Technology Bulletin 1102

Hungarian three-in-one furnace heats materials for NASA

A three-in-one Hungarian materials furnace could lead to improved designs for turbine blades and advanced lasers for true holographic projection systems. Scientists from NASA's Marshall Space Flight Center are training on an enhanced version of the Universal Multi-Zone Crystallizator at the University of Miskolc in Hungary in preparation for its transfer to NASA/Marshall in August. The UMC uses basic furnace techniques demonstrated on furnaces built by the United States and other nations, yet it has an unprecedented degree of precision. It features three different processing techniques in one apparatus. A series of 25 heaters, each 1 cm long and controllable to 0.1C at temperatures up to 1,500C, provide precise heating and cooling. These heaters eliminate the need to move the sample through a hot zone, or to move a single large heater down the length of the specimen. Instead, this system lets the UMC operate with about half as much power as a conventional furnace. An added benefit of moving the hot zone, rather than the furnace or sample, is the elimination of vibrations that can damage crystals as the samples resolidify. The heater array allows the furnace to operate in several different methods: gradient freeze, physical vapor transport, traveling solvent zone, and float zone. "You can use this furnace to look at different processing technologies that you could apply in industry," Dale Watring of NASA says. One example is high-temperature turbine blades for advanced jet engines. If the blades can be made to withstand temperatures 5 to 10 degrees higher than they can now handle, the efficiency of jet engines would increase. Hungarian researchers, Dr. Pal Barczy and Dr. Andras Roosz of the University of Miskolc, will help rebuild the UMC to fit into the Materials Science Research Facility that NASA/Marshall is developing for the International Space Station. E-mail: [email protected].

Computer modeling comes to ceramic manufacturing

As solid modeling has made a significant impact on mechanical-design rapid prototyping, computer modeling could replace the current method of making ceramics. U.S. Department of Energy's Sandia National Laboratories, five commercial ceramic manufacturers, and Los Alamos National Laboratory joined forces to develop better products at lower production costs. And they've succeeded. Especially in their primary goal to model the forming of a ceramic part on a personal computer and use that model to determine if the design has problems. "The intent is to develop simple computer programs that a layman can use on the factory floor to figure out if a component or process has any flaws, and to correct them," says Kevin Ewsuk of Sandia National Labs. "The manufacturer could then make a die from the model and be guaranteed that it will work." At $5,000 per die, eliminating the need to redesign and retool prototypes will save time and money. Ewsuk says the national laboratories' role is to analyze ceramic powders and powder compaction (forming), and to model the compaction process. The ceramic manufacturers make the ceramics parts based on the computer models, using different powders, compacting methods, and dies. Ewsuk says the project has allowed the participating companies to learn more about why some powders are difficult to press, supplied answers to why poor pressing occurs, and provided insight into how to improve powders and the conditions for pressing. He adds that by far, the most significant contribution are the "refined, discreet, and finite computer models that can be used to predict ceramic powder compaction behavior." Ewsuk says, "We expect the innovations developed will have a potential impact on other companies in search of state-of-the-art manufacturing processes." E-mail: Kevin Ewsuk, [email protected].

The next step in atomic lasers

Researchers at the National Institute of Standards and Technology (NIST, Gaithersburg, MD) demonstrated the next step in atom lasers. NIST scientists made the laser by trapping sodium atoms in a magnetic field and cooling them to a millionth of a degree above absolute zero. At this temperature, a gaseous Bose-Einstein condensate formed. This is an exotic form of matter where all atoms are indistinguishable and behave in exactly the same way as a single entity. Researchers further cooled the atoms to about 50 billionths of a degree above absolute zero. Then they aimed two optical lasers from opposite directions at the condensate. By tuning the optical lasers to different frequencies, the scientists ejected the atoms in the direction of the lower frequency laser beam. By pulsing the lasers quickly, they produced a well collimated or very narrow beam of nearly steady sodium atoms. NIST researchers say that practical uses of the laser could be years away, but they are excited about its potential use for more precise gyroscopes or interferometers. Also, because atomic wavelengths can be much smaller than light wavelengths, atom lasers should be able to produce holographic images of objects too small to be imaged with optical lasers. Call: Steven Rolston, (310) 975-6581.