Sintering of WC-12%Co processed by binder jet 3D printing (BJ3DP) technology

A study was carried out to evaluate the sintering densification, shrinkage and mechanical properties of WC-12%Co powders processed by binder jet 3D printing (BJ3DP). After debinding, vacuum sintering at 1435-1485 °C for 45 min yielded low sintered densities in the range of 13.1-13.5 g/cm3. Near theoretical densities of 14.1-14.2 g/cm3 were achieved by sintering the parts under a pressure of 1.83 MPa at 1485 °C for 5-30 min. Shrinkage in the range of 22.2-24.4% and 20.9-26.2% was observed in the parts sintered in vacuum and under pressure, respectively. The samples densified to near theoretical density showed hardness of 1256 HV30 and fracture toughness of 17 ± 1 MPa m1/2. The hardness and fracture toughness are in line with the properties of conventionally produced WC-12%Co with medium grain size. The results from the present study confirm the suitability of the binder jet 3D printing (BJ3DP) process to manufacture WC-Co parts with good mechanical properties.