Welding breakthrough for manufacturing industry

The materials are fused together using very short pulses of infrared light; the pulses last only a few picoseconds - a picosecond to a second is like a second compared to 30,000 years. To weld the two materials, the laser creates a microplasma - described as a tiny ball of lightning - between them.

The process could have direct applications in the aerospace, defence, optical technology and healthcare fields.

Professor Duncan Hand, Director of the EPSRC Centre for Innovative Manufacturing in Laser-based Production Processes based at Heriot-Watt, said: Traditionally it has been very difficult to weld together dissimilar materials like glass and metal due to their different thermal properties - the high temperatures and highly different thermal expansions involved cause the glass to shatter.

Being able to weld glass and metals together will be a huge step forward in manufacturing and design flexibility.

Various optical materials such as quartz, borosilicate glass and sapphire were all successfully welded to metals like aluminium, titanium and stainless steel using the laser system.

The welds remained intact when tested at -50C and 90C. So we know they are robust enough to cope with extreme conditions,said Professor Hand.