Oxidation Behavior of Ultra-High Temperature Ceramics Using Different High-Temperature Test Facilities

Start Date

2-3-2011 10:40 AM

Description

The development of advanced thermal protection system (TPS) materials for use in next generation aerospace vehicles is needed. Ultra-high temperature ceramics (UHTCs) are considered viable candidates for hypersonic vehicle TPS materials due to their high melting temperature and good thermal conductivity. However, the need for new TPS materials has also prompted the need for the development of relevant test methods that simulate flight environments. Therefore, the focus of this talk will be to investigate the effect of high temperature test facility environments on the oxidation behavior of UHTCs. Three testing methods will be used to assess UHTCs at high temperatures (up to 2000 °C) and heat flux up to 200 Wcm-2. The first is an oxyacetylene torch set up according to ASTM E285-80 with oxidizing flame control and maximum achievable temperatures in excess of 2000 °C. The other two are high temperature static oxidation furnaces such as a thermal gravimetric analyzer and a box furnace capable of operating up to 1650 °C. The former is capable of in situ detection of weight loss and weight gain due to oxidation of the material under controlled high temperature gas mixtures thus allowing us to measure oxidation rates. In this study, ZrB2-SiC composites were processed using spark plasma sintering and were evaluated for oxidation behavior using our high temperature test facilities. The test facilities will be discussed in detail and correlated with preliminary materials evaluation results. We will also discuss collaborative testing efforts (plasma, solar furnace, and hyperthermal oxygen atoms) and on going development work at UA (dissociated air mixtures) in order to further develop an understanding for the effect of test environment on oxidation behavior of UHTCs.

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Mar 2nd, 10:40 AM

Oxidation Behavior of Ultra-High Temperature Ceramics Using Different High-Temperature Test Facilities

The development of advanced thermal protection system (TPS) materials for use in next generation aerospace vehicles is needed. Ultra-high temperature ceramics (UHTCs) are considered viable candidates for hypersonic vehicle TPS materials due to their high melting temperature and good thermal conductivity. However, the need for new TPS materials has also prompted the need for the development of relevant test methods that simulate flight environments. Therefore, the focus of this talk will be to investigate the effect of high temperature test facility environments on the oxidation behavior of UHTCs. Three testing methods will be used to assess UHTCs at high temperatures (up to 2000 °C) and heat flux up to 200 Wcm-2. The first is an oxyacetylene torch set up according to ASTM E285-80 with oxidizing flame control and maximum achievable temperatures in excess of 2000 °C. The other two are high temperature static oxidation furnaces such as a thermal gravimetric analyzer and a box furnace capable of operating up to 1650 °C. The former is capable of in situ detection of weight loss and weight gain due to oxidation of the material under controlled high temperature gas mixtures thus allowing us to measure oxidation rates. In this study, ZrB2-SiC composites were processed using spark plasma sintering and were evaluated for oxidation behavior using our high temperature test facilities. The test facilities will be discussed in detail and correlated with preliminary materials evaluation results. We will also discuss collaborative testing efforts (plasma, solar furnace, and hyperthermal oxygen atoms) and on going development work at UA (dissociated air mixtures) in order to further develop an understanding for the effect of test environment on oxidation behavior of UHTCs.