Nanocrystalline cobalt powders have been prepared from aqueous solution by reducing their corresponding metal salts under suitable conditions. The experimental conditions have been studied in detail. X-ray powder diff...Nanocrystalline cobalt powders have been prepared from aqueous solution by reducing their corresponding metal salts under suitable conditions. The experimental conditions have been studied in detail. X-ray powder diffraction patterns show that the cobalt powder is hexagonal crystallite. The average particle size of the ultrafine cobalt powder is 55 nm.展开更多
Hardmetals are tungsten carbide(WC)-based composites,which are made of WC as a hard phase and transition metals such as Co,Fe,or/and Ni as ductile binder matrices.Their properties can be mainly tailored through the gr...Hardmetals are tungsten carbide(WC)-based composites,which are made of WC as a hard phase and transition metals such as Co,Fe,or/and Ni as ductile binder matrices.Their properties can be mainly tailored through the grain sizes of the sintered carbides and the amount of metallic binder.As successful tool materials,hardmetals are widely applied in metal cutting,wear applications,chipless forming,stoneworking,wood,and plastic working.In 2017,about two-thirds of tungsten consumption(including recycled materials)were produced for hardmetals in the world.This paper briefly introduces the development of manufacturing technology on WC-Co hardmetals from three aspects:powder preparation,bulk densifica-tion,and performance characterization.Two special WC-Co hardmetals are also described:cobalt-enrichment zone(CEZ)hardmetals,and binderless hardmetals.Furthermore,the development prospects for manufacturing techniques of hardmetals are also presented in the end.展开更多
基金Blazing A New Trail through Science and Technology Foundation" of Northwest Normal University and Educational Committee Founda
文摘Nanocrystalline cobalt powders have been prepared from aqueous solution by reducing their corresponding metal salts under suitable conditions. The experimental conditions have been studied in detail. X-ray powder diffraction patterns show that the cobalt powder is hexagonal crystallite. The average particle size of the ultrafine cobalt powder is 55 nm.
基金the Major Special Projects of Fujian Science and Technology Plan(Grant No.2017HZ0001-1)。
文摘Hardmetals are tungsten carbide(WC)-based composites,which are made of WC as a hard phase and transition metals such as Co,Fe,or/and Ni as ductile binder matrices.Their properties can be mainly tailored through the grain sizes of the sintered carbides and the amount of metallic binder.As successful tool materials,hardmetals are widely applied in metal cutting,wear applications,chipless forming,stoneworking,wood,and plastic working.In 2017,about two-thirds of tungsten consumption(including recycled materials)were produced for hardmetals in the world.This paper briefly introduces the development of manufacturing technology on WC-Co hardmetals from three aspects:powder preparation,bulk densifica-tion,and performance characterization.Two special WC-Co hardmetals are also described:cobalt-enrichment zone(CEZ)hardmetals,and binderless hardmetals.Furthermore,the development prospects for manufacturing techniques of hardmetals are also presented in the end.
