Yttrium-Stabilized Zirconia: A Mouthful at Mach Speed

(Image source: ceramics.org)

A paper published as an "Early View" article by the Journal of the American Society shows that yttrium-stablized zirconia can be sintered to full density in a matter of seconds at 850 degrees Celsius. The key is subjecting the process to a dc electrical field above the critical threshold. Traditional YSZ sintering would require hours at 1450 degrees Celsius. The paper was written by Marco Cologna, Rishi Raj and Boriana Rashkova, who are in the process of testing other materials that they hope to be able to report on to the ceramic manufacturing community soon. An article from ceramics.org covers the story. Here's an excerpt:

"The trio's technique was fairly straightforward. They made dog-biscuit shaped samples from 3 mol% nanograin YSZ. They then sintered samples in a vertical tubular furnace, applying a constant dc voltage, varying temperature and voltage. In the stages of their tests, they encountered a phenomenon I have written about before: accelerated sintering speeds at lower temperatures, dubbed field-assisted sintering or "FAST". In fact Raj, Di Yang and Hans Conrad had recently published another paper about how low (20 V/cm) dc electric dields could speed sintering and slow grain growth."

With many radical advances taking place in the field of ceramics engineering since the end of the century, it should come as no surprise that a leap-forward in sintering technology is nigh on the horizon. While the process has not been perfected yet, and the reports are only preliminary at this point, those in our industry would do well to look forward to a more detailed report coming from this team in the coming months.

To learn more about ceramics engineering, check out Refractron:

www.refractron.com

To read the article from ceramics.org, following this link:

http://ceramics.org/ceramictechtoday/materials-innovations/sintering-in-a-flash-researchers-show-its-possible-to-do-it-in-seconds-with-nanograin-ysz-heat-and-dc-electric-field/

In Honor of C. Jeffrey Brinker

(Image Source: The National Center for Design of Biomimetic Semiconductors)

At the Materials Science and Technology 2010 Conference & Exhibition, there will be a symposium organized to commemorate the work of C. Jeffrey Brinkley, who recently won the 2010 Robert B. Sosman award. According to the American Ceramic Society webpage, the Robert B. Sosman award is the highest recognition of scientific accomplishment given by the Basic Science Division and is given in recognition of outstanding achievement in basic science of an area that result in a significant impact on the field of ceramics. The awardee presents a plenary lecture at the ACerS Annual Meeting, and receives a certificate commemorating the event and a piece of glassware. The lecture is given each year by the awardee who has been deemed by the award committee to have made the most significant contribution to the field of ceramics.

According to the MS&T '10 website, "For his work, [Brinkley] is recognized around the world as a foremost expert in the field. He has contributed to our fundamental understanding of sol-gel processing, including kinetics of reactions, kinetics of growth and fractal structure of the solider clusters formed in solution, and the pore structure, surface chemistry, and densification behavior of the dried gel. The symposium will focus on sol-gel science and applications. The talks in this half-day symposium will be by invitation only and will feature recent investigations on the chemistry of sol-gel processing, fundamental behavior of hels, and recent materials developed by this technique."

So this week, the Ceramic Engineering Blog honors C. Jeffrey Brinkley for his advancements in sol-gel technology and his dedication to the field of ceramics engineering.

To learn more about ceramics engineering, check out Refractron:

www.refractron.com

To read the article regarding the MS&T '10 conference, click here:

http://matscitech.org/program/technical-program/ceramic-and-glass-materials/

And to visit the ACerS site to learn more about their awards and commendations, hit this link:

http://ceramics.org/acers-community/award-winners-resources/

Getting to Know your Magnets - The Design of Product Purity

(Image Source: Mark Weiss, thisoldhouse.com)

A recent special report from ceramicindustry.com discusses the importance of purity in a ceramics manufacturing process. It is likely that some contaminates, ferrous metals and others, may sometimes end up in a process where they have the potential to jeopardize the homogeny of a substance or damage machinery. As a result, the use of high-power magnetic separators must be employed to ensure the purity of your process. The article discusses the different types of magnets and metal detectors that can be employed and is a good read for anyone in the ceramics manufacturing industry. Here's an excerpt:

"Magnetic separators are classified as type A, B or C, in accordance with the type of magnetic circuit used. Processing lines are generally designated into the main areas (applications): primary, secondary and finishing. The size of the tramp metal to be removed determines whether a type A, B or C circuit is used. Type A is recommended for small fragments, while types B and C are recommended for larger tramp metals."

