IDENTIFICATION OF VOID SHRINKAGE MECHANISMS

A method for identifying void shrinkage mechanism experimentally is pr esented. We treat the void shrinkage on the bonded interface during so lid state diffusion bonding of similar metals. The voids are arranged at regular intervals. The experimental results were analysed by log(T/ t(s)) vs (1/T) and log t(s) vs log P plots, where T is the absolute te mperature, P the compressive stress, t(s) is the time taken to attain the void shrinkage of a certain volume DELTAV. We obtained t(s) by mea suring a certain growth of bonded area DELTAS replaced by DELTAV. Even if DELTAS is adopted, we can identify the transition of the dominant mechanism by slopes of those plots. As a result, interface self-diffus ion, volume self-diffusion and power law creep were experimentally ide ntified as fundamental mechanisms which contribute to the void shrinka ge process during diffusion bonding of metals.