Wettability and bonding strength between copper base alloys and sintered Al2O3 compacts

Studies on the wettability and bonding of Cu-Sn-Ti (pure metals except for Ti, binary alloys and a ternary alloy) against sintered Al2O3 compacts were carried out. Wettability of Cu, Sn pure metals, Cu-10%Sn and Cu-5%Ti binary alloys in vacuum (1.3×10-2, 4.0×10-3 Pa) were unsatisfactory. Cu-10%Sn-5%Ti was comparatively wettable, where a reaction layer corresponding to Ti3Al containing slight Cu and Sn was formed in the interface between the brazing alloy and sintered Al2O3 compact. Sn-5%Ti binary alloy against sintered Al2O3 showed fair wettability, but did not form any reaction layer. Bonding strength of sintered Al2O3 compacts brazed with Cu, Sn pure metals and Cu-10%Sn or Cu-5%Ti had a tendency to decrease with increasing the degree of vacuum (or with decreasing oxygen partial pressure) of the bonding atmosphere. Bonding strength of sintered Al2O3 compacts brazed with Sn-5%Ti and Cu-10%Sn-5%Ti alloys were comparatively high and had a tendency to increase with a higher bonding temperature.