Investigation of binder jet 3D printing parameters of WC-Co using design of experiments

Binder Jet Printing (BJT) powder feedstock conventionally used for press-and-sintered applications can be advantageous to easily integrate the new technology into current manufacturing routes, while enabling more complex geometries. In this study, BJT of un-sintered WC-Co powder (General Carbide) was studied through a systematic Design of Experiments to explore the impact of print parameters on green and sintered densities. Although the powder feedstock′s low-packing fraction has a dominant effect over spreading parameters, the linear interaction between binder saturation and drying time print parameters also significantly influences the green ( R 2 = 30%) and sinter-HIPped densities ( R 2 = 14%). The sinter-HIP properties revealed a maximum density of 97.8 ± 1.8% and 1310.4 ± 51.6 HV Vickers hardness, in range for the WC grade (fine-medium grain size, 1.2 ± 0.8 μm) and composition (∼12 wt.% Co). However, high porosity of the green samples promoted Co-pooling and consequently excessive indentation fracture toughness (20.5 ± 7.5 MPa·m 1/2 ) and magnetic saturation (19.9 emu/g).