DIN EN ISO 4499-2:2010-10

The text of ISO 4499-2:2008 has been prepared by Technical Committee ISO/TC 119 "Powder metallurgy" of the International Organization for Standardization (ISO) and has been adopted as EN ISO 4499-2:2010. The responsible German committee is Working Committee NA 145-01-04 AA "Probenahme und Prüfverfahren für Hartmetalle" ("Sampling and testing methods for hardmetals") of the Technology of Materials Standards Committee (NWT). This standard provides guidelines for the measurement of hardmetal grain size by metallographic techniques using exclusively optical and electron microscopy. This standard is intended for sintered WC/Co hardmetals (also called cemented carbides or cermets) containing primarily WC as the hard phase. It is also intended for measuring the grain size and distribution by the linear-intercept technique. This standard essentially covers four main topics: - calibration of microscopes to underpin the accuracy of measurements; - linear analysis techniques to acquire sufficient statistically meaningful data; - analysis methods to calculate representative average values; - reporting, to comply with modern quality requirements. In this standard the recommended techniques are illustrated by a (measurement) case study. This part of ISO 4499 is not intended for the following: - Measurements of size distribution; - Recommendations on shape measurement. Further research is needed before recommendations for shape measurement can be given. Measurements of coercivity are sometimes use for grain-size measurement, but this current guide is concerned only with the metallographic measurement method. It is also written for sintered hardmetals and not for characterising powders. However, the method could, in principle, be used for measuring the average size of powders that are suitably mounted and sectioned. With respect to DIN ISO 4499:1991-07, information about the measurement of the WC grain size of hardmetals has been added.