Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Brown University Scientists Discover New Principle in Material Science

Atomic Strength: A material science team led by Brown University engineers has found that the deformation of nanotwinned metals is characterized by the motion of highly ordered, necklace-like patterns of crystal defects called dislocations. Credit: Huajian Gao and Xiaoyan Li/Brown University
Atomic Strength: A material science team led by Brown University engineers has found that the deformation of nanotwinned metals is characterized by the motion of highly ordered, necklace-like patterns of crystal defects called dislocations. Credit: Huajian Gao and Xiaoyan Li/Brown University

Abstract:
A material science team led by Brown University engineers has found that the deformation of nanotwinned metals is characterized by the motion of highly ordered, necklace-like patterns of crystal defects called dislocations.

Brown University Scientists Discover New Principle in Material Science

Providence, RI | Posted on April 8th, 2010

Materials scientists have known that a metal's strength (or weakness) is governed by dislocation interactions, a messy exchange of intersecting fault lines that move or ripple within metallic crystals. But what happens when metals are engineered at the nanoscale? Is there a way to make metals stronger and more ductile by manipulating their nanostructures?

Brown University scientists may have figured out a way. In a paper published in Nature, Huajian Gao and researchers from the University of Alabama and China report a new mechanism that governs the peak strength of nanostructured metals. By performing 3-D atomic simulations of divided grains of nanostructured metals, Gao and his team observed that dislocations organize themselves in highly ordered, necklace-like patterns throughout the material. The nucleation of this dislocation pattern is what determines the peak strength of materials, the researchers report.

The finding could open the door to producing stronger, more ductile metals, said Gao, professor of engineering at Brown. "This is a new theory governing strength in materials science," he added. "Its significance is that it reveals a new mechanism of material strength that is unique for nanostructured materials."

Divide a grain of metal using a specialized technique, and the pieces may reveal boundaries within the grain that scientists refer to as twin boundaries. These are generally flat, crystal surfaces that mirror the crystal orientations across them. The Chinese authors created nanotwinned boundaries in copper and were analyzing the space between the boundaries when they made an interesting observation: The copper got stronger as the space between the boundaries decreased from 100 nanometers, ultimately reaching a peak of strength at 15 nanometers. However, as the spacing decreased from 15 nanometers, the metal got weaker.

"This is very puzzling," Gao said.

So Gao and Brown graduate student Xiaoyan Li dug a little further. The Brown scientists reproduced their collaborators' experiment in computer simulations involving 140 million atoms. They used a supercomputer at the National Institute for Computational Sciences in Tennessee, which allowed them to analyze the twin boundaries at the atomic scale. To their surprise, they saw an entirely new phenomenon: A highly ordered dislocation pattern controlled by nucleation had taken hold and dictated the copper's strength. The pattern was characterized by groups of atoms near the dislocation core and assembled in highly ordered, necklace-like patterns.

"They're not getting in each other's way. They're very organized," Gao said.

From the experiments and the computer modeling, the researchers theorize that at the nanoscale, dislocation nucleation can become the governing principle to determining a metal's strength or weakness. The authors presented a new equation in the Nature paper to describe the principle.

"Our work provides a concrete example of a source-controlled deformation mechanism in nanostructured materials for the first time and, as such, can be expected to have a profound impact on the field of materials science," Gao said.

The other researchers who contributed to the paper are Yujie Wei from the University of Alabama and Ke Lu and Lei Lu from the Chinese Academy of Sciences. The U.S. National Science Foundation, the National Science Foundation in China and the Ministry of Science and Technology in China funded the research.

####

For more information, please click here

Contacts:
Richard Lewis
(401) 863-3766

Copyright © Brown University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Keysight Technologies Shifts to Direct Sales of High-Performance Products in North America March 3rd, 2015

Cambrios and Heraeus Jointly Create New, High-Conductivity Transparent Conductors: Two Companies' Combined Products Dramatically Extend Flexible Substrate Capabilities for Next-Generation Mass-Market Technology Products March 3rd, 2015

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Govt.-Legislation/Regulation/Funding/Policy

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

New nanodevice defeats drug resistance: Tiny particles embedded in gel can turn off drug-resistance genes, then release cancer drugs March 2nd, 2015

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

Possible Futures

European roadmap for graphene science and technology published February 25th, 2015

Quantum research past, present and future for discussion at AAAS February 16th, 2015

World’s first compact rotary 3D printer-cum-scanner unveiled at AAAS by NTU Singapore start-up: With production funded by crowdsourcing, the first unit will be delivered to the United States in March February 16th, 2015

Nanotechnology Electric Vehicle (EV) Market Analysis Report 2015: According to Radiant Insights, Inc February 13th, 2015

Academic/Education

NanoTecNexus Launches New App for Learning About Nanotechnology—STEM Education Project Spearheaded by Interns February 26th, 2015

SUNY Poly CNSE Researchers and Corporate Partners to Present Forty Papers at Globally Recognized Lithography Conference: SUNY Poly CNSE Research Group Awarded Both ‘Best Research Paper’ and ‘Best Research Poster’ at SPIE Advanced Lithography 2015 forum February 25th, 2015

KIT Increases Commitment in Asia: DAAD Funds Two New Projects: Strategic Partnerships with Chinese Universities and Communi-cation Technologies Network February 22nd, 2015

Minus K Technology Announces Its 2015 Vibration Isolator Educational Giveaway to U.S. Colleges and Universities February 18th, 2015

Discoveries

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Pens filled with high-tech inks for do-it-yourself sensors March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Materials/Metamaterials

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Breakthrough in OLED technology March 2nd, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

Announcements

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Pens filled with high-tech inks for do-it-yourself sensors March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Research partnerships

Cambrios and Heraeus Jointly Create New, High-Conductivity Transparent Conductors: Two Companies' Combined Products Dramatically Extend Flexible Substrate Capabilities for Next-Generation Mass-Market Technology Products March 3rd, 2015

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Breakthrough in OLED technology March 2nd, 2015

UC research partnership explores how to best harness solar power March 2nd, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE