J. Mater. Sci. Technol. ›› 2021, Vol. 70: 39-48.DOI: 10.1016/j.jmst.2020.08.040

• Research Article • Previous Articles     Next Articles

Mechanisms of yttrium on the wettability, surface tension and interactions between Ni-20Co-20Cr-10Al-ξY alloys and MgO ceramics

Jinpeng Lia, Huarui Zhanga,*(), Ming Gaoa, Qingling Lia, Weidong Biana, Yongshuang Cuib, Tongxiang Taoc, Hu Zhanga   

  1. aSchool of Materials Science and Engineering, Beihang University, Beijing, 100191, China
    bChina Aerospace Academy of Systems Science and Engineering, Beijing, 100048, China
    cQingdao Institute of New Material Technology of Beihang University, Qingdao, 266000, China
  • Received:2018-12-12 Revised:2019-03-03 Accepted:2019-04-08 Published:2021-04-20 Online:2021-04-30
  • Contact: Huarui Zhang
  • About author:*.E-mail address: huarui@buaa.edu.cn (H. Zhang).

Abstract:

The mechanisms of Y on the wettability, surface tension, and interactions between the Ni-20Co-20Cr-10Al-ξY alloys and MgO ceramics at 1873 K were investigated by sessile drop experiments. The results of nonlinear fitting showed that the equilibrium contact angles and Y concentrations were approximately in accord with the log-normal distribution law. The equilibrium contact angles changed from 101.5° to 140.5° with Y increasing from 0 wt.% to 1.23 wt.%. Cross-sectional microstructure observations revealed that the thermal dissociation of ceramics occurred and the released [O] atoms can react with Y to produce Y2O3reaction layer along three-phase interphase area. Wetting kinetics analyses indicated that surface tension of the melt droplets had been positively correlated with the Y concentrations, and it increased from 737.8-1045.1 mN/m. Meanwhile, the pinning effect of the rough substrate surface on the three-phase line hindered the spreading of the liquid on ceramics. The change in total free energy of the alloys/ceramics system was considered as the key factor affecting the wettability. Moreover, the surface morphology and thermodynamic stability of ceramics also had some influence on the wettability.

Key words: Yttrium, Wettability, Interfacial interaction, Surface tension, Three-phase line