Analysis of WC grain growth during sintering using electron backscatter diffraction and image analysis

The WC carbide grain size is important for the technological properties of cemented carbide cutting tools. In the present work the WC carbide grain size distribution is determined after milling and sintering for 0.25, 1 and 8 h at 1430 °C.The WC grain size distribution, both for the powder after milling and the sintered specimens, is determined by two different methods, i.e. image analysis on scanning electron microscopy (SEM) images and electron backscatter diffraction (EBSD). It should be noted that in this work the 2D grain size distribution is considered.The EBSD analysis clearly shows that the special Σ2 boundaries are present in the powder and that their fraction decreases during sintering and particularly during the early stages. When the Σ2 boundaries are omitted in the EBSD analysis the results of the grain size measurements for the two methods agree quite well.