AN INFLUENCE OF PHASE DEVELOPMENT ON MECHANICAL STRENGTH OF ALUMINA-COPPER JOINT PREPARED BY MOLYMn METHOD

The effect of phase development on peel strength of alumina-copper metalized joint has been investigated. The alumina-copper joint was prepared in three stages. The alumina substrate was, first, metalized at 1500°C in H2-furnace by a new formulation. In the second step, a nickel layer was electroplated on the metalized layer with approximately 10?m thickness. Finally, copper strips were bonded to metalized alumina with Ag-Cu (72-28) filler metal. The peel strength of the joint was 9.5±0.5 Kg/cm which shows approximately 30% increase in comparison to previous works. By study of fracture surface and crack propagation path, it has been concluded that this increase is due to the formation of more spinel phase.