Microstructural evolution during sintering of cermets studied using interrupted sintering experiments and novel 2D and 3D FESEM based techniques

During sintering of cermets the dissolution and precipitation of dissolved MeCs lead to the well-known formation of a core-rim structure. To investigate the microstructural evolution during sintering the sintering process was interrupted at different temperatures and the formation of the core-rim structure traced. EDS mappings and point scans as well as 3D-FIB tomography scans were carried out to study the distribution of added MeCs like Mo2C or WC on ion-beam prepared samples. The studied cermet consisted of a Ti(C,N) hard phase with a mixed Co and Ni binder and added Mo2C. The results show i.e. that within the rim area not only a high amount of MeC exists, but also that during the final stages of sintering in some grains binder inclusions within the rim area and Mo inclusion within the core appear.