Space-resolved study of binder burnout process in dry pressed ZnO ceramics by neutron imaging

A novel non-destructive space-resolved method for studying binder burnout is presented. Debinding of dry pressed zinc oxide green bodies was analyzed by neutron imaging. Neutrons in contrast to X-rays allow penetrating samples with large dimensions up to 80 mm and at the same time detecting variations in the organics content as small as 0.1 wt%. We used neutron radiography (2D) and tomography (3D) to investigate with a spatial resolution in the order of 100 μm the distribution of binder during burnout under three different conditions. First a reference case with green bodies placed on a plate in a lab furnace. Second, a configuration with a reduced volume of air with green bodies enclosed in a sagger and third a green body placed on an improved supporting structure. The method is extendable to other particulate materials and green bodies shaped by processes involving organic binder such as casting, extrusion and injection.