Basal body for composite structure hard alloy

Abstract

The invention discloses a carbide alloy base body taking TiC- WC or WC as hard phase and used for continuous interface composite construction. It comprises hard phase and adhesive phase, said hard phase is TiC- WC or WC, and said adhesive phase is Ni compound. The base body is added with part of WC-Co- containing prelacy powder made from regenerative hard alloy to reuse W and Co, and base body is added with a large part of hard phase (TiC) and Ni compound to reduce W and Co consumption, the adhesive phase Ni compound combines with adhesive phase Co through intermolecular linkage to make the composite interface transite continuously without foreign matter generation, no slit and carbon elimination, gash and stratification. So the carbide alloy base body is characterized by wide application and good comprehensive performance, which is the same to that of normal single layer hard alloy.

Description

Technical field [0001] The invention belongs to the field of cemented carbide material preparation, and in particular provides a cemented carbide matrix with TiC-WC or WC as the hard phase for continuous interface composite structure. Background technique [0002] The commonly used cemented carbide is a single layer structure, and its composition consists of a hard phase (such as WC, WC-TiC, etc.) and a binder phase (such as Co, Co+Ni, etc.). This single layer structure is composed of Phase metal molecular bonds interact to form a continuous transitional whole, which has the characteristics of wide application and good comprehensive performance. In the actual use process of cemented carbide, the use part that is used to process the workpiece and is consumed only accounts for a small part of the entire cemented carbide volume. This part is called the used layer, which acts as a supporting lining to give the cemented carbide a certain shape. The overall non-used part of the size ac...

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Problems solved by technology

[0004] However, the key to the quality of composite cemented carbide lies in the interface bonding mechanism between the substrate and the use layer. There are generally two aspects that affect the combination of the substrate and the use layer: First, the large difference in characteristics between the substrate and the use layer leads to poor bonding: the current conventional It is easy to obtain and low-cost steel, alloy steel, steel-bonded hard alloy and other materials with little or no W and Co as the matrix, but because these matrixes are alloys formed by adding other elements or compounds mainly to Fe, There is a large difference in the composition of the cemented carbide formed by adding a binder phase mainly to the hard phase, resulting in a large difference in the properties of the substrate and the cemented carbide layer. The most important characteristic difference is the thermal expansion coefficient between the substrate and the layer And the modulus of elasticity, the test shows that when the thermal expansion coefficient of the matrix is ​​greater than that of the use layer, a tensile stress is formed in the matrix, and the tensile stress produces cracks at the vertical interface on the matrix, and the residual tensile stress on the surface of the matrix is ​​unfavorable to the material properties; when the use layer When the coefficient of thermal expansion is greater than that of the matrix, the residual compressive stress will be formed in the matrix, which is beneficial to improve the physical and mechanical properties of the matrix, but if the difference in thermal expansion coefficient between the two is large, it will easily cause interface cracking, or cracks at the vertical interface in the use layer

In addition, because the elastic modulus of the matrix and the use layer are different, the layer with a larger elastic modulus bears more load, which is also easy to cause uneven force and cause the use layer to fall off.

The second is that there is a combination defect between the use layer and the substrate: under normal circumstances, the substrate and the use layer have already formed a blank, so the two materials can only be combined by welding, bonding, mechanical clamping, spraying, etc. There must be a third type of substance at the interface, such as Cu solder, colloid, air, etc. , the cemented carbide layer of this kind of composite structure is easy to fall off, crack, and delaminate, and it cannot withstand large impact applications.

[0005] The patent No. is 98122105 x, and the title of invention is "(Ceramics—Cemented Carbide Composite Blade and Its Technology" patent document), which discloses a kind of cemented carbide as a substrate, and the use layer is a composite blade of non-metallic ceramics. It mainly uses the characteristics of high hardness, high wear resistance, high heat resistance and high chemical stability of non-metallic ceramics, supplemented by hot pressing sintering method to improve its fracture toughness and flexural strength, but in the literature Described cemented carbide matrix is ​​essentially a kind of cermet (TiC+Ni), but its use layer is not the cemented carbide material that adopts, so still there is the defect that the characteristic difference of matrix and use layer is big, although provided by this patent It is possible to obtain composite structure tool ceramics with a continuous interface, but this product is only suitable for the application field of non-metallic ceramic cutting tools in extremely small impact situations

[0006] Although the matrix provided above achieves the purpose of saving W and Co resources, the interface of the composite structure product formed by it is a discontinuous transition, or the interface of the composite structure product formed is a continuous transition, but the obtained composite structure product can only withstand extreme conditions. Tool ceramics used in small impact applications cannot meet the same requirements as conventional single-layer cemented carbide with wide application and good comprehensive performance.