Influence Of Binder Characteristics On Binder Saturation And Wetting Behavior In Metal Binder Jetting

Metal Binder Jetting (MBJ) has an increasing attention in Additive Manufacturing because of its serial production potential. The aim of this work is to get a better understanding of the powder-binder-interaction for better process control and consequently a reduction in the number of iteration stages in material-specific process development, which saves costs, effort as well as material resources and printing capacity. Depending on the binder characteristics, the equilibrium saturation and wetting behavior changes. A better understanding of binder viscosity and surface tension on the powder-binder-interaction will improve the part quality. A suitable parameterization of the MBJ printing processes for specific powder-binder combinations, based on the binder and powder characteristics as well as the powder-binder interaction will improve the part density, accuracy and surface quality. The results show that, depending on the binder characteristics, the equilibrium saturation and wetting behavior changes. A higher surface tension seems to cause a higher equilibrium saturation and a lower saturation rate. The effect of the surface tension on the initial wetting time was overlaid by the effect of the surface chemistry. A higher viscosity leads to a significant higher initial wetting time on the powder bed surface, significant higher equilibrium saturation and a significant lower saturation rate. The relationship between wetting behavior and printing parameters as well as the effect of drying and droplet impact must be investigated further in subsequent studies.