The article goes on to discuss the relationship between sensitivity and stability during the metal removal process, and explains precisely how these machines work. If you're in the ceramics manufacturing industry and you're not sure what the difference between these types of magnetic separators are, or are not sure how they work, the article is definitely a good read. In order to keep our products and processes free of unwanted contaminates, the use of metal detection and elimination is instrumental.

To learn more about ceramics engineering, visit Refractron:

www.refractron.com

To read the article from ceramicindustry.com, follow this link:

http://www.ceramicindustry.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000000892771

Growing Concerns Over Rare Earth Metals...

(Image Source: Missouri State University)

A recent article from the New York Times discusses the escalating problems that the United States and other nations of the world are having with maintaining a steady supply of rare earth metals. The article calls the situation a Chinese "hammerlock" that may sway the tides of import and export for several countries around the world for years to come. According to the article, 99 percent of two important elements: dysprosium and terbium come from China, who has recently put even tighter limits on the amount of these elements that can be exported, as China's own requirements for the elements has steadily increased over the last three years. The article explains it this way:

"In each of the last three years, China has reduced the amount of rare earths that can be exported. This year's export quotas are on track to be the smallest yet. But what is really starting to alarm Western governments and multinationals alike is the possibility that exports will be further restricted. Chinese officials will almost certainly be pressed to address the issue at a conference Thursday in Beijing. What they say could influence whether Australian regulators next week approve a deal by a Chinese company to acquire a majority stake in Australia's main rare-earth mine."

The article lists the commonly accepted price for the rare earth terbium at around 150$ pound on average. The reason that this information should alarm ceramics engineers is because we are in a constantly evolving industry. At some point, restrictions regarding materials will begin to affect us, whether it be restrictions with the number of chemicals we ourselves can export due to the global marketplace reaching a standstill or our inability to get a new element that it is discovered greatly benefits the ceramic industry. At one point, the idea of mixing diamonds with ceramic materials may have seemed silly, but today we have Diacer. It is likely that this international escalation will not stop with just terbium and dysprosium.

To learn more about ceramics engineering, visit Refractron:

www.refractron.com

And to read the article in the New York Times, follow this link:

http://www.nytimes.com/2009/09/01/business/global/01minerals.html

Biomaterialization and the New Vernacular...

(Image Source: www.azom.com)

Biomaterialization is a relatively new term in the scientific community, most notably used in areas regarding the production of inorganic materials based on the emulation of organic processes. The traditionally used term of 'biomineralization' is unsatisfactory, most notably because it refers to inorganic minerals being synthesized from biological micro- and nanostructures, when in reality they are inorganic materials that are derived from the mimicry of organic nanostructure processes. Recently, scientists from the University of Stuttgart have discovered a process by which they can produce oxide ceramics by biological means. A recent article from AZO materials discusses their progress:

"The scientists imitate the natural concept of biomineralization to produce non-metallic inorganic materials under environmental conditions. Organisms produce a bioorganic template to induce and control the formation of an inorganic phase (e.g. calcium carbonate) in an aqueous solution. This natural process offers promising perspectives for the synthesis of functional materials. Unfortunately, nature produces only minerals with minor technical importance. The interdisciplinary working group of Stuttgart University under participation of institutes of the faculties for chemistry as well as for energy technology, process engineering and biological engineering is working to overcome this issue."

