Functionally-gradient ceramic knife tool with layer-by-layer nested structure and preparation method thereof

Abstract

The invention discloses a functionally-gradient ceramic knife tool with a layer-by-layer nested structure and a preparation method thereof. The functionally-gradient ceramic knife tool at least comprises three layers of composites including AlMgB14 and TiB2; the three layers of composites are distributed layer by layer from inside to outside, and the mass ratios of the two materials in each layer are different; the content of the AlMgB14 is gradually increased from a core part layer to a surface layer; the content of the AlMgB14 is the lowest at the core part layers and the highest at the surface layers of a front knife surface, a main rear knife surface and an auxiliary rear knife surface of the ceramic knife tool. In the preparation method, at least three types of composite powder with different mass ratios of the AlMgB14 and the TiB2 are prepared; each type of composite powder is vacuum-dried and screened, then spread and pre-pressed in a graphite mould layer by layer from inside to outside according to the content of the AlMgB14 from low to high, and is finally sintered in a vacuum hot-pressing manner. As the layer-by-layer nested structure is adopted in the invention, mechanical performance indexes of the ceramic knife tool are increased and the service life of the ceramic knife tool is prolonged by 20 to 30% than that of the functionally-gradient ceramic knife tool with a traditional structure.

Description

technical field [0001] The invention relates to a gradient functional ceramic cutter and a preparation method thereof, belonging to the technical field of ceramic cutter materials. Background technique [0002] AlMgB 14 It is a new type of superhard wear-resistant boride, which has the characteristics of high hardness and low friction coefficient. The ceramic cutting tools prepared with it as the substrate have the advantages of high hardness, wear resistance, heat resistance and chemical stability, and are more suitable for It is suitable for processing titanium alloys, but its own brittleness limits its application range, and its strength is also low. Researchers and cutting tool manufacturers at home and abroad generally use AlMgB 14 The method of adding toughening and strengthening phases to the matrix improves its mechanical properties, such as adding AlN, TiC, TiB 2 etc., where adding TiB 2 The toughening and reinforcing effect is the best. However, the effects of...

AI Technical Summary

Problems solved by technology

However, the current gradient functional ceramic tools such as figure 1 As shown, it is a sandwich structure, with three or more layers stacked together. This structure has the following disadvantages: when cutting, the tool tip only has a gradient function structure downward along the rake face, while the main flank face And the auxiliary flank facing the core of the tool does not have a gradient function structure, so that the tool tip composed of the rake face, the main flank face and the auxiliary flank face is still prone to chipping

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