Journal of Student Research 2014

Journal of Student Research

micro-hardness in multilayer joints was broadly consistent with the stacking sequence of metal interlayers; however, diffusion layers and reaction products that formed during joint formation at elevated temperatures yielded hardness values that could not be matched with the expected hardness because such layers and interfacial compounds were not identified in the present study. Acknowledgements: Appreciation is expressed to Ceramics Branch, NASA Glenn Research Center, Cleveland, where vacuum brazing and energy dispersive spectroscopy were conducted by Dr. Rajiv Asthana. Thanks and gratitude must also be expressed to Dr. Rajiv Asthana for mentoring and guidance throughout this research. References Asthana R and Singh M (2009), ‘Joining of ZrB2-based Ultra- high Temperature Ceramic Composites Using Pd-based Braze Alloys’, Scr. Mater., 61(3), 257-260 Bellosi, A. and Babini, G.N., Development and properties of ultra-high temperature ceramics – opportunities and barriers to application, in Freiman S (ed.) Global Roadmap for Ceramics and Glass Technology, Wiley, 2007, 847-864. Blugan, G., Janczak-Rusch, J., & Kuebler, J. (2004). Properties and fractography of Si3N4/TiN ceramic joined to steel with active single layer and double layer braze filler alloys. Acta Materialia , 52, 4579-4588. Brochu, M., Pugh, M.D., & Drew, R.A.L. (2004). Joining silicon nitride ceramic using a composite powder as active brazing alloy. Materials Science & Engineering , A374, 34-42. Gasch, M.J., Ellerby, D.T., Johnson, S.M., Ultra-high temperature ceramic composites, in Bansal N P (ed.), Handbook of Ceramic Composites , Kluwer Acad. Publishers, New York, 2005, 197-224 Hadian, A.M. & Drew, R.A.L. (1996). Strength and microstructure of silicon nitride ceramics brazed with Ni-Cr-Si alloys. Journal of the American Ceramic Society , 79(3), 659-665. Liu, G., Zou, G., Wu, A., & Zhang, D. (2006). Improvement of the Si3N4 brazed joints with intermetallics. Materials Science & Engineering , A415, 213-218. Monteverde F, Bellosi A, Guicciardi S (2002), ‘Processing and properties of ZrB2 based composites’, J. Euro Ceram. Soc.,

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