Effect of densification mechanism on the Σ2 grain boundary plane distribution in WC–Co composites

The effect of the densification mechanism on the Σ2 grain boundary plane distribution was investigated in WC–Co composites. Specimens were prepared separately by sintering in hot isostatic press (sinter-HIP) and spark plasma sintering (SPS). It was found that the Σ2 twist boundary is the most common boundary in both cases, but that the SPS material had more than three times the relative area of these boundaries compared to the sinter-HIP material. Measurements of the WC/WC and WC/Co boundary lengths are compared to measured mechanical properties and found to be consistent with established stereological results, suggesting a path to link interface area measurements to the mechanical properties of WC–Co samples.

► The Σ2 grain boundary plane distribution in WC–Co processed by SPS and sinter-HIPing is compared.
► The SPS material has three times more Σ2 grain boundaries than the sinter-HIP material.
► A path to link interface area measurements to the mechanical properties of WC–Co is suggested.