Transient liquid phase bonding of copper and ceramic Al2O3 by Al/Ni nano multilayers

Abstract Transient liquid phase (TLP) diffusion bonding has been achieved for the dissimilar joining of ceramic Al 2 O 3 and copper using Al/Ni multilayers as interlayers at low temperature. The freestanding Al/Ni nano-multilayers were deposited by direct current magnetron sputtering and their properties were studied by X-ray diffraction, differential scanning calorimetry and scanning electron microscopy (SEM). The joining experiments were carried out at 550, 650 and 750 °C for a holding time of 30 min without extra pressure under nitrogen protection. The interfacial microstructure and microstructural characterization of the diffusion welded joints were investigated by SEM, energy dispersive X-ray spectroscopy and element mapping. The effectiveness of different temperatures for the mechanical properties of the joints was evaluated by shear strength. In the present work, an AuSn solder was added to expand the surface contact of the welding. The results show that the applications of Ni/Al multilayers and the AuSn solder reduce the bonding temperature and improve the joining quality.