been found for purifying relatively poor-grade ores. 

The quality of tungsten heater wire depends upon many factors, and the materials and manufacturing process are carefully controlled. The powder used to produce the ductile metal is initially of high purity. For the purposes of inhibiting grain growth, however, very small quantities of partly volatile alkali silicates and non-volatile oxides such as silica, alumina, thoria, or calcia are added to the tungsten powder.