JME_V3_N3_RP4 Manab Mallik K.K. Roy Rahul Mitra Animesh Talapatra Journal on Mechanical Engineering 2249 - 0744 3 3 23 30 Ultra High Temperature Ceramic Composite (UHTCC), Micro-Structural Characterization, Mechanical Properties, Pulse-Echo ultrasonic Testing, Thermo Mechanical Properties The objective of the work is to find out microstructure and properties of two zirconium diboride based ceramic composites which were obtained from ?ne commercial zirconium diboride powders and the addition of zirconium carbide, Silicon carbide, Silicon nitride as secondary phases and correlation between microstructure-thermo mechanical properties of two Ultra High Temperature Ceramic Composites (UHTCC) based upon the different secondary phases composition. After that characterization, the influence of composition in microstructure on elevated temperature behavior of zirconium diboride based ultra high temperature ceramic composites are analysed. Micro - structural analyses by Optical and SEM showed oxidation-induced surface modifications of ZrB /SiC materials with oxide 2 layers composed of silica, boron and zirconia (at higher temperature). These composites were prepared from zirconium diboride, zirconium carbide, Silicon carbide and Silicon nitride powders by ball milling and hot pressing. These two UHTCCs were fabricated by hot pressing into 25 mm diameter and 4 mm thickness discs. The measurement of the mechanical properties of two ceramic composite were done by pulse-echo ultrasonic testing. Indentation water quenched method was used for measuring thermal stresses in UHTCCs during characterizing thermo mechanical properties and thermal shock behavior. May - July 2013 Copyright © 2013 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=2368