J. Mater. Sci. Technol. ›› 2025, Vol. 220: 245-255.DOI: 10.1016/j.jmst.2024.06.059

• Research Article • Previous Articles     Next Articles

Formation mechanism of Al-O intergranular amorphous phase toughened nanoscale ZrB2-ZrC composite coating synthesized by reactive plasma spraying

Yu-hang Cuia,b, Yong Yanga,*, Dian-long Wangb,c, Yan-wei Wanga   

  1. aHebei Key Laboratory of New Functional Materials, School of Materials Science and Engineering, State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China;
    bSchool of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China;
    cSchool of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China
  • Received:2023-12-08 Revised:2024-06-04 Accepted:2024-06-24 Published:2025-06-10 Online:2025-06-17
  • Contact: *Postal address: Xiping Road No 5340, Beichen District, Tianjin, 300401, China. E-mail address: yangyong@hebut.edu.cn (Y. Yang)

Abstract: A new nanostructured ZrB2-ZrC composite coating with ZrB2-ZrC nanoscale eutectic and ZrB2+Amorphous microstructure was synthesized in situ by plasma spraying Zr-B4C-Al composite powder. The thermal analysis, quenching experiments and microstructure characterization were investigated and the formation mechanism of the bimodal in-situ microstructure was revealed. Al contributed to the liquid phase separation of molten droplets, which is the key to forming ZrB2+Amorphous microstructure. The formation of coating followed reaction-melting-liquid separation-deposition and solidification mechanism. The nanostructured ZrB2-ZrC composite coating with Al-O intergranular amorphous phase has excellent mechanical properties. The uniform nano-grains improved the hardness and the toughness of the ZrB2-ZrC eutectic. The ZrB2+Al-O amorphous microstructure obtained high toughness and the toughening mechanism was the crack deflection and crack branching caused by intergranular Al-O amorphous phase.

Key words: Nanostructured coating, In-situ synthesis, Intergranular amorphous phase, Toughening mechanism