Consolidation of WC–Co alloys by magnetic pulsed compaction and evaluation of their mechanical properties

In this study, magnetic pulsed compaction (MPC), a very short duration, high-density preform molding method was used to produce bulks from initial WC–7.5 wt.% Co and WC–12 wt.% Co with varied consolidation conditions, followed by subsequent sintering. Mechanically alloyed powders with compositions of WC–7.5 wt.% Co and WC–12 wt.% Co were used and combinations of pressures of 0.5G Pa, 1.0 GPa, 1.5 GPa, 2.0 GPa, 2.5 GPa and 3 GPa were applied to form the bulks. Maximum densities for WC–7.5 wt.% Co and WC–12 wt.% Co after magnetic pulsed compaction were found to be around 70%, which later turned nearly 92% after sintering, while a maximum hardness of over 1430 Hv was observed in WC–12 wt.% Co sample. Density, hardness and crack length all suggested a gradual pattern or trend in MPC-ed bulks that can yield almost fully dense, commercially applicable products with high mechanical properties after sintering.

Field emission scanning electron microscopy (SE) showing changes in crack length of MPC + sintered WC–12 wt.% Co samples at different pressures (a) 2.5 GPa (3 times), (b) 3 GPa (3 times), (c) 0.5 + 2.5 + 3 GPa, (d) 0.5 + 3 + 3 GPa, (e) 1.5 + 2.5 + 3 GPa and (f) 1.5 + 3 + 3 GPa.Figure optionsDownload as PowerPoint slideHighlights
► New magnetic pulsed compaction process was used on two WC–Co compositions.
► MPC process was used prior to sintering with a wide range of pressure combinations.
► MPC's effect on mechanical properties and microstructural behavior was discussed.
► Relationship between improved properties and MPC process was tried to establish.
► Prospects were highlighted on how MPC process can aid commercial sintering.