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Saturday, 24 January 2015

Printing in Three Dimensions with Graphene GarcíaTuñon 2015 Advanced Materials Wiley Online Library

This innovation could hopfully be the long awaited leap in technology required to bring this marvelous material,graphene, from the realms of dashed dreams fulfill its multiple predicted properties and uses.   Join me in archiving this work and for rapid exploitation. NB. Its Carbon,its abundant, its economic and ecological, (eg. can be obtained from GHG -CO2!



Printing in Three Dimensions with Graphene GarcíaTuñon 2015 Advanced Materials Wiley Online Library

Wednesday, 5 November 2014

Metallic Glass hits the golf ball further and is likely to hit the global market just as hard!

"Throw a rock through a window made of silica glass, and the brittle, insulating oxide pane shatters. But whack a golf ball with a club made of metallic glass—a resilient conductor that looks like metal—and the glass not only stays intact but also may drive the ball farther than conventional clubs. In light of this contrast, the nature of glass seems anything but clear." ref., Phys.org.,newsletter, 0ct.2 014-10-18.



"A new study at the Department of Energy's Oak Ridge National Laboratory, published Sept. 24 in Nature Communications, has cracked one mystery of glass to shed light on the mechanism that triggers its deformation before shattering. The study improves understanding of glassy deformation and may accelerate broader application of metallic glass, a moldable, wear-resistant, magnetically exploitable material that is thrice as strong as the mightiest steel and ten times as springy.
Whereas metals are usually crystalline, metallic glasses are amorphous in atomic structure. Amorphous metals, studied since the 1950s, have a tendency to crystallise when heated, which makes them extremely brittle. Metallic glass alloys that did not crystallise so easily were discovered at Tohoku University and Caltech in 1991 and introduced commercially in golf clubs in 2001."
How materials deform is still high on the research agenda:
"the researchers calculated how atoms move on a personal computer. To describe deformation at the atomic level, they sampled a large number of paths along which a system can evolve. Analysing the ensuing ensemble, they arrived at the statistically likely scenario."
"We unravelled the mystery of this deformation mechanism in not only the metallic  system but also the general amorphous system," Fan said. "It's a challenging randomness problem, but from this huge model statistical result, we find [these two systems] are surprisingly governed by the same mechanism."
"Next the researchers will explore what happens between deformation and shattering. "As a consequence of deformation, next comes the stage where 20 atoms are affected," Egami said. "Sometimes they start an avalanche. Then hundreds of atoms are involved. At the end, all atoms in the system are involved—billions of atoms. So shattering is first started by five and then snowballs into big action."
The researchers' improved fundamental understanding of  creates new knowledge of a material class about which little is known. Such advances may contribute to the USA, federal government's Materials Genome Initiative, launched in 2011 to accelerate discovery, manufacture and deployment of advanced materials for the global marketplace.
Metallurgist and Golfers alike maybe pleased to read more on the topic of Metallic Glasses via links provided by Phys.org.,  and in particular,  Nature Communications. 

Read more at Phys.org 


Three cheers to the metallurgical & mat sci community. Golfers Enjoy.
Original Article Title:

Atomic trigger shatters mystery of how glass deforms:



'via Blog this'

Thursday, 23 October 2014

NOBEL PRIZE AWARDS 2014-blog up dates and links

A longstanding, if not awaited, up-date of my pages was badly needed. This has been done. Unfortunately for me, I was unable to continue using Nobel.org, RSS Feed to capture the information as had been the case up to 2012. This appears to have been abandoned by Nobel.org. Much more effort was required by me, but is now complete. Readers will see the three prizes most relevant to Materials Scientists and Engineers namely: PhysicsChemistry and Economic Sciences. This is in no way an under estimation of two fundamental subjects of huge significance for all humanity and rightly given prominence by Albert Nobel's far-sighted Awards: Peace and Medicine.

Looking forward to reading the Prize Winners Lectures usually available towards the end of 2014.

Comments welcome.

Wednesday, 15 October 2014

Surprising behaviour of metallic nanoparticles, "They wobble jelly like!"

The following report was brought to my  notice  by The Institute of Physics,UK (IOP) outreach team "Physics in Society"at the IOP. ( Phys.org Newsletter, Oct. 12, 2014).  A short summary follows:

A surprising phenomenon has been found in metal nanoparticles: They appear, from the outside, to be liquid droplets, wobbling and readily changing shape, while their interiors retain a perfectly stable crystal configuration. 

The results, published in the journal Nature Materials, come from a combination of laboratory analysis and computer modeling, by an international team that included researchers in China, Japan, and Pittsburgh, as well as at MIT.

                                          Credit: Yan Liang

More info & images may be found in NATURE MATERIALS | LETTER "Liquid-like pseudoelasticity of sub-10-nm crystalline ​silver particles" ,

  • Jun Sun,
  • Longbing He,
  • Yu-Chieh Lo,
  • Tao Xu,
  • Hengchang Bi,
  • Litao Sun,
  • Ze Zhang,
  • Scott X. Mao
  • Ju Li
  • Received 
    Accepted 
    Published online
    12 October 2014.

