Preparation of spheroidized W-Cu pseudo-alloy micropowder with sub-micrometer particle structure using plasma technology
(1. Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Moscow 119334, Leninsky prospect 49, Russian;
2. Federal Scientific Research Center “Crystallography and Photonics”, Russian Academy of Sciences, Moscow 119334, Leninsky prospect 59, Russian)
2. Federal Scientific Research Center “Crystallography and Photonics”, Russian Academy of Sciences, Moscow 119334, Leninsky prospect 59, Russian)
Abstract: The possibility to obtain composite micropowders of the W-Cu system with spherical particles having sub-microscale/nanoscale internal structure was confirmed and studied using the complex multistage approach. Composite W-Cu nanoparticles with core–shell structure (W cores and Cu shells) were produced in plasmochemical synthesis in the first stage. Further spray-drying of the aqueous suspension of the W-Cu nanopowder with sucrose enabled the formation of 25-63 μm microgranules with a yield of 50%. The last step was the treatment of the nanopowder microgranules by a thermal plasma jet, which ensured the production of dense spherical W-Cu particles. The final powder had a spheroidization degree of 90%-95%, a bulk density of up to 8.1 g/cm3 and a flowability of 12 s/50 g. The contents of impurities in the resulting spherical micropowder were 0.7 wt.% O, 0.02-0.2 wt.% C and 0.03-0.05 wt.% H.
Key words: W-Cu composites; plasmochemical synthesis; granulation; plasma spheroidization; nanoparticles; microgranules; micropowders