Determination of microstructural characteristics of nanostructured cemented carbides

In recent times, the development of cemented carbides is based on the application of ultrafine and nano grain size powder particles. Sintering such powders significantly improves the properties of the final product and enables the use of tools at higher cutting speeds with a longer service life. In this article, sintering procedure for nanostuctured cemented carbide tools with 10 wt. % Co and 90 wt. % WC was carried out. The characteristics of the initial powder mixture and the sintering process are described. By measuring the density of the sintered sample and microstructural analysis of the polished surface, 100 % of the theoretical density without the presence of pores and unbound carbon was determined. The nano size of the carbide grain was confirmed by scanning electron microscopy. By measuring the magnetic saturation it was confirmed that the sample doesn't contain unwanted microstructural defects such as η-phase and unbound carbon and by measuring the coercitive forces it was also confirmed that the WC grains remained in the nano-sized range.