Modeling of void closure in diffusion bonding process based on dynamic conditions

The dynamic conditions for plastic deformation mechanism, surface source mechanism, interface source mechanism and creep mechanism in the diffusion bonding process are proposed. Based on these dynamic conditions, a model for void closure in the diffusion bonding process is derived. The effects of diffusion bonding parameters on the bonding mechanisms are analyzed. For the diffusion bonding process of TC4 alloy, at a low diffusion bonding temperature or pressure, or for a short time, the interface source mechanism plays a main role. But, the creep mechanism is the dominant mechanism and operates until the diffusion bonding is fulfilled. As the diffusion bonding time increases, the surface source and interface source mechanism enhance and then stop at a certain stage of diffusion bonding, while the creep mechanism enhances continuously. As the diffusion bonding temperature or pressure increases, the interface source mechanism weakens and the other mechanisms enhance. The maximum and average errors between the calculated and the experimental results in the diffusion bonding for TC4 alloy are 12.86% and 5.79%, respectively.