Spark Plasma Sintered WC-Ni Cemented Carbides with Various Contents of ZrC Nano-Powder

Abstract

WC-10Ni cemented carbides with various contents (0-9 wt.%) of ZrC nanopowder were fabricated by spark plasma sintering at 1350 °C with a pressure of 50 MPa. The phase composition, microstructure and mechanical properties of the as-prepared samples were investigated. X-ray diffraction analysis revealed that excepting WC hard phase, a solid solution phase Ni (W,Zr) with different amounts of individual metal was formed with increasing ZrC nanopowder content. Scanning electron microscopy examination indicated that a proper addition content of ZrC can suppress the abnormal growth of WC grains and improve the relative density of WC-Ni cemented carbides. However, with further increase in the content of ZrC (more than 7 wt.%), the agglomeration of ZrC became more and more serious. The samples with 5 wt.% ZrC nanopowder possess a relative higher flexural strength (~1750 MPa) among all the investigated samples. When the addition content of ZrC nanopowder was 3 wt.%, the Vickers hardness of the samples reached its maximum value (~1810 HV10).