Published on September 24th, 2012 | by James Ayre0
Metal Surface Developed That Can Self-Repair
September 24th, 2012 by James Ayre
Metal surfaces may soon have the ability to repair themselves thanks to a newly designed ‘coating’ that is filled with tiny lubricant capsules.
A group of researchers from SINTEF and the Norwegian University of Science and Technology (NTNU) have spent most of the last two years developing “ground-breaking expertise in coatings and thermal spraying. The researchers are now testing whether it is possible — where two metal surfaces are in contact with each other — to apply a coating to the surfaces formed of hard particles and capsules filled with liquid lubricant.”
There are many types of machinery that depend on being lubricated at all times — if a leak occurs and causes the moving parts to dry out, that creates huge damage and massive costs to repair. The metal surfaces will grate against each other and eventually seize up, sometimes resulting in the complete junking of the machinery.
As an example, wind turbines have very high maintenance costs — “overhaul of their mechanical components alone accounts for 30 per cent.” And I imagine those costs go up substantially for the offshore wind power market. A technology like this could potentially lead to huge cost savings for wind power providers.
To create the surface, the researchers “apply the lubricant using a thermal spray technique, where powder and capsules are fired at the surface using a flame,” says Sergio Armada of SINTEF Materials and Chemistry. “When the metal surfaces come into contact with each other, the coating is broken down in a controlled manner, releasing the contents of the capsules, and the lubricant will then prevent further friction.”
To test the material, the researchers have done a number of tests using slide bearings in industrial settings, measuring the friction on surfaces with the capsules and without them. “When a coating without capsules was applied to the slide bearing, the friction coefficient was 0.7, while friction was reduced to 0.15 in bearings coated with a layer of capsules.”
The researchers think that this coating also has uses in the medical sector, especially in joint replacements.
Image Credits: SINTEF
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