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a kind of si 3 no 4 Gradient material and its preparation method

A gradient material and purity technology, applied in the field of Si3N4 gradient material and its preparation, can solve the problems of detachment of the surface layer from the core, weak binding force, weakening the application of gradient materials, etc., and achieve the effect of simple process and low cost.

Active Publication Date: 2020-08-11
吉林长玉特陶新材料技术股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Currently, Si 3 N 4 The preparation of gradient materials is mainly through the sintering of raw materials and even materials with very different compositions, so that the surface layer and hardness have different properties; but due to the differences in composition and structure between the surface layer and the core material, the combination of the two The force is weak, and some even appear to separate the surface layer from the core during the sintering process, which greatly weakens the Si 3 N 4 Application of Gradient Materials

Method used

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  • a kind of si <sub>3</sub> no <sub>4</sub> Gradient material and its preparation method
  • a kind of si <sub>3</sub> no <sub>4</sub> Gradient material and its preparation method
  • a kind of si <sub>3</sub> no <sub>4</sub> Gradient material and its preparation method

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preparation example Construction

[0032] The invention provides a Si 3 N 4 The preparation method of gradient material comprises the following steps:

[0033] a) Provide mixed powder A and mixed powder B;

[0034] The mixed powder A includes Si powder, TiO 2 Powder and sintering aid, wherein the sintering aid consists of Al in a molar ratio of 1 or less 2 o 3 and Re 2 o 3 Composition; the mixed powder B includes Si, TiO 2 and a sintering aid, wherein the sintering aid consists of Al with a molar ratio greater than 1 2 o 3 and Re 2o 3 composition;

[0035] The Re is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu;

[0036] b) laying the mixed powder A and the mixed powder B alternately to form a multi-layer structure, and press molding to obtain a green body;

[0037] c) sintering the green body obtained in step b) after nitriding to obtain Si 3 N 4 gradient material.

[0038] The present invention firstly provides mixed powder A and mixed powder B. In the pres...

Embodiment 1

[0056] (1) Mixed powder A formula: Si: TiO 2 The mass fraction ratio is 95%: 5%, control Si 3 N 4 : The molar ratio of sintering aids is 93%: 7% ingredients, of which, Si 3 N 4 The calculation is based on the complete nitriding of Si powder; the sintering aid is composed of Al with a molar ratio of 1:1 2 o 3 and Y 2 o 3 composition;

[0057] Mixed powder B formula: Si: TiO 2 The mass fraction ratio is 95%: 5%, control Si 3 N 4 : The molar ratio of sintering aids is 93%: 7% ingredients, of which, Si 3 N 4 Calculated according to the complete nitriding of Si powder; the sintering aid is composed of Al with a molar ratio of 2.5:1 2 o 3 and Y 2 o 3 composition;

[0058] Si powder and TiO 2 Powder as raw material, with Al 2 o 3 Powder and Y 2 o 3 Powder is a sintering aid, and Si powder, TiO 2 powder and sintering aids, with ethanol as solvent and Si 3 N 4 The ball is a ball milling medium, mixed on a planetary ball mill for 8 hours, and dried to obtain Si-T...

Embodiment 2

[0066] (1) Mixed powder A formula: Si: TiO 2 The mass fraction ratio is 90%: 10%, control Si 3 N 4 : The molar ratio of sintering aids is 90%: 10% ingredients, wherein, Si 3 N 4 The calculation is based on the complete nitriding of Si powder; the sintering aid is composed of Al with a molar ratio of 1:1 2 o 3 and Yb 2 o 3 composition;

[0067] Mixed powder B formula: Si: TiO 2 The mass fraction ratio is 90%: 10%, control Si 3 N 4 : The molar ratio of sintering aids is 90%: 10% ingredients, wherein, Si 3 N 4 Calculated according to the complete nitriding of Si powder; the sintering aid is composed of Al with a molar ratio of 3:1 2 o 3 and Yb 2 o 3 composition;

[0068] Si powder and TiO 2 Powder as raw material, with Al 2 o 3 Powder and Yb 2 o 3 Powder is a sintering aid, and Si powder, TiO 2 powder and sintering aids, with ethanol as solvent and Si 3 N 4 The ball is a ball milling medium, mixed on a planetary ball mill for 8 hours, and dried to obtain S...

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Abstract

A method for preparing a Si3N4 gradient material is provided, comprising steps of: a) providing a mixed powder A and a mixed powder B, and the mixed powder A comprises a Si powder, a TiO2 powder and a sintering aid, and the sintering aid is composed of Al2O3 and Re2O3 in a molar ratio of less than or equal to 1, and the mixed powder B comprises Si, TiO2 and a sintering aid, and the sintering aid is composed of Al2O3 and Re2O3 in a molar ratio greater than 1. Re is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu; b) alternatively paving the mixed powder A and the mixed powder B to form a multilayer structure, and press-forming to obtain a body; c) nitriding the body obtained in step b) and sintering to obtain a Si3N4 gradient material. The method allows control of a β-silicon nitride / α-silicon nitride in a nitriding stage by means of controlling the ratio of Al2O3 to Re2O3 in a sintering aid. The obtained Si3N4 gradient material has a strong bonding strength between gradient layers, excellent mechanical properties with surface hardness and core toughness. A Si3N4 gradient material prepared by the method is also provided.

Description

technical field [0001] The present invention relates to Si 3 N 4 The technical field of ceramic materials, more specifically, relates to a Si 3 N 4 Gradient material and its preparation method. Background technique [0002] Si 3 N 4 As a structural material, ceramic materials have excellent mechanical properties, such as high hardness, high strength, wear resistance, high temperature resistance, etc., and can be widely used in bearings, high-speed cutting tools, armor, etc.; but in extremely high temperature and high-speed cutting It is still easy to wear under harsh conditions such as Si 3 N 4 Ceramic materials can usually be used to prepare gradient materials or use PVD and CVD techniques to further improve their performance. [0003] For PVD and CVD technologies, there is often the defect that the