Grain size measurement methods and models for nanograined WC-Co

Development of nanograined WC-Co presents challenges for grain size measurement. In this study, standard and nanocrystalline WC-Co powders are processed by conventional and spark sintering. The resulting microstructures are characterized by image analysis of scanning electron microscopy micrographs, X-ray line broadening, and magnetic coercivity. The results are analyzed and a property map relating coercivity to WC grain size is developed. Equations for interface-controlled grain growth are transformed into the master sintering curve form and are used to analyze the grain size data from the three measurement techniques.