Close-up of a Tungsten Filament Crystal
A light bulb filament slowly sublimes and is slowly oxidized during its use. Grain boundaries between crystals are exposed during the slow oxidation and sublimation of tungsten from the filament. The crystalline unit cell of tungsten is a body-centered cube (BCC).
How are the crystals in this image related the unit cell of tungsten?
To learn more about this process, please go to the Why Does a Light Bulb Burn Out? module on this site.
This image is obtained
with the use of a scanning electron microscope
(SEM). The white regions are areas where electrons