Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Carnegie Mellon U. computational method could speed metallic glass design, testing

31.08.2004


Want a tennis racket that propels balls faster than a race car or a sturdy ship hull that never rusts? Finding the recipes for such remarkable materials – called amorphous metals – should be easier using a new computational approach developed by Carnegie Mellon University physicist Michael Widom.



Described in an upcoming issue of Phys. Rev. B (September 1, 2004), this method already has been used to virtually generate recipes for more than 1,700 structures, many of which have never before been analyzed. The novel approach should prove valuable in guiding future bench testing and sparing countless hours of laboratory trial and error to generate amorphous metals.

Alloys for everyday materials like stainless steel are made by combining a metal with other elements. The resulting metals crystallize into lattices in which atoms line up in orderly arrangements. Defects in these crystals inevitably weaken materials made from them, leading to fractures and corrosion.


Amorphous metals, otherwise known as metallic glass, lack these defects because they are disordered materials essentially frozen in place. Consequently, they display remarkable corrosion resistance, strength and elasticity – the “spring-like” property coveted by tennis and golf champions.

Despite their promise, only small quantities of metallic glass have been generated to date because heated alloys require rapid cooling to freeze a glass into place. Quick, uniform cooling of a large quantity of material is difficult, given that elements like to combine with one another in energetically favorable combinations, resulting in impurities that crystallize in an amorphous glass as it cools.

Using the new computational method, developed by Widom, scientists now can virtually predict what structures will crystallize out of an amorphous metal as it cools and how “spicing” a mixture with new elements prevents the emergence of these impurities.

Widom and his colleagues, including Yang Wang from the Pittsburgh Supercomputing Center, Marek Mihalkovic from the Slovakian Academy of Sciences and Don Nicholson from Oak Ridge National Laboratory, used powerful computing to systematically mix different amounts of elements in iron alloys and identify potential metallic glass compositions.

“Our method allows us to calculate energies associated with the formation of stable crystalline structures within these alloys,” said Widom, a professor of physics. These energies reflect the drive different element compositions have to crystallize out of an amorphous glass. “We can identify an unstable mixture to quench into a glass, see what nearby structures are likely to crystallize out, and thwart their formation,” he added.

Given this information, Widom then can virtually add new elements to an alloy recipe and see how they “confuse” the tendency of crystals to form. “Metallic glass is not the most natural state to form as an alloy cools. To make it easy to form glass you want to rearrange things so that the crystalline alternatives are less likely to result,” said Widom. In work to date, Widom already has generated several potential glass alloy mixtures and has shown that “spicing” an iron alloy mixture with a small amount of the large element Yttrium facilitates metallic glass production. Independent laboratory research at University of Virginia and at Oak Ridge National Laboratory confirms this finding. “Ultimately, we would like to identify candidate mixtures that could be cooled in bulk to form novel metallic glasses,” he said.

The new approach is sound, according to Widom, who has used it to propose structures for previously unsolved compounds and also has shown that it generates findings that match experimentally produced results, where they are available.

While this approach is highly promising to study iron-based metallic glasses that could be used in structures such as ship hulls, it also could be used to evaluate metallic glasses made from other alloys. These include aluminum-based mixtures that could yield lightweight, stress-resistant metallic glasses for airplanes.

Lauren Ward | EurekAlert!
Further information:
http://www.cmu.edu

More articles from Process Engineering:

nachricht New technology for mass-production of complex molded composite components
23.01.2017 | Evonik Industries AG

nachricht Etching Microstructures with Lasers
25.10.2016 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>