Language Selection

English French German Italian Portuguese Spanish

Metallic glass: a drop of the hard stuff

Filed under
Sci/Tech

In the past year, researchers have made metallic glass three times stronger than the best industrial steel and 10 times springier. Almost a match for the Terminator, in other words.

Metallic glass sounds like an oxymoron, and in a way it is. It describes a metal alloy with a chaotic structure. While metal atoms normally arrange themselves in ordered arrays, or crystals, the atoms in a metallic glass are a disordered jumble, rather like the atoms in a liquid or a glass. And although strictly speaking a metallic glass isn't a liquid, because the atoms are fixed in place, one company is already marketing the stuff as "liquid metal".

It is the unusual structure that makes metallic glass so promising. In crystalline metal alloys, the atoms are ordered within regions called "grains", and the boundaries between the grains are points of weakness in the material. Metallic glasses, however, have no grain boundaries, so they are much stronger. Hit a crystalline metal with a hammer and it will bend, absorbing some of the energy of the blow by giving way along grain boundaries. But the atoms in an amorphous metal are tightly packed, and easily bounce back to their original shape after a blow (see Diagram). These materials lack bulky crystalline grains, so they can be shaped into features just 10 nanometres across. And their liquid-like structure means they melt at lower temperatures, and can be moulded nearly as easily as plastics.

No wonder companies are interested. The trouble is, no one was able to make a useful metallic glass until very recently. That is because, when molten alloys are cooled down, they inevitably begin to crystallise, with ordered arrays of atoms growing from various points in the molten liquid. To make a metallic glass, crystallisation needs to be stopped in its tracks. This should happen if a liquid is cooled extremely fast, but just putting a cupful of molten metal into a freezer won't cool it fast enough.

But by pouring molten metal onto a cold, rapidly rotating copper cylinder, one could make sheets of "superfrozen" amorphous metal. The problem was that the sheets he made were only a few nanometres thick. If the rotation of the cylinder is slowed to try to make a thicker sheet it left enough time for crystals to form.

You won't know it to look at them, but before too long many of the metallic parts in everyday products will be the stuff of the Terminator.

Full Story.

More in Tux Machines

Meet Cornelius Schumacher - Akademy Keynote Speaker

At Akademy 2014, outgoing KDE e.V. Board President Cornelius Schumacher will give the community keynote. He has attended every Akademy and has been amazed and inspired at every one of them. If you want more of what KDE can bring to your life, Cornelius's talk is the perfect elixir. Here are glimpses of Cornelius that most of us have never seen. They give a sense of what has made him a successful leader of KDE for several years. Read more

PLASMA ACTIVE PORTED TO KF5

The GSoC might have come to an end, but I am very happy with the progress that we have made porting the Plasma Active to KF5. In my previous blogposts i have describe some of the stuff which they have been ported. So at the moment a lot of the basic features have come back to the Plasma Active, so yes it is at a usable state :) One of the big changes is that Nepomuk has been replaced with Baloo. Despite the fact that a lot of the Nepomuk stuff has been ported, there are still some things left, for example the timeline and tag support on the active-filebrowser. Read more

Mozilla Unveils $33 Intex Cloud FX Smartphone

Mozilla is targeting first time smartphone buyers who haven’t yet upgraded their basic feature phones because of high prices or technology specifications. In an interview with The Wall Street Journal, Jane Hsu, director of product marketing at Mozilla based in Taiwan, explains how the company was able to bring down the cost of smartphones and discusses Mozilla’s future plans. Read more

Appliance maker Electrolux joins IoT-focused AllSeen Alliance

The group is one of the more diverse consortiums, with members ranging from consumer electronics and chipset manufacturers to retailers and service providers. Primarily, work revolves around the AllJoyn open-source framework, which AllSeen said acts as a universal translator for objects and devices to interact. Read more