A modified preparation technique and characterization of directionally solidified Al₂O₃/Y₃Al₅O₁₂ eutectic in situ composites

Generally, the electron beam floating zone melting (EBFZM) technique can only be used for preparing conductive materials but is not available for nonconductive ones. In this paper, a modified EBFZM technique has been developed to prepare directionally solidified Al₂O₃/Y₃Al₅O₁₂ eutectic in situ composites (nonconductive materials). The eutectic obtained shows ultra-fine interphase spacing with complex network structure and the irregular growth mechanism is investigated. Additionally, two new microstructures with regular growth morphology are observed and their formations are discussed.