Use of Quantitative Microscopy in the Study of the Influence of Atmospheric Composition on the Sintering of Copper

The solid-state sintering of Cu is shown to proceed by a series of topological changes, all of which occur as a result of decrease in surface area and decrease in pore volume. The driving force for these changes has been demonstrated to reside in the surface tension of the metal. As a matter of sintering practice, it is well known that the process is sensitive to the composition of the gaseous atmosphere of the sintering furnace, but the reason for this has not been identified. A quantitative microscopy study has demonstrated that the atmospheric effect is not associated with the effect of different gases on the surface tension of the metal, as might have been expected, but is related rather to the effect of the different gases on the atomic transport of Cu within the sintering mass. 8 ref.--AA