A team of scientists and Engineers from Heriot-Watt University have welded glass and metal together for the first time using an ultrafast laser system.
The new technique is a breakthrough for the manufacturing industry.
By using very short, picosecond pulses (a picosecond is to a second what a second is to 30,000 years!) of infrared light along the materials the team were able to fuse a range of materials together. The technique allowed them to successfully weld metals like aluminium, titanium and stainless steel to optical materials such as quartz, borosilicate glass and even sapphire.
The new technique could impact everything from aerospace and defence to existing optical technologies and even healthcare.
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 Professor Duncan Hand, director of the five-university EPSRC Centre for Innovative Manufacturing in Laser-based Production Processes based at Heriot-Watt
The new process means that technology can be more flexible in future. Up to now, glass and metal have always been stuck together using glues. These are messy and can move over the lifespan of a product.
How it works?
The new process relies on the incredibly short picosecond pulses from the laser.
Initially, the glass-and-metal are placed in very close contact. The laser is then focused to provide a tight intense spot exactly where the materials meet. The tiny spot allowed the team to reach a megawatt of peak power over an area just a few microns of space.
This creates ‘microplasma’ – a tiny ball of lightning – inside the materials. The tiny scale the team worked at meant the weld was surrounded by a very confined melt area so the materials as a whole are not damaged.
The team have now successfully tested their weld materials at temperatures between -50C to 90C proving their technique can cope with extreme conditions.
Professor Hand and his team are working with a consortium to develop a prototype for the laser processing system and take it closer to commercialisation.
Heriot-Watt University is a teaching and research university based in Edinburgh, established in 1821 as the world’s first Mechanics’ Institute and is the eighth oldest higher education institution in the United Kingdom, it has been a university by Royal Charter since 1966.
