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Case study: Building an ultra-high-temperature mechanical testing system The chamber is purged with argon for a typical workday. in the same department at Missouri 30 minutes, which is enough to change This system eliminates the barriers S&T. Harlan Brown-Shaklee is a the atmosphere in the chamber twice. that once prevented ultra-high-temper- former graduate student in the MSE After purging, the induction coil is ature mechanical testing and makes it Department at Missouri S&T and is energized. The typical heating rate is possible for us to study the mechanical currently a postdoctoral researcher at 100°C per minute until the tempera- behavior of UHTCs at the extreme Sandia National Laboratories. Contact: ture is about 100°C below the testing temperatures likely to be encountered G. Hilmas, ghilmas@mst.edu. temperature, and the testing tempera- during hypersonic flight. ture is approached at 50°C per minute. References A five-minute hold prior to applying Acknowledgments 1W.G. Fahrenholtz, G.E. Hilmas, I.G. the load allows for thermal equilibra- Research on ultra-high-temperature Talmy, and J.A. Zaykoski, “Refractory tion before testing. mechanical testing is supported at Diborides of Zirconium and Hafnium,” J. Standard commercial software oper- Missouri S&T by the Aerospace Am. Ceram. Soc., 90 5 1347–64 (2007). ates the test frame and controls the dis- Materials for Extreme Environments 2E.W. Neuman, G.E. Hilmas, and W.G. placement rate, as well as capturing the program of the Air Force Office of Fahrenholtz, “Strength of Zirconium resulting displacement and load. Once Scientific Research. The authors wish Diboride to 2300°C,” J. Am. Ceram. Soc., the specimen has failed, the induction to thank program manager Ali Sayir for in press. coil is de-energized, and the furnace his guidance and support. 3W.H. Rhodes, E.V. Clougherty, and D. cools. Because of the low thermal mass Kalish, “Research and Development of of the insulation, the furnace cools to About the authors Refractory Oxidation-Resistant Diborides below 600°C in about one hour. Below Eric W. Neuman is a graduate stu- Part II, Volume IV: Mechanical Properties,” 600°C, the environmental chamber can dent in the Department of Materials Technical Report AFML-TR-68-190, Part II, Volume IV, ManLabs Inc. and Avco be opened to allow the hot zone to cool Science and Engineering at Missouri Corp., Wright Patterson Air Force Base, more rapidly. Using this methodology, University of Science and Technology, Ohio, 1970. n we can test as many as four specimens Rolla, Mo. Jeremy Watts, Greg Hilmas, at temperatures of 2,000°C or above in and William G. Fahrenholtz are faculty ORDER VERSION 3.4 ACERS–NIST PHASE EQUILIBRIA DIAGRAMS FOR CERAMIC SYSTEMS Version 3.4 includes 1,400 new diagrams, bringing the grand total to approximately 25,000. New content includes experimental and calculated data for an unprecedented range of non-organic material types, including oxides and mixed systems with Download the oxides, chalcogenides, pnictides, actinides and actinide- Version 3.4 demo surrogates, oxycation systems, semiconductors, group3 systems, and mixed systems with salts. for free! www.ceramics.org/phasecd 38 www.ceramics.org | American Ceramic Society Bulletin, Vol. 92, No. 1


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