Copper diffusion during copper cordierite cosintering

The migration of copper into cordierite during a cosintering thermochemical treatment was studied mainly by energy-dispersive X-ray spectroscopy. Various samples were studied, using pressed pellets or green tapes on which copper was applied by either screen printing or sputtering. The influence of various parameters (mainly the atmosphere and the structural state of the ceramic) is presented. It is concluded that the presence of copper in the ceramic near the interface results from two processes: a mechanical transport of copper oxide particles at low temperature and a diffusion in the amorphous phase of the ceramic at high temperature.