Microstructure and Property of ZrO₂ Joint Direct Brazed with Aluminum

Abstract

In order to realize direct brazing ZrO₂ with Al, a kind of sputtering Ni/Al double layer on Al solder surface was used. Results showed that ZrO₂ could directly brazed to Al solder with sputtering Ni/Al double layer without interface reaction. And then direct brazing was investigated with the change of brazing temperature. Microstructure and joint strength of brazing seam were analyzed. Results showed that joint strength of brazing seam increased from 68.6 MPa to 121.2 MPa with the increasement of brazing temperature from 680°C to 840°C, when the brazing temperature increased up to 920°C, the joint strength gradually increased to 122.6 MPa. With the joint strength enhancement of brazing seam, the fracture of the joint is gradually transferred from interface to the brazing seam.

Fig. 7 Schematics of removing Al₂O₃ film from Al foil (a) uncoated Al foil before Al melting (b) uncoated Al foil after Al melting (c) coated Ni/Al double layer on Al foil before Al melting (d) coated Ni/Al double layer on Al foil after Al melting.