Metallic Glasses, the new wonder material for a world pushing the boundaries. When Titanium is no longer strong enough where do you turn, BMG – Bulk Metallic Glasses – 2.5 times stronger than titanium, but with the pruduction costs of plastic. Cheap tough and very quick to form. Could matallic glass marbles be the toy of the future ?
First discovered by Klement, Willens and Duwez at CalTech – Californian Institute of Technology – in 1960′s . Production of Metal Glass wouldn’t occur until the early 90′s when William L. Johnson and his team were able to develop a commercially viable process. Liquidmetal Technologies was incorporated as a company in 2003 to manage the patents and products including Vitreloy, the first commercially available Metallic Glass.
The findings of their latest research have been published in the May 13, 2011 issue of the journal Science. Established by the research is a new far more efficient production process. They were able to heat small alloy slugs – blanks - at the rate of a million degrees a second. Once heated the metal is injection moulded and cooled. Try doing it all in 40 milliseconds. Sadly it doesn’t pop out of the mould transparent like glass, it’s not transparent metal as the name my imply. The term glass in the name actually refers to the metal having the internal structure of glass -amphorous or random layout of the metal’s atoms – not its transperancy. The crazy internal structure of this metal is its secret.
This next generation of BMG production process is all about speed. The alloy rod is heated to 600 degrees C in a millisecond, then injected into a mould and cooled, with the whole process complete in 40 milliseconds. To heat the alloy rod fast enough ohmic heating was used – firing a short and intense pulse of electrical current into the object to heat. Shock therapy for steel. The whole process is over so fast the metal doesn’t have time to form crytal bonds, it’s still sitting there going ‘what the hell was that?’ The new process is called Rapid Discharge Forming – patents pending - and will be commercialized through Glassimetal Technology, a company formed in 2010 by Johnson and his CalTech alumni. This new process should be able to produce even more perfectly imperfect parts than is currently possible, the speed of the process eliminates any order.
Metallic Glass starts off it’s life as a fairly standard slug of Metal Alloy. Various alloys have been tested over the years some recipe’s increase strength, some effect electrical properties. Vitreloy incredient list includes zirconium and titanium as it’s main ingredients. The same recipe rules that apply to producing any metal apply here just the same. In a sense it’s a new style of forging alloys into products, a new kind of casting. Extremely rapid heating, moulding and cooling.
Metallic Glass’s biggest enemies are crystals and time. As all metals slowly cool the bonds between atoms are reforming into oderly crystal like structures, this is what they naturally want to do and until recenty accepted in metallergy as the strongest way to make metals. The Japanese sumaria sword makers were the masters of this with the heating, folding and cooling cycle while making a sword. Metallic glass takes the opposite approach, it works by making a random structure without any straight lines or points of weakness. Vitreloy is one Metallic Glass product made by LiquidMetals which is twice as strong as titanium. It’s tough stuff but still considered previous generation, one step behind what is discussed in Johnson’s latest research papers.
“We’ve taken the economics of plastic manufacturing and applied it to a metal with superior engineering properties,” Johnson says. “We end up with inexpensive, high-performance, precision net-shape parts made in the same way plastic parts are made—but made of a metal that’s 20 times stronger and stiffer than plastic.”
Is there room in our fast paced world for another wonder material ? Is Metalic Glass destined to be the next Ginshu knife sold on Danoz Direct, or is it a game changer ? The Aeropsace and commercial air craft industries will be all over this technology like a rash, more strength and less weight is their mantra. It may take 10 or 20 years to become established in other areas like manufacturing but BMG’s will be huge. Now has someone seen my transparent aluminium.