GRAIN SIZE MEASUREMENT METHODS AND MODELS FOR NANOGRAINED WC-CO

Abstract

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. (C) 2007 Elsevier Ltd. All rights reserved.