The effect of TiO2/SiO2 and SiO2/Al2O3 ratio on the wettability of the TiO2–MnO–SiO2–Al2O3 quaternary welding flux system was studied using the sessile drop method by measuring the contact angle at the liquid/solid interface. The contact angle was measured at 1773 K to determine the relationship between wettability and flux structure, which is affected by the flux composition. The surface and interfacial tensions of the TiO–MnO–SiO2–Al2O3 flux system were calculated using Boni's equation and Young's equation, respectively, based on the measured contact angle. The adhesion energy, which corresponds to the energy required to separate the flux from a substrate, was calculated using Dupre's equation. The interfacial tension between the liquid flux and Pt-10Rh decreased and the surface tension increased with higher TiO2 and Al2O3. The results of the Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses of as-quenched fluxes from 1773 K also support the structural relationship with the wettability. It was found that both O− (non-bridged oxygen) and O2 − (free oxygen) affect the interfacial tension between the flux and the substrate.
Bibliographical noteFunding Information:
This work was supported by the Students' Association of the Graduate School of Yonsei University funded by the Graduate School of Yonsei University.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry