Effect of milling temperature on the synthesis and consolidation of nanocomposite WC–10Co powders

Abstract

Abstract The effect of milling temperature on the synthesis of WC–10Co powders was investigated by mechanical alloying carried out at −30 °C and room temperature (RT). X-ray diffraction (XRD) showed that WC domain size was reduced to 26 nm after 1 h cyclic milling at −30 °C and 21 nm after 1 h RT milling. The morphology of the milled powders was determined by scanning electron microscopy (SEM) and this showed that particles from −30 °C milling had increased deformation and less irregularity. Differential scanning calorimetry (DSC) of the low temperature milled powder showed a greater enthalpy release. The powder milled at −30 °C exhibited a relative density of 65.5% after cold compaction at 400 MPa pressure compared to 64% for the RT milled powder. Both powders were consolidated by using pressureless sintering and sinter-HIP techniques. The powders milled at −30 °C and RT achieved a maximum hardness of 13.5 GPa and 12.7 GPa, respectively.