Joining of Alumina to Copper Using Amorphous Cu-Ti Filler Metal(Materials, Metallurgy & Weldability)
Search this Article
Joining of alumina (99.62mass% Al_2O_3) to copper was made using amorphous Cu-Ti (34-57at%) brazing filler metals at 1173 to 1323K in 2.7×10^<-3>Pa. The amorphous filler metals, 1cm in width and 45μm thick, were produced by liquid quenching. The superior flexibility of amorphous filler provides simplicity to joining process. The fracture shear strength of the joints was measured at room temperature. The strength of the joints brazed at 1323K for 1.8ks using Cu_<50>Ti_<50> filler possesses 138.27MPa at room temperature. The strength of the joints at constant brazing time raises with an increase in brazing temperature. The strength increases slightly with an increase in titanium content in the filler. At 1298K for 1.8ks, the strength of joints at room temperature changes from 107.8MPa with Cu_<66>Ti_<34> to 120.6MPa with Cu_<43>Ti_<57>. The strength of the joints was also investigated at high temperatures up to 973K. The high temperature shear strength is almost constant up to 773K, and decreases gradually at higher temperature. Isothermal solidification process takes place during joining, and copper dissoves into Cu-Ti filler metal, and then, copper solid solution containing Ti precipitates from Cu-Ti filler metal. On the other hand, the formation of titanium oxide TiO_x and (Al, Ti)_2O_3 solid solution oxide is attributable to the strong joining between alumina and Cu-Ti filler.
- Transactions of JWRI
Transactions of JWRI 15(2), 253-258, 1986-12