OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 24 No. 1 2022 Fig. 6. Microstructure of the sintered tungsten agglomerates (see Table 2). Obviously, this is associated with hardening of the intermetallic compound by fi nely dispersed tungsten particles. The sintered material containing tungsten not exposed to mechanical activation has the macrohardness of 101–102 HRB. Meanwhile, the material with mechanically activated tungsten features the higher hardness of 105–107 HRB, which is associated with work hardening of tungsten particles and dispersion hardening of other structural constituents. Conclusions 1. The effect of mechanical activation on the morphology of particles and fi neness of the W16,5 grade tungsten powder has been studied. In the examined modes, mechanical activation is accompanied by the formation of tungsten nanoparticles with the minimum size of 25 nm. Alongside this, the powder is exposed to work hardening, which hinders further milling. 2. With its high surface energy, tungsten nanoparticles produce a noticeable effect on cobalt dissolving and depositing in liquid phase sintering of the Sn-Cu-Co-W powder material. Introducing nanodispersed tungsten into the material slows down the growth of cobalt particles and helps to obtain a fi ne-grained structure. 3. The sintered Sn-Cu-Co-W material containing mechanically activated tungsten features higher hardness of 105–107 HRB, which is explained by work hardening of tungsten particles and dispersion hardening of other structural constituents. References 1. Konstanty J. Powder metallurgy diamond tools. Oxford, Elsevier, 2005. 152 p. ISBN 978-1-85617-440-4. DOI: 10.1016/B978-1-85617-440-4.X5077-9. 2. Novikov M.V., Mechnyk V.A., Bondarenko M.O., Lyashenko B.A., Kuzin M.O. Composite materials of diamond−(Co–Cu–Sn) system with improved mechanical characteristics. Part 1. The infl uence of hot re-pressing on the structure and properties of diamond−(Co–Cu–Sn) composite. Journal of Superhard Materials, 2015, vol. 37, pp. 402–416. DOI: 10.3103/S1063457615060052.
RkJQdWJsaXNoZXIy MTk0ODM1