Can orientations of directionally solidified dual-phase Al2O3 /YAG eutectics be induced by single-phase sapphire seeds?

作者：He, Liangting; Wang, Xu^*; Li, Jiaze; Xiang, Wangshuai; Yan, Fuxue; Jiang, Bailing; Hu, Qiaodan^*

来源：JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 2023, 142: 216-224.

DOI：10.1016/j.jmst.2022.08.050

• Al 2 O 3
• Y 3 Al 5 O 12
• Directional solidification
• Single-phase sapphire seed
• Crystallographic orientation relationship
• Interfacial strain energy

Directionally solidified dual-phase Al2O3/Y3Al5O12 (YAG) eutectic ceramics (DSECs) typically exhibit strong anisotropy. To improve their properties, various single-phase sapphire seeds, including r-axis [1-102], m-axis [10-10], c-axis [0 0 01], and a-axis [11-20], were used as seeds to induce the orientation of the Al2O3/YAG DSECs. The results showed that Al2O3 in the eutectics could be governed by the sapphire seeds. The YAG in each induced eutectic had a specific growth direction endowed by Al2O3 in the as-induced eutectics or the sapphire seed. Herein, we calculated the planar lattice misfits and interfacial strain energies of four crystallographic orientation relationships based on the constructed lattice models. It was elucidated the constraint of the sapphire seed caused YAG to grow following the rule of mini-mizing the interfacial strain energy. This revealed the reason why Al2O3/YAG DSECs orientation can be successfully induced. These results may provide a novel method for the design of high-performance eu-tectic ceramic materials.

• 单位
  5; 上海交通大学