Journal of Inorganic Materials ›› 2011, Vol. 26 ›› Issue (8): 841-846.doi: 10.3724/SP.J.1077.2011.00841

• Research Paper • Previous Articles     Next Articles

Microstructure and Fracture Toughness of Al2O3/Er3Al5O12 Eutectic Ceramic Prepared by Laser Zone Remelting

DENG Yang-Fang, ZHANG Jun, SU Hai-Jun, SONG Kan, LIU Lin, FU Heng-Zhi   

  1. (State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
  • Received:2010-10-03 Revised:2010-11-20 Online:2011-08-20 Published:2011-07-14
  • Contact: ZHANG Jun
  • Supported by:

    National Natural Science Foundation of China (51002122, 50772090); Natural Science Foundation of Shaanxi Province (2010JQ6005); Aeronautical Science Foundation of China (2010ZF53064); NPU Foundation for Fundamental Research (NPU-FFR-G9KY1016); New People and New Directions Foundation of School of Materials Science and Engineering in NPU (09XE0104-5); Research Fund of the State Key Laboratory of Solidification Processing in NPU (76-QP-2011)

Abstract: Directionally solidified Al2O3/Er3Al5O12(EAG) eutectic ceramic was prepared by laser zone remelting technique. The eutectic morphology and microstructure evolution investigated as a function of laser scanning rate. Moreover, the mechanical properties and toughening mechanisms were studied. The Al2O3/EAG eutectic ceramic consists of only two continuous phases of Al2O3 and EAG which interpenetrates with each other to form well-distributed three-dimensional network. The eutectic spacing is only around 0.2-2.1μm and reduces with the increase of scanning rate. At low scanning rate, the typical lamellar irregular eutectic structure is obtained. When the scanning rate reaches 800μm/s, the cellular or dendrite microstructure appears. The hardness and the fracture toughness at room temperature are measured to be 18.7GPa and 2.45MPa·m1/2, respectively. The refined microstructure, crack deflection at phase interface and crack branching contribute to the improved toughness.

Key words: oxide eutectic ceramic, laser zone remelting, microstructure, fracture toughness

CLC Number: 

  • TB332