Dynamic study in partial transient liquid phase bonding of Si₃N₄/Ti/Cu/Ti/Si₃N₄

Partial transient liquid phase bonding (PTLP bonding) of Si₃N₄ ceramic with Ti (5 μm)/Cu (70μm)/Ti multi-interlayer is performed by changing time and temperature. The joint interfaces are analyzed by SEM and EDX and the kinetics in PTLP bonding of Si₃N₄ ceramic has been systematiclly studied. The results show that the growth of reaction layer and the transposition of isothemal solidification interface obey the parabolic law and are controlled by the diffusion of participating elements. It is pointed out that the optimization of the bonding parameters for the PTLP bonding of ceramics differs from that of conventional reactive brazing and the diffusion bonding. Both processes of the growth and the liquid phase isothermal solidification should be harmonized, in order to increase joint strength at room temperature and at high temperature simultaneously.