Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Space Industry and Business News .




TECH SPACE
Study reveals clues to cause of hydrogen embrittlement in metals
by Staff Writers
Montreal, Canada (SPX) Nov 22, 2012


State-of-the-art computer simulations were performed by Song to reveal explicitly how hydrogen atoms move within metals and how they interact with metal atoms.

Hydrogen, the lightest element, can easily dissolve and migrate within metals to make these otherwise ductile materials brittle and substantially more prone to failures. Since the phenomenon was discovered in 1875, hydrogen embrittlement has been a persistent problem for the design of structural materials in various industries, from battleships to aircraft and nuclear reactors.

Despite decades of research, experts have yet to fully understand the physics underlying the problem or to develop a rigorous model for predicting when, where and how hydrogen embrittlement will occur. As a result, industrial designers must still resort to a trial- and-error approach.

Now, Jun Song, an Assistant Professor in Materials Engineering at McGill University, and Prof. William Curtin, Director of the Institute of Mechanical Engineering at Ecole Polytechnique Federale de Lausanne in Switzerland, have shown that the answer to hydrogen embrittlement may be rooted in how hydrogen modifies material behaviours at the nanoscale.

In their study, published in Nature Materials, Song and Curtin present a new model that can accurately predict the occurrence of hydrogen embrittlement.

Under normal conditions, metals can undergo substantial plastic deformation when subjected to forces. This plasticity stems from the ability of nano- and micro-sized cracks to generate "dislocations" within the metal - movements of atoms that serve to relieve stress in the material.

"Dislocations can be viewed as vehicles to carry plastic deformation, while the nano- and micro-sized cracks can be viewed as hubs to dispatch those vehicles," Song explains.

"The desirable properties of metals, such as ductility and toughness, rely on the hubs functioning well. Unfortunately those hubs also attract hydrogen atoms.

The way hydrogen atoms embrittle metals is by causing a kind of traffic jam: they crowd around the hub and block all possible routes for vehicle dispatch. This eventually leads to the material breaking down."

State-of-the-art computer simulations were performed by Song to reveal explicitly how hydrogen atoms move within metals and how they interact with metal atoms. This simulation was followed by rigorous kinetic analysis, to link the nanoscale details with macroscopic experimental conditions.

This model has been applied to predict embrittlement thresholds in a variety of ferritic iron-based steels and produced excellent agreements with experiments. The findings provide a framework for interpreting experiments and designing next-generation embrittlement-resistant structural materials.

The research was funded in part by the Natural Sciences and Engineering Research Council of Canada, the U.S. Office of Naval Research and by the General Motors/Brown Collaborative Research Lab on Computational Materials.

.


Related Links
McGill University
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
China sets special funds to boost rare earth sector
Shanghai (AFP) Nov 21, 2012
China said Wednesday it would allocate special funds to its rare earths sector to support producers hit by weak prices, but did not give the total amount. China produces more than 95 percent of the world's rare earths, 17 elements crucial for making a range of hi-tech products. The country's control over the sought-after resources - through production caps and export quotas - has spark ... read more


TECH SPACE
Thermogenerator from the Printer

University of Glasgow and Clyde Space set to put brakes on space junk problem

Study reveals clues to cause of hydrogen embrittlement in metals

Smartphones crushing point-and-shoot camera market

TECH SPACE
Lockheed Martin to Demonstrate Key Component of Tactical MilSat Communications System

The Skynet 5D secure telecom satellite is received in French Guiana for Arianespace's December Ariane 5 mission

Lockheed Martin Completes On Orbit Testing of Second AEHF Satellite

LynuxWorks LynxOS-SE Deployed by ITT Exelis in New Line of Software-Defined Radios

TECH SPACE
Pleiades 1B is ready for integration in the payload "stack" for Arianespace's next Soyuz mission

France, Germany compromise on Ariane launcher: minister

Mexsat Bicentenario is delivered to French Guiana for its December launch on Ariane 5

France, Germany seek Ariane compromise at ESA space meet

TECH SPACE
Lockheed Martin Completes Critical Environmental Test on GPS III Pathfinder

Roscosmos Requests Glonass Project Contractor Head's Dismissal

Mobile GPS Tracking capability on JCB ruggedized mobile phones

Quattro Group Gains Visibility And Control With Ctrack

TECH SPACE
Boeing Adapts Innovative Training Technologies to FA-18E and F-15E

US Navy Selects Lockheed Martin to Modernize C-130T Aircraft

Boeing and AVIC to Collaborate on Interior Supply Capability in China

F-35A Achieves Maximum High Angle Of Attack Limit In Four Flights

TECH SPACE
USC scientists 'clone' carbon nanotubes to unlock their potential for use in electronics

Intel to seek new CEO, Otellini to retire in May

First noiseless single photon amplifier

New study reveals challenge facing designers of future computer chips

TECH SPACE
What lies beneath? New survey technique offers detailed picture of our changing landscape

How many Russian Earth observation satellites will be in orbit by 2015?

A SPOT 6 Success Story

China launches third environment monitoring satellite

TECH SPACE
India's capital widens ban on plastic bags

Trash exhibition offers fresh peek at Everest

Earth on Acid: The Present and Future of Global Acidification

Technology can spot hazardous materials




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement