EBSD Analysis for Orientation Relationship of Textured ZrB2-SiC Ultra-high Temperature Ceramics

Textured ZrB 2 -ZrC ceramics sintered by spark plasma sintering were analyzed.The results obtained by SEM and EDS demonstrate the formation of an amount of resultant ZrC phase and trace level of ZrO 2 and BN phases, due to the various reactions between starting powders and impurities.Compared with conventional methods in which TEM was used to analyze the orientation relationship between the phase and the primary phase, EBSD method in SEM can not only study the orientation relationship, but also study a large number of phase boundaries simultaneously to obtain statistical results, so as to avoid artificial selectivity.By using this method, three orientation relationships that may exist between ZrB 2 and ZrC phases, i.e. (011 ¯0)||(111)&[21 ¯1 ¯0]||[101 ¯], (112 ¯0)||(2 ¯02)&[0001]||[111], and (1 ¯21 ¯0)|| (2 2 ¯0)&[0001]|| [110] were checked.It is determined that there is no specific orientation relationship between the two phases in this study, inferring that the ZrC phase formed with a homogeneous nucleation mode rather than an epitaxial nucleation.