FORMATION MECHANISM OF DIFFUSION-REACTION LAYER FOR A Cu/Ti DIFFUSION COUPLE UNDER DIFFERENT HEATING METHODS

摘要

Diffusion experiments with a Cu/Ti diffusion couple were conducted using the pulse-current-heating method and the conventional-heating method. The interfacial microstructure and the growth behavior of the diffusion-reaction layer were investigated with a scanning electron microscope (SEM), electron probe micro-analyzer (EPMA), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results showed that the pulse-current heating could accelerate the diffusion of Ti atoms into a Cu matrix, significantly improve the growth rate of the diffusion-action layer, located at the side of the Cu matrix and make the growth of the interfacial reaction layer follow the parabolic rule. Meanwhile, under the pulse-current heating, the stratification of the diffusion-reaction layer was not obvious. Correspondingly, under the conventional heating method, the stratification of the diffusion-reaction layer was obvious and each reaction layer had a single microstructure, which was consistent with the reactant from the corresponding Cu-Ti binary-alloy phase diagram.