WC/Co-composite powders via hydrothermal reduction of Co3O4-suspensions
Source abstract
Abstract
Abstract Due to the strong influence of the cobalt distribution in the green powder compact on the quality of the sintered hardmetal alloy, intensive powder milling and a balanced ratio of WC to Co powder particle size are usually required to achieve uniform carbide-microstructures. In the past many attempts have been made to reduce or avoid powder milling and to improve the quality of the powder mixture by chemical means. The research described below focused on a new route to carbide coating comprising oxide-pressure-precipitation of submicron to nano-sized Co 3 O 4 -suspensions from cobalt solutions, mixing with WC-suspensions and subsequent hydrothermal reduction of those suspensions in hydrogen atmosphere. The effects of WC addition and catalyst addition on the progress of cobalt oxide reduction are discussed. The resulting cobalt and composite powders were characterised via powder diffraction, SEM and TEM imaging. Sintering tests confirmed the uniform Co distribution.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (29)
Show source-provided references
1. Effect of cobalt size on the processing and properties of fine-grained WC/Co materials
2. Carroll DF, Järvi J. Granulated cobalt powders for WC/Co materials. In: Kneringer G, Rödhammer P, Wilhartitz P, editors. Proceeding of the 15th international plansee seminar 2001, vol. 2. Plansee Holding AG. p. 15–28.
3. Schubert WD, Bock A, Lux B. General aspects and limits of conventional ultrafine WC powder manufacture and hardmetal production. In: Kneringer G, Rödhammer P, Wilhartitz P, editors. Proceeding of the 13th international plansee seminar 1993, vol. 4. Plansee Holding AG. p. 283–305.
4. Synthesis of ultrafine WC/Co powder by mechanochemical process10.1179/003258902225001506 ↗
5. Preparation of tungsten carbide-cobalt powder by direct carburization of tungsten trioxide in the presence of cobalt oxide (Co3O4)
6. A new continuous process for production of tungsten carbide-cobalt mixed powder by rotary kilns
7. Alternative approach to the manufacture of ultrafine grained hardmetal powders
8. Meissl C, Edtmaier C, Schubert WD, Schön A, Bock A, Zeiler B. Sintering of tungsten carbide–cobalt composite powders. In: Kneringer G, Rödhammer P, Wildner H, editors. Proceeding of the 16th international plansee seminar 2005, vol. 2. Plansee Holding AG. p. 631–40.
9. Sherman AJ, Bose A. Manufacture of fine tungsten carbide powders coated with a grain-growth inhibitor and then binder metal for sintering. US6641918 B1; 2003.
10. Weber T. Coating hard powder particles electrolytically with a softer metal. US3428543; 1969.
11. Kunda W, Randell DA. Cobalt-coated composite powder. US3730756; 1973.
12. A study of the cobalt coating on tungsten carbide powder by hydrogen reduction methode
13. Preparation and evaluation of tungsten carbide cobalt composite powders by chemical methods
14. Towanda JER, Sayer JSL. Process for coating tungsten carbide with cobalt metal. US4801472; 1989.
15. Andersson S, Bonneaux M, Chardon N, Muhammed M. Methode of making metal composite powders. WO95/26843; 1995.
16. Bonneaux M, Chardon N, Andersson S, Muhammed M. Methode of making metal composite powders. US5529804; 1996.
17. Andersson S, Muhammed M. Methode of making metal composite powder. WO79/11805; 1997.
18. Mende B, Gille G, Lamprecht I. Powder mixture or composite powder, its production, and use in composites. EP1242642B1; 2000.
19. Veitsch C, Meissl C, Edtmaier C, Schubert WD, Schön A, Bock A, et al. Coating of tungsten carbide powders with cobalt. In: Kneringer G, Rödhammer P, Wildner H, editors. Proceeding of the 16th international plansee seminar 2005, vol. 2. Plansee Holding AG. p. 528–39.
20. Fischer U, Waldenström M, Ederyd S, Nygren M, Westin G, Ekstrand Å. Methode of making metal composite materials. US5505902; 1996.
21. Ekstrand ÅB, Westin LG. Highly homogeneous WC-Ni/Co-composites produced from WC-powder coated with a solution chemical route. CIMTEC; 2002, 2003, Part C. p. 489–96.
22. Carrol DF, Jarvi J. Methods of producing composite powders. US0097907 A1; 2003.
23. Anderson PA, Edmondson MJ. Coated metallurgical particles. WO2004/026509 A1; 2004.
24. The continuous hydrothermal synthesis of nano-particulate ferrites in near critical and supercritical water10.1039/b009428p ↗
25. Rapid and continuous hydrothermal crystallization of metal oxide particles in supercritical water10.1111/j.1151-2916.1992.tb04179.x ↗
26. Bismuth-enhanced electro-chemical stability of cobalt hydroxide used as an additive in Ni/Cd and Ni/metal hydride batteries10.1149/1.1393491 ↗
27. Réactions de solides divisés faisant intervener des oxides et hydroxides de cobalt
28. Fletcher E et al. Cobalt monograph. Centre d’information du cobalt. Brüssel; 1960.
29. Study of hydrogen oxidation on carbides10.1016/0013-4686(91)85004-Q ↗