A hard time without stress for Sandia's diamonds
15 Jan 2000
Diamonds might be a girl's best friend, but they could also be increasingly popular among engineers. Researchers at Sandia National Laboratory in Albuquerque believe they could be the basis for a new generation of wear-resistant coatings that could help extend the life of a variety of industrial equipment.
The Sandia researchers have developed a new method of making diamond coatings that greatly increases their strength and reduces their propensity for peeling away from their substrates. Normally, explain the researchers, the amorphous diamond films used for these purposes contain very high levels of internal stress. The new method, however, creates films with no internal stress.
The technique uses a pulsed laser on a graphite target to deposit a film which has a high proportion of diamond-like bonds but high internal stress. Heating this film causes short-range bond reorganisations which disperse the stress without changing the diamond-hardness of the film. The coatings are wear-resistant, have a low friction coefficient and are resistant to almost all chemicals.
