Investigation of Flux-Less Soldering of Metal Matrix Composite and Ceramics by Use of Zn Solder

The work was dealing with direct soldering of Al₂O₃ ceramics and a metal/ceramic composite (MMC) with Al matrix. The joints were fabricated by application of flux-less process by use of a hot plate at the assistance of ultrasound with frequency of 40 kHz. The experiments were performed by use of Zn6Al6Ag solder. Wetting was attained on both substrates. The joints of a good quality were fabricated. The soldering temperature was 420 °C. The microstructural studies of interface have revealed a transient zone of Al dissolving on the side of MMC and formation of Zn oxides on the side of ceramics, which were responsible for bond formation.