Angularity evaluation of milled WC-Co powder

Technological properties of powders depend on their granularity and powder particle morphology. The grindability of hardmetal powder, the dynamics of milling and changes in particle granularity and morphology were studied. For particle morphology analysis, the irregularity parameter as well as particle roundness and aspect ratio were found out. In order to characterise the granularity, the mean particles size was measured and volume distribution function, median size and probability density function of the particles volume were calculated. For describing the angularity of milled powders, so-called "spike parameter – quadratic fit" (SPQ) was properly described and real experiments for determination of SPQ sensitivity and precision to characterise particles angularity were performed. Using the coefficients of variation for SPQ and particle shape parameters, the dispersions changes in dependence on the milling duration was investigated. Experiments for determination the influence of hardmetal particles angularity to erosion rate of different metallic materials show the essentiality of this parameter in powders shape characterisation.