Crystallographic orientation analysis and high temperature strength of melt growth composite

Abstract

A unidirectional solidified Al 2O 3/YAG binary melt growth composite (MGC) with 40 mm in diameter and 80 mm in length has been fabricated by the Bridgman method. In order to clarify crystallographic characteristics of the MGC fabricated, we carried out the crystal orientation analysis using pole figure measurement from two directions for two MGC ingots. The solidification directions of each ingot were almost [ 1 1 2 ¯ 0 ] Al 2O 3 and [1 1 0] YAG, and [ 0 1 1 ¯ 0 ] Al 2O 3 and [1 1 0] YAG, respectively. The same set of the crystal orientations which were [0 0 0 1] Al 2O 3 and [ 1 ¯ 1 2 ] YAG existed in the plane vertical to the solidification direction in two MGC ingots. Since the result of the crystal orientation analysis from two directions was corresponding, these MGC ingots were composed of a single Al 2O 3 crystal and a single YAG crystal. The relation of the crystal orientation between the Al 2O 3 phase and the YAG phase in one ingot agreed with previous studies on directionally solidified Al 2O 3/YAG eutectic composites.