Hard alloy with double-layer gradient structure on surface and making method for hard alloy

Abstract

The invention belongs to the technical field of hard alloys, and particularly relates to a hard alloy with a double-layer gradient structure on the surface and a making method for the hard alloy. The hard alloy comprises a first gradient layer, a second gradient layer and a core part from the outside to the inside; the first gradient layer does not contain a cubic phase; the second gradient layer contains the cubic phase; the core part contains the cubic phase; the content of a binding phase in the first gradient layer is higher than the average content of the binding phase in the hard alloy; and the content of the binding phase in the second gradient layer is lower than the average content of the binding phase in the hard alloy. The making method is characterized in that a tungsten source, a cobalt source, a titanium source, a tantalum source, a niobium source, a zirconium source, a hafnium source and a carbon source are prepared according to designed components; the prepared raw materials are added into a ball mill for wet milling, and then are dried and compression moulded to obtain a compacted blank; and the compacted blank is subjected to two-stage sintering to obtain the hard alloy with the double-layer gradient structure on the surface. The hard alloy is reasonably in structure design; the making technique is simple and controllable; and large-scale industrial application is convenient.

Description

technical field [0001] The invention belongs to the technical field of hard alloys, in particular to a hard alloy with a double-layer gradient structure on the surface and a preparation method thereof. Background technique [0002] Cemented carbide is a kind of cermet tool material prepared by powder metallurgy method with refractory metal compounds (WC, TiC, TaC and NbC, etc.) as the matrix and transition metals (Co, Fe, Ni) as the binder phase. . Cemented carbide has the advantages of high strength, high hardness, high elastic modulus, wear resistance, corrosion resistance, low thermal expansion coefficient and high chemical stability. It is known as "industrial teeth" and is widely used as cutting tools and drilling tools , Wear-resistant parts, etc. With the rapid development of modern industry, higher requirements are put forward for the performance of cemented carbide cutting tools. In order to improve the service life and cutting performance of cemented carbide cut...

AI Technical Summary

Problems solved by technology

With the more systematic and in-depth research work, the comprehensive performance of gradient cemented carbide materials without β layer is still improving, but no new gradient structure has been proposed on the basis of the existing β layer.

At the same time, it was found through searching that: at present, there is no special research on the preparation of cemented carbide with a new gradient structure on the basis of the existing β-layer gradient cemented carbide by using the cubic phase solubility gap.

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