    The experiments were conducted at room temperature, with particles of pure silver less than 10 nanometers across—less than one-thousandth of the width of a human hair. But the results should apply to many different metals, says Li, senior author of the paper and the BEA Professor of Nuclear Science and Engineering.
    Silver has a relatively high melting point—962 degrees Celsius, or 1763 degrees Fahrenheit—so observation of any liquidlike behavior in its nanoparticles was "quite unexpected," Li says. Hints of the new phenomenon had been seen in earlier work with tin, which has a much lower melting point, he says.

    The use of nanoparticles in applications ranging from electronics to pharmaceuticals is a lively area of research; generally, Li says, these researchers "want to form shapes, and they want these shapes to be stable, in many cases over a period of years." So the discovery of these deformations reveals a potentially serious barrier to many such applications: For example, if gold or silver nanoligaments are used in electronic circuits, these deformations could quickly cause electrical connections to fail.

    The researchers' detailed imaging with a  and atomistic modeling revealed that while the exterior of the  appears to move like a liquid, only the outermost layers—one or two atoms thick—actually move at any given time. As these outer layers of atoms move across the surface and redeposit elsewhere, they give the impression of much greater movement—but inside each particle, the atoms stay perfectly lined up, like bricks in a wall.

    "The interior is crystalline, so the only mobile atoms are the first one or two monolayers," Li says. "Everywhere except the first two layers is crystalline."
    By contrast, if the droplets were to melt to a liquid state, the orderliness of the crystal structure would be eliminated entirely
    Technically, the particles' deformation is pseudoelastic, meaning that the material returns to its original shape after the stresses are removed—like a squeezed rubber ball—as opposed to plasticity, as in a deformable lump of clay that retains a new shape.
    The phenomenon of plasticity by interfacial diffusion was first proposed by Robert L. Coble, a professor of ceramic engineering at MIT, and is known as "Coble creep." "What we saw is aptly called Coble pseudoelasticity," Li says.
    Now that the phenomenon has been understood, researchers working on nanocircuits or other nanodevices can quite easily compensate for it, Li says. If the nanoparticles are protected by even a vanishingly thin layer of oxide, the liquid-like behaviour is almost completely eliminated, making stable circuits possible.

    REFS:
    Unexpected finding shows nanoparticles keep their internal crystal structure while flexing like droplets




    Friday, 26 September 2014

    Perhaps one of the most important discoveries in cement science this century.



    Perhaps one of the most important discoveries in cement science this century, say researchers at Rice Univ Texas

    “Green” concrete can lower concrete's CO2 atmospheric contribution

    MORE?
    1. “Green” concrete can lower concrete's CO2 atmospheric contribution

    2. NATURE COMMUNICATIONS  : Combinatorial molecular optimization of cement hydrates (pdf)  Published 24 Sep 2014.

    Monday, 1 September 2014

    GE pins images to fire the imagination of metallurgists and materials scientists-jobs in innovations

    Our version of "spring break" includes pushing super materials to the limit so we can learn how to m... - http://pinterest.com/pin/423338433696990354/?utm_source=android_share

    The Basic law underpinning The Development of Advanced Materials and their Manufacturing Processes

    When you're dealing with jet engines, increased efficiency means turning up the heat. - This fundamental law provides lots of challenges to the metallurgical and materials science commuities. Indeed working in these areas provided some of my greatest challenges particularily in superalloy process research and industrial development and solving these gave me immense satisfaction.



    cf. Pinterest.com

    REF: Optimizing deoxidation and desuIphurization during vacuum induction melting of alloy 718,
    J. Alexander, Materials Science and Technology, Volume: 1 Issue: 2Feb 1985, pp. 167 - 170.
    (This paper is now available via internet,via Maney Press and freely available to members of IOM3, The Institute of Materials Minerals and Mining)

    Other work : Technique to select recycled superalloy materials, involving removing rejection rate by good raw materials practice (and practised) to the satisfaction of steelworks management. "Trace Elements in Superalloys" J. Alexander, Proc The Metals Society,London1983.

    MAJOR CITATIONS:

    1988_THE MAGNESIUM PROBLEM IN SUPERALLOYS , (pdf)(cf. ref4.)
    A. Mitchell, M. Hilbom, E. Samuelsson and A. Kanagawa 
    Dept. of Metals & Materials Engineering,UBC,Vancouver, B.C., Canada, V6T lW5
    Superalloys 1988, Edited by S. Reichman, D.N. Duhl, G. Maurer, S. Antolovich and C. Lund 

    The Metallurgical Society, 1988 


    1994_PROGRESS IN  UNDERSTANDING    CLEAN METAL   PRODUCTION   FOR IN718, 
    "Desulphurisation   has been brought  to a fine  art by steelmakers, who  now 
    routinely  produce very  large heats of low-cost  steels with  sulphur  contents at a few ppm"
    A.   Mitchell, Dept. of  Metals and Materials Engineering UBC Vancouver BC Canada V6T 124 
    Superalloys  718,625,706  andvarious    Derivatives Ed.  by  E.A. Loria 
    The Minerals,  Metals  &Materials    Society,  1994    



    High Purity Cr sources for Superalloys

    Energy for th Future:Phil.Trans.A-Vol. 365, N° 1853 / April 15, 2007, curtesy The Royal Soc. London

    Engineered foams and porous materials: Phil Trans A. Vol 364, N° 1838 / 06 curtesy_The R Soc. Lond