For those in the ceramics manufacturing industry, the new terminology and the new process will be significant. As the article says, oxide ceramics such as titania, zinc oxide and zirconia are used in photovoltaic and fuel cells, and are in high demand due to their application as a scratch-resistant coating. With our industry constantly evolving, it's important for ceramics manufacturers to pay attention to new words like 'biomaterialization', as well as be aware of what they represent. This recent breakthrough serves as a shining example of how new developments may shape not only the future of materials sciences, but how we talk about ceramics engineering.

To read more about ceramics engineering, check out Refractron:

www.refractron.com

To read the article from AZO materials, follow this link:

http://www.azom.com/news.asp?NewsID=18207

And to read more about discussion related to terminology in biomimetics, click here:

http://rsta.royalsocietypublishing.org/content/367/1894/1705.full

New Stipulations From The EPA On The Horizon...

The latest article from Chemical and Engineering News discusses a new proposal by the Environmental Protection Agency, which states that chemical manufacturers may have to provide reports regarding processing, productions and purpose for using their compounds every four years instead of five. Under the Toxic Substances Control Act, chemical makers must report twice yearly to the EPA in order to keep the TSCA Inventory updated. This has been the standard ever since the presidency of George W. Bush, when the EPA changed its time frame to the now recognized five year policy (Previously it was four years also). The article states:

“The proposed rule “will allow the agency to more effectively and expeditiously identify and address potential chemical risks and improve the information available to the public on chemicals most commonly used in commerce,” says Steve Owens, EPA assistant administrator for the Office of Chemical Safety & Pollution Prevention. The agency expects to finalize the changes by mid-2011.”

In addition to these new stipulations, this proposal would also require that companies that engineer chemicals make known in advance that the data that is supplied to the EPA is confidential business information, or it could potentially be placed in the public domain. This is likely the result of the EPA administrator, Lisa P. Jackson’s recent campaign to stop unnecessary trade secret claims from some members of the chemical industry. What this means for chemical manufacturers is that it looks like it’s back to the old way of doing things, so be prepared to modify your budgets.

www.refractron.com

To read the article from Chemical and Engineering News, click here:

http://pubs.acs.org/cen/news/88/i33/8833news4.html

New Ceramics Wrap Themselves in Blankets of Air to Ward Off Cold

At The Ceramic Engineering Blog, we've decided to continue our run of cold-themed posts (what with the heat wave and all it just seemed appropriate) by taking a look at a story that fell through the cracks for us this year. Back in March, NewScientist Magazine ran an article regarding a new technology developed by the Chinese Academy of Sciences and their colleagues which allows ceramics which endure extreme temperature changes to resist fracturing when moved from a high temperature environment to a low temperature, the scientists able to get the material to maintain its strength even when cooling from near-melting point temperatures of around 3,210 degrees Celsius. The article by NewScientist explains the process:

"They did this by roughening the surface with plasma etching and concentrated nitric and hydrofluoric acids. The surface ended up covered in nanoscale fin shapes, similar to the nanoscale patterning of a lotus leaf. Like those leaves, the roughened ceramic is strongly hydrophobic, or water repellant. This is what makes the material resistant to heat shock. It traps pockets of air at its roughened surface, so when cooled suddenly by dunking in water, or if the surrounding air temperature changes, the air pockets act as an insulating layer, buffering the bulk of the ceramic from the rapid change in temperature."

This new technology could potentially lead to a change in the types of materials used for applications which require thermally resistant, high-strength materials. Processes which usually use expensive metal alloys, such as those found within car engines, could be soon replaced by for efficient and less expensive ceramic materials. This could be an exciting prospect for the ceramics manufacturing industry, and is certainly something that those of us in the industry should keep an eye on.

To read the article from NewScientist Magazine:

http://www.newscientist.com/article/dn18685-new-ceramic-is-not-afraid-of-the-cold.html

To learn more about thermally resistant ceramics materials, check out Refractron:

http://www.refractron.com/ceramic_materials.asp