Ceramics joining using explosive metal foil

A capacitor discharge joining technique used to fabricate alumina (Al/sub 2/O/sub 3/) tile-titanium foil-Al/sub 2/O/sub 3/ tile joint was investigated with focusing to increase the bonding strength. Several kAs pulse current was supplied from 8.28 /spl mu/F storage capacitor to the 50 /spl mu/m thickness titanium foil which was sandwiched between the Al/sub 2/O/sub 3/ tiles with various pressures. The temperature of the foil was rapidly increased owing to ohmic heating with the large current, and then the foil was liquefied and vaporized. The Al/sub 2/O/sub 3/ tiles were successfully bonded when the input energy to the titanium foil was higher than the energy required for the foil vaporization. The bonding strength increases with increasing the energy input to the foil. However, the foil explosion cracked the tiles when the input energy exceeds a critical value. Increasing the circuit inductance from 1.13 /spl mu/H to 64.8 /spl mu/H, the critical energy of tile cracking increases from 160 J to 507 J. The maximum bonding strength of 3200 N was obtained when the circuit inductance was 21.8 /spl mu/H. An investigation of the interfacial structure of the joints using electron probe microanalysis revealed that distinct reaction areas existed in the interlayer.