Minuscule shapes sculpted on metal surfaces could have a profound impact in many fields of engineering.
By training intense electron beams on the surface of metals, Bruce Dance and his team have found a way to fashion delicate metal projections that will act like ultra-strong Velcro to form much tougher joints between metals and lightweight composite materials in aircraft and cars.
The projections could be used to encourage bone to grow onto artificial hips. They could also be used in electronics to produce heat sinks of just about any shape.
Developed at the Welding Institute (TWI) in Great Abington, near Cambridge in the UK, the technology - dubbed Surfi-Sculpt - can grow structures up to 2 millimetres high and 0.2 millimetres in diameter.
To make a projection, researchers focus a beam of electrons in a vacuum chamber at the point on a metal surface where they want it to grow. The metal melts at the centre of the beam. When the beam is moved sideways, surface tension pulls the molten metal into a droplet.
And the metal vaporised next to the droplet adds even more metal to the droplet, which then solidifies to start the projection. "When we first realised we could do this we were absolutely gobsmacked," Dance says.
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