Durov O. Wetting and contact interaction of zirconia materials to metal melts. Manuscript

The object is the monocrystal and polycrystal zirconia; pure metals: Sn, In, Ga, Cu, Ag, Au, Al, V, Si, Ge, Fe, Co, Ni, Pd, Pt, Rh; alloys: : Cu-Ga-(Ti, Zr, V), Cu-Ge-(Ti, Zr, V), Pb-Ti, In-Ti, Ag-Cu-O; ZrO2 - metal contact board; ZrO2 - metal brazed articles. The aim is to investigate the wetting of ZrO2 by metals and the processes on ZrO2 - metal board, to elaborate the ZrO2-ceramic brazing methods. Methods are measuring of contact angle by sessile drop method, optical and electron microscopy, X-ray phase analysis, measuring of shear and bend strength. The novelty lies in for the first time complex investigation of ZrO2 wetting by pure metals, Cu-17,5Ga and Cu-16,9Ge with Ti, Zr and V additions was performed. The influence of composition, microstructure and initial stoichiometry of ZrO2-materials on wetting by metals was studied. It was reveled that the contact to active metal lead to destoihiometrisation of ZrO2, the kinetic of this process was researched, its diffusion nature was confirmed. The conservation of ZrO2 stoichiometry at contact to noble metal was revealed, it was explained by interaction of melt and zirconium in oxide. New brazing fillers and methods were elaborated.