In situ investigation of Al-Ti mixed metal system microwave sintering by synchrotron radiation computed tomography

Abstract

In this paper, in-situ investigation of Al-Ti mixed system's microwave sintering was carried out on the basis of synchrotron radiation tomography technique. Quantitative parameters including porosity and sintering neck growth were extracted from experimental images. Al-Ti mixed sample had a faster densification and sintering neck growth rate by comparing with the microwave sintering of pure aluminum. The possible mechanisms which accelerated the sintering process of Al-Ti mixed system were discussed. From the aspect of thermal effect, owing to the heterogeneous interface introduced by titanium particles, polarization loss would happen at the interface layer. Both polarization loss and eddy current loss contributed to the promotion of sintering. And from the aspect of non-thermal effect, there would be a gradient of microwave field at the heterogeneous interface resulted from the different microwave skin depth of intermetallic compounds and pure metal. Mass diffusion was supposed to be accelerated due to the electromagnetic field gradient.