Silicon nitride based nano complex gradient function ceramic tool material and preparation thereof

Abstract

The invention provides a silicon nitride-based nano composite functionally gradient ceramic cutter material and a preparation method thereof. The ceramic cutter material is provided with a five-layer symmetrical gradient level structure; the component contents of the symmetrical layers relative to a central layer are the same and the thickness of each layer is consistent; the components of each layer are all micron Si3N4, nano Si3N4, nano TiC, nano TiN, Al2O3 and Y2O3. The preparation method thereof is as follows: (1) preparing materials according to the content of each component in each layer; (2) dispersing the nano materials in each layer; (3) mixing the other materials in each layer with the dispersed nano materials to obtain the powder material of a composite ceramic material which disperses excellently; and (4) employing a powder layering paving method and a hot pressing sintering technique to carry out loading and sintering. The invention improves the anti-bending intensity and the fracture toughness property of the materials, and improves the fracture toughness property of the materials; while the gradients of the nano TiC and the nano TiN are arranged in layers, thus leading the mechanical property of the cutter material to be changed in stagewise gradient, and being capable of effectively easing the residual heat stress.

Description

technical field [0001] The invention relates to a silicon nitride-based nanocomposite gradient functional ceramic cutting tool material and a preparation method thereof, belonging to the technical field of cutting tool materials. Background technique [0002] Due to its excellent properties such as high hardness, high wear resistance, high heat resistance and high chemical stability, ceramic tool materials are comparable to cemented carbide tools including coated tools in the field of high-speed cutting and cutting difficult-to-machine materials. has obvious advantages over. However, silicon nitride-based ceramic tool materials also have their own weaknesses, such as low strength and toughness, high thermal expansion coefficient, poor thermal conductivity and thermal shock resistance, which limit its application range. [0003] At present, a lot of research has been carried out at home and abroad, and the mechanical properties of ceramic materials are improved by optimizing...

AI Technical Summary

Problems solved by technology

[0006] The present invention aims at the problem that the existing silicon nitride-based nanocomposite gradient functional ceramic materials have significantly improved strength but not obvious toughness, and provides a silicon nitride with high strength, high toughness and high thermal shock resistance, which is suitable for high-speed processing Nano-based composite gradient functional ceramic cutting tool material, and a preparation method of the material is provided at the same time