WC-Co (Wolfram Carbide-Cobalt) hard alloy with Ta/Nb (Tantalum/Niobium) solid solution dispersedly distributed and preparation method thereof

Abstract

The invention discloses a WC-Co (Wolfram Carbide-Cobalt) hard alloy with Ta / Nb (Tantalum / Niobium) solid solutions dispersedly distributed and a preparation method thereof. The WC-Co hard alloy comprises a WC hard phase, a metal Co binder phase and a Ta / Nb solid solution phase, wherein the mass fraction of the metal Co binder phase is a more than or equal to 3% and less than or equal to 15%; the Ta / Nb solid solution phase comprises at least one of a TaC (Tantalum Carbide ) solid solution, an NbC (Niobium Carbide) solid solution or a (Ta, Nb)C solid solution, and (mTa+mNb) / mCo is more than or equal to 0.004 and less than or equal to 0.083; and Ta / Nb solid solutions are dispersedly distributed in a point shape in the WC-Co hard alloy. The preparation method of the WC-Co hard alloy comprises the following steps of: preparing a semi-finished product; and carrying out sintering temperature rise, sintering heat preservation and sintering cooling on the semi-finished product. The WC-Co hard alloy disclosed by the invention realizes the dispersed distribution of the TaC, NbC or (Ta, Nb) C solid solutions on the basis without changing alloy components, thereby enhancing the alloy structure uniformity and the alloy property.

Description

technical field [0001] The invention relates to a WC-Co hard alloy, in particular to a WC-Co hard alloy with dispersed Ta / Nb solid solution and a preparation method thereof. Background technique [0002] Fine-grained carbide inserts and coated inserts based on them are widely used in the field of metal cutting. The fine-grained cemented carbide insert matrix is ​​generally sintered by powder metallurgy process, which is mainly composed of metal carbide hard phase (such as WC), metal binder phase (such as Co) and grain growth inhibitor. However, since the main grain growth inhibitors currently used are metal carbides such as Ta, Nb, Cr, V, Ti, etc., or metal carbide solid solutions of two or more combinations thereof, these metal carbides and their solid solutions are different from The wettability of the cemented carbide binder phase Co is not as good as that of WC, so the addition of grain growth inhibitors is detrimental to the alloy strength. [0003] For fine-grained c...

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Problems solved by technology

However, using this complex carbide and controlling the content of metal elements will significantly increase the cost of raw materials on the one hand, and on the other hand, the addition of elements such as Ti, Zr, Hf and V will significantly change the alloy composition, which will have some adverse effects on performance. influences

[0006] At present, there is no report on the elimination of TaC, NbC or (Ta, Nb)C solid solution aggregation in such alloys without changing the alloy composition.

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