Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Research: Electric Fields Make Ceramic Production Quicker, Cheaper

By applying a 60 Hertz alternating current (AC) field, researchers were able to reduce the grain size of ceramics by 63 percent - and eliminated porosity at 1,250 degrees Celsius, as opposed to the 1,500 degrees Celsius needed without the electric field.
By applying a 60 Hertz alternating current (AC) field, researchers were able to reduce the grain size of ceramics by 63 percent - and eliminated porosity at 1,250 degrees Celsius, as opposed to the 1,500 degrees Celsius needed without the electric field.

Abstract:
Researchers from North Carolina State University have found that applying a small electric field results in faster formation of ceramic products during manufacture at lower temperatures, and enhances the strength of the ceramic itself.

By Matt Shipman

Research: Electric Fields Make Ceramic Production Quicker, Cheaper

Raleigh, NC | Posted on June 2nd, 2010

At issue is a process called sintering, which is how most ceramic products are made. The process involves taking fine ceramic powder, compressing it into the desired shape of the final product, and heating it. Under high heat, the atoms of the powder material bond by diffusion - meaning the atoms of different powder grains move around, bonding the fine powder particles together. Sintering eliminates porosity in the ceramic product, which significantly strengthens the material.

"By applying a 60 Hertz alternating current (AC) field, we were able to eliminate porosity at 1,250 degrees Celsius - as opposed to the 1,500 degrees Celsius needed without the electric field," says Dr. Hans Conrad, emeritus professor of materials science and engineering at NC State and co-author of the study. In addition, the researchers were able to reduce the grain size of the ceramic by 63 percent - creating grains with a diameter of 134 nanometers (nm), as opposed to the 360 nm diameter grains produced using conventional sintering methods. Smaller grain size makes a ceramic stronger, because the larger a grain is, the easier it is for cracks to both form and spread.

Ceramics make up significant components of an array of products, including insulators, spark plugs, fuel cells, body armor, gas turbines, nuclear rods, high temperature ball bearings, high temperature structural materials and heat shields.

The researchers were able to achieve similar, but less significant, results using an electric field created by direct current (DC). Porosity was eliminated at 1,400 degrees Celsius using DC, and grain size was reduced to a diameter of 217 nm - both still dramatic improvements over current sintering techniques. The field used for both AC and DC fields was 13.9 volts/cm.

"We found that the use of a small electric field - with a current of only six-tenths to eight-tenths of an amp per centimeter squared - can result in improved sintering rates with much finer grain size," Conrad says. In other words, ceramics manufacturers can make their products more quickly and cheaply by using an inexpensive electric field - and make their product stronger as well.

"You don't use much energy, and you put it right at the atomic site where it is needed - rather than using more energy to create higher temperatures in a kiln, which is less efficient," Conrad says. "If you want to make a strong ceramic, you want to eliminate porosity and keep the grain size as small as possible. And you want to do it at the lowest cost - which means using the smallest amount of energy and doing it at the lowest temperature at the fastest rate possible. Using an electric field achieves all of these goals."

The research is described in "Enhanced sintering rate of zirconia (3Y-TZP) by application of a small AC electric field," which will be published in a forthcoming issue of Scripta Materialia. The lead author of the paper is Dr. Di Yang, a senior research associate at NC State. This research stemmed from previous work by Yang and Conrad that was funded by the U.S. Army Research Office.

Conrad and Yang are currently working to determine the effects of the frequency and strength of the electric field and to investigate other ceramic materials.

The Department of Materials Science and Engineering is part of NC State's College of Engineering.

The study abstract follows

"Enhanced sintering rate of zirconia (3Y-TZP) by application of a small AC electrical field"

Authors: Di Yang, Hans Conrad North Carolina State University

Published: forthcoming, 2010, Scripta Materialia

Abstract: A small initial electric field E0= 13.9V/cm enhanced the sintering rate of zirconia(3Y-TZP) powder, with a 60Hz AC field having a greater effect than a DC field. The enhancement with both fields was in accord with the retardation of grain growth observed directly with SEM and with that which occurred during grain growth and plastic deformation. Some factors which could contribute to the observed behavior are given.

####

For more information, please click here

Contacts:
Matt Shipman
News Services
919.515.6386

Dr. Hans Conrad
919.515.7443

Copyright © North Carolina State 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

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Stressed Out: Research Sheds New Light on Why Rechargeable Batteries Fail October 1st, 2014

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Graphene chips are close to significant commercialization October 1st, 2014

Govt.-Legislation/Regulation/Funding/Policy

Platinum meets its match in quantum dots from coal: Rice University's cheap hybrid outperforms rare metal as fuel-cell catalyst October 1st, 2014

$18-million NSF investment aims to take flat materials to new heights: 2-D alternatives to graphene may enable exciting advances in electronics, photonics, sensors and other applications October 1st, 2014

Novel approach to magnetic measurements atom-by-atom October 1st, 2014

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Possible Futures

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Academic/Education

Yale University and Leica Microsystems Partner to Establish Microscopy Center of Excellence: Yale Welcomes Scientists to Participate in Core Facility Opening and Super- Resolution Workshops October 20 Through 31, 2014 September 30th, 2014

Rice launches Center for Quantum Materials: RCQM will immerse global visitors in cross-disciplinary research September 30th, 2014

Biosensors Get a Boost from Graphene Partnership: $5 Million Investment Supports Dozens of Jobs and Development of 300mm Fabrication Process and Wafer Transfer Facility September 18th, 2014

Malvern technology delivers Malvern reliability in multi-disciplinary lab at Queen Mary University London September 9th, 2014

Materials/Metamaterials

Rice launches Center for Quantum Materials: RCQM will immerse global visitors in cross-disciplinary research September 30th, 2014

How things coil: Researchers discover that simulation technology designed for Hollywood can be used as a predictive tool for understanding fundamental engineering problems September 29th, 2014

Iranian Scientists Determine Grain Size, Minimize Time of Nanocomposite Synthesis September 29th, 2014

Nanoparticles Used to Improve Quality of Bone Cement September 29th, 2014

Announcements

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Stressed Out: Research Sheds New Light on Why Rechargeable Batteries Fail October 1st, 2014

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Graphene chips are close to significant commercialization October 1st, 2014

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 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE