STUDY OF THE INFLUENCE OF MECHANOACTIVATION ON THE MORPHOLOGY AND PHASE COMPOSITION OF WC-FE POWDERS

Abstract

This study presents a comprehensive investigation into the effect of mechanical activation (MA) on the morphological and phase characteristics of WC-Fe powders intended for the production of next-generation hardmetal composites. In the context of sustainable development and the need to replace cobalt as a toxic and scarce binder, the WC-Fe system is considered a promising alternative to conventional WC-Co materials. The experimental part includes analysis of two compositions — 88 wt.% WC-12 wt.% Fe and 95 wt.% WC-5 wt.% Fe subjected to high-energy MA in a planetary ball mill (500 rpm) for 1, 2, and 4 hours. The powder morphology was studied by SEM, phase composition by XRD, and particle size distribution by laser diffraction. The results revealed that significant crystallite size reduction (~220 Å), increased dislocation density, and the formation of amorphous regions occur at early stages of MA (1-2 h). In systems with higher Fe content, the formation of a secondary W₂C phase was observed, indicating intensified solid-state reactions. Increased Fe content enhances dispersibility and reduces agglomeration, whereas 95 wt.% WC systems exhibit a tendency for aggregation and partial sintering during prolonged milling. The optimal balance between fragmentation and agglomeration was achieved at 1-2 hours of MA. Further treatment led to secondary agglomeration and degradation of powder properties. The findings demonstrate the critical dependence of phase evolution and morphological uniformity on system stoichiometry and MA duration, and can be used to optimize powder preparation parameters for the development of cobalt-free wear-resistant WC-based materials with tailored structural and mechanical properties.