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

University of Manchester selects Anasys AFM-IR for coatings and corrosion research July 30th, 2014

Nature inspires a greener way to make colorful plastics July 30th, 2014

Analytical solutions from Malvern Instruments support University of Wisconsin-Milwaukee researchers in understanding environmental effects of nanomaterials July 30th, 2014

FEI Unveils New Solutions for Faster Time-to-Analysis in Metals Research July 30th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Nature inspires a greener way to make colorful plastics July 30th, 2014

Tough foam from tiny sheets: Rice University lab uses atom-thick materials to make ultralight foam July 29th, 2014

A new way to make microstructured surfaces: Method can produce strong, lightweight materials with specific surface properties July 29th, 2014

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties July 28th, 2014

Possible Futures

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

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

Academic/Education

University of Manchester selects Anasys AFM-IR for coatings and corrosion research July 30th, 2014

Haydale Announces Collaboration Agreement with Swansea University’s Welsh Centre for Printing and Coatings (WCPC) July 12th, 2014

STFC takes delivery of the 100th Hitachi Tabletop SEM in the UK July 3rd, 2014

Innovation Management and the Emergence of the Nanobiotechnology Industry July 1st, 2014

Materials/Metamaterials

Nature inspires a greener way to make colorful plastics July 30th, 2014

Flexible Metamaterial Absorbers July 29th, 2014

Tough foam from tiny sheets: Rice University lab uses atom-thick materials to make ultralight foam July 29th, 2014

A new way to make microstructured surfaces: Method can produce strong, lightweight materials with specific surface properties July 29th, 2014

Announcements

University of Manchester selects Anasys AFM-IR for coatings and corrosion research July 30th, 2014

Nature inspires a greener way to make colorful plastics July 30th, 2014

Analytical solutions from Malvern Instruments support University of Wisconsin-Milwaukee researchers in understanding environmental effects of nanomaterials July 30th, 2014

FEI Unveils New Solutions for Faster Time-to-Analysis in Metals Research July 30th, 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