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Grain boundary and adjacent space-charge. Credit: Conrad and Yang

According to a paper just published in Philosophy Magazine, researchers at North Carolina State University, who have been playing around with how ceramic materials behave in the presence of DC electric fields, apparently think they may have discovered an approach that could “revolutionize” ceramics manufacturing. At a minimum, they say that using a modest electric field can affect grain boundaries, and may make the process of shaping ceramics significantly more energy efficient and inexpensive compared with traditional manufacturing methods.

The researchers, lead by Hans Conrad, emeritus professor of materials science and engineering at NC State, wanted to look at how to influence the mechanical and electrical forces at grain boundaries in crystalline materials, such as ceramics.

“We found that if we apply an electric field to a material, it interacts with the charges at the grain boundaries and makes it easier for the crystals to slide against each other along these boundaries. This makes it much easier to deform the material,” says Conrad.

According to Conrad, the material becomes superplastic, allowing the ceramic to be shaped using a relatively small amount of force.

“We’ve found that you can bring the level of force needed to deform the ceramic material down to essentially zero, if a modest field is applied,” Conrad says. “We’re talking between 25 and 200 volts per centimeter, so the electricity from a conventional wall socket would be adequate for some applications.”

Diagram of DC electric field testing rig. Credit: Conrad and Yang

Conrad and his team say their findings could transform ceramic manufacturing of products from fuel cells to spark plugs to rocket nose cones. “It will make manufacturing processes more cost-effective and decrease related pollution,” Conrad says. “And these findings also hold promise for use in the development of new ceramic body armor.” Conrad says he intends to carry out more work particularly aimed at performance–cost improvements for body armor manufacturing

Conrad and Di Yang, a senior research associate at NC State, paper is titled, “Influence of an applied DC electric field on the plastic deformation kinetics of oxide ceramics.”

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The movie The Hurt Locker won big on Oscars night last weekend. The film about explosive ordinance disposal squad in Iraq scored five awards in total: Kathryn Bigelow won Best Director, and Mark Boal scored for Best Original Screenplay. It won Best Film Editing and Best Sound Editing. And finally, the film won Best Picture category.

The ceramic protective armor worn by members of the bomb squad was a major element in the film. Made of Kevlar fabric with ceramic plates, the suit is designed to protect the soldier from the impact of a blast. “We thought of it like a suit of armor that a knight would wear in medieval times,” says Boal in a Hurt Locker press release (PDF). “They have to put on, because it’s the only thing they have, but it certainly doesn’t offer foolproof protection from the enemy.”

“It’s heavy, it’s hot, it’s hard to move in, but it put me right in the moment. Just the idea of getting into it—I wanted to dry heave whenever they said it was time to get suited up. I started sweating instantly and I knew I wasn’t going to get any hotter than I was in the first 30 seconds,” recalls Jeremy Renner, actor.

Guy Pearce, the actor who plays the squad’s first leader, remarks that, “Our suit weighed about 70 pounds and I think the ones they actually wear are about 140 pounds.”

If you haven’t seen the movie, you can see one of these suits (an EOD 9 suit) in this Navy video:

This isn’t the first time a critically acclaimed movie has featured the wonders of ceramic armor. We’ve written about Batman’s ceramic armor suit used in The Dark Knight that was manufactured by Ceradyne.

Learn more about ceramic military applications in the military here.

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Monolithic ceramics represent the dominant and best-established segment of the industry). Ceramic matrix composites and ceramic coatings will achieve the more rapid gains, primarily due to their enhanced strength and durability.

A recently released report by the Freedonia Group shows that advanced ceramics will continue to penetrate applications such as capacitors, cutting tools, orthopedic joint implants and membranes, where they are valued for their favorable performance characteristics. Demand is estimated to be lower for body armor, as the Obama administration’s goal is to significantly reduce military involvement in Iraq.

The use of advanced ceramics is highly dependent on the health of the electronic components and electrical equipment industries, which combined accounted for 43% of total demand in 2007. The U.S. electronic components industry is projected to remain sluggish, limiting further advanced ceramics demand.

The medical product market will post the most rapid gains, benefiting from the increasing utilization of ceramics in joint implants and dental procedures.

Other markets set to post above-average gains include chemicals and plastics, environmental, industrial machinery and transportation equipment.

In the environmental market, pollution control is the largest application, but interest in reducing the country’s dependence on foreign oil will also provide opportunities. Emerging applications include the use of ceramic bearings in wind turbines and ceramic materials in photovoltaic modules.

The full report can be viewed at ceramicindustry.com.

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Philip Purnell with cement. (Credit: Simon and Simon Photography)

The cement wardrobe is finally growing, and this development is waaay better than shoes. Work is under way in the U.K. at University of Leeds’ School of Civil Engineering to use cement to make bullet-proof vests. They will be made from ultra-strong cement with recycled carbon filters and will be aimed at protecting nonmilitary personnel who find themselves amid gunfire.

Bullet-proof vests are currently made from alumina, but Philip Purnell, who is leading the research team, thinks cement can become a cheaper alternative. “It should be good enough for people like security guards, reporters and aid workers who are worried about the odd pot shot being taken at them. The fact is many of the armored vests sold today are over-engineered for the threats they face,” says Purnell.

“Cement-based body armor would not only create a whole new market but it would also take some of the pressure off the demand for hi-spec alumina models so that people like soldiers, who really need this kit, can get it.”

Purnell wants a team of engineers, scientists and researchers to help with the project, Cementing the Future, which he believes will uncover other uses for the material. He hopes to find more ways of using cement and has already cited other areas such as medicine and refrigeration.

“The bullet-proof vest is a small part of a much wider project. Cement is already used in waste disposal, by dentists and by spinal surgeons,” he said.

But Purnell warned that the £100,000 ($165,600) grant from the Engineering and Physical Sciences Research Council is only enough to get the project up and running. “That investment is to build a network of scientists who are looking to find new ways of using cement,” he said.

Purnell believes the project could cut the cost of body armor by up to 90 percent. It is the hope that the cement vest may ease the shortage of enhanced combat body armor for troops.

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