The variations of the crystal structure and the microstructure of reaction products formed at the interface between the Ti-contained filler metal and $Al_2O_3$ with heat-treatment in a temperature range of 850 to 1100℃ for 1 to 10 min. were studied by means of glancing angle x-ray diffraction, Auger electron spectroscopy(AES), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and transmission electron microscopy(TEM).
Ⅰ. In the $Al_2O_3$/$(Ag-Cu)_{eu}t$.-xTi(wt/o)(x=1.0 and 1.5) system, the variation of reaction layers mainly depended on heat-treatment temperature and Ti-concentration not time. When the joint was heat-treated at lower 950℃, two types of titanium oxides - δ-TiO and α-TiO in 1.5wt%Ti, and $Ti_2O$ in 1.0wt%Ti, was observed. As the δ-TiO and the $Ti_2O$ were not detected at higher 1000℃, it seemed to be transient phases. When the joint was heat-treated at higher 950℃, two types of reaction layers formed in the interface between the filler metal and the $Al_2O_3$. One was TiO and formed as small particles right beyond the $Al_2O_3$ surface. Another is one formed on the TiO layers, and was attributed to $Ti_3Cu_3O$ by x-ray, EDX and TEM analysis. The crystal structure and the lattice parameter of the second reaction layer ($Ti_3Cu_3O$) were diamond cubic and 1.128nm, respectively. The higher the heat-treatment temperature was, the faster the $Ti_3Cu_3O$ grew.
Ⅱ. In the $Al_2O_3$/Ag-yCu-2Ti(wt/o)(y=49 and 59) system, the behavior of the first reaction layer(TiO) with heat-treatment temperature represented the same as $Al_2O_3$/$(Ag-Cu)_{eu}t$.-1.5Ti system, but growth of the second reaction layer($Ti_3Cu_3O$) was accelerated at lower temperature(950℃) in relatively higher Cu-concentration (59wt%Cu).
Ⅲ. The source of oxygen for formation of reaction products was the $Al_2O_3$ by the results of XPS(x-ray photoelectron spectroscopy) analysis.
