Other Applications

The versatility of tungsten and its compounds is further highlighted by a few examples:

• Tungsten wire coils, or small boats made of W foil, are used for vacuum metallizing reflector lamps, headlamps reflectors, TV picture tubes and plastics, primarily with aluminium.
• Vapour deposited tungsten oxide layers are functional in self-darkening window panes. Tungsten trioxide is yellow-white and fully transparent in the form of a thin layer. Light converts WO3 to dark blue W20O58 in a reversible reaction, so the light transmission through the pane is reduced in bright sunshine, and the light transmission returns with clouds or at sunset.
• The corrosion resistance of optical glasses can be improved by the addition of tungsten oxide to the molten glass mixture.
• Tungsten shot and ammunition is an environmentally friendly alternative to poisonous lead for hunting and in military training.
• Fishing weights are made of a tungsten weighted plastic to replace the conventional lead weights.