Preparation and mechanical properties of WC-10 Ni3Al cemented carbides with plate-like triangular prismatic WC grains

The elemental powder mixtures of Ni, Al, Fe, Cr, Zr and B in the proportion Ni-10.50 Al-10.90 Fe-8.12 Cr-0.89 Zr-0.21 B (wt.%) were synthesized into Ni3Al by high-energy ball milling. The alloyed Ni3Al powders were then added to WC powders with a nominal stoichiometry of WC-10 wt.% Ni3Al and underwent further milling. Finally the milled WC-10 wt.% Ni3Al powders were fabricated into unusual alloys with obviously oriented plate-like triangular prismatic WC grains by spark plasma sintering (SPS) in the sintering temperature range of 1300–1400 °C. The effect of sintering temperature on the microstructures and mechanical properties was also investigated. The results indicate that a proper temperature of 1350 °C will help to obtain obviously oriented plate-like triangular prismatic WC grains with a high axial ratio. The obtained bulk WC-10 wt.% Ni3Al possesses a high hardness (HV10), transverse rupture strength and fracture toughness of 17.76 GPa, 2092 MPa, 21.56 MPa m1/2, respectively.

► The Ni–Al–Fe–Cr–Zr–B powder mixtures are synthesized into Ni3Al by milling.
► WC–Ni3Al alloys with oriented plate-like WC grains are fabricated by SPS.
► The existence of plate-like WC grains helps toughen the alloys.
► The optimal alloy has a HV10 of 17.76 GPa, TRS of 2092 MPa, KIc of 21.56 MPa m1/2.