A kind of wc-co-re composite powder and its preparation method and application

Abstract

The invention provides WC-Co-RE compound powder and a preparation method and application thereof and belongs to the technical field of hard alloys. The preparation method comprises the following steps: mixing a soluble cobalt salt aqueous solution with a soluble rare earth salt aqueous solution to obtain a mixed solution; adjusting an ammonium tungstate aqueous solution to be acidic to carry out aprecipitation reaction with carbon powder and the mixed solution, and drying the mixture to obtain mixed powder; and in a protecting atmosphere, carrying out decomposing and reducing reactions successively on the mixed powder and cooling the mixed powder to obtain the WC-Co-RE compound powder. The grain size of the WC-Co-RE compound powder can be reduced effectively and the dispersity of rare earth elements can be improved effectively by means of the preparation method, and meanwhile, the problem of easy oxidization as the rare earth elements are doped in a conventional hard alloy preparationprocess is solved.

Description

technical field [0001] The invention belongs to the technical field of cemented carbide, and in particular relates to a WC-Co-RE composite powder and a preparation method and application thereof. Background technique [0002] The traditional WC-Co cemented carbide preparation process is generally obtained by pressing and sintering solid raw materials after ball milling, which is prone to problems such as poor wettability and grain growth, which further deteriorates the mechanical properties of the composite material. The study found that the addition of rare earth can inhibit the martensitic transformation of α-Co to ε-Co in the WC-Co cemented carbide binder phase, solid solution strengthen the binder phase, improve the wettability of the binder phase to the carbide phase, and fine Hard phase organization, purification of grain boundary, phase boundary, and then improve the bending strength, impact toughness and durability of cemented carbide. [0003] However, due to the h...

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Problems solved by technology

Among them, the addition of rare earth oxides in solid form can improve the thermal strength of the alloy, but it may reduce the thermoplasticity and toughness; the addition of pure rare earth elements in powder form is difficult to ensure uniform dispersion due to the small amount of addition, and more importantly, the preparation In the process, rare earth powder oxidation is difficult to control and other problems; rare earth hydrides and nitrides also have similar problems such as oxidation and instability; rare earth-cobalt master alloy powder has a single composition, uneven distribution of rare earth elements, coarse particle size, and easy oxidation, etc. problems; these problems have seriously affected the application of rare earth elements in cemented carbide at the current stage

To sum up, no matter what kind of rare earth elements are added in the traditional solid-phase mixing preparation process, it is easy to produce defects and deficiencies such as uneven dispersion and easy oxidation during the doping process of cemented carbide.

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