Wear properties of sintered WC-12%Co processed via Binder Jet 3D Printing (BJ3DP)

A study was carried out to evaluate the wear properties of Binder Jet 3D Printed (BJ3DP) WC-12% Co per the ASTM B611 and G65 test methods. The printed samples were sintered under a pressure of 1.83 MPa at 1485 °C for 5 min to achieve near theoretical densities. A dual WC grain size was observed in the microstructure of the sintered parts. The microstructure largely consists of 1.4-2.0 μm WC grains and clusters of coarse grains ranging in size up to ~ 20 μm in the Co matrix. The samples showed a volume loss of 140.48 ± 2.73 mm3during the B611 testing. The wear resistance of the samples was found to be superior to that of standard cemented carbides with similar amount of Co. The superior wear resistance is attributed to the dual grain size microstructure. The SEM micrographs of the wear surfaces after B611 testing showed the fragmentation and pull out of WC and substantial wear of the Co matrix. The G65 wear testing showed a volume loss of 3.67 ± 0.66 mm3. The SEM micrographs of the wear surfaces after the G65 testing showed wear occurring primarily in the Co matrix. The results from the present study confirm the feasibility of the BJ3DP process to fabricate WC-12%Co parts with superior wear resistance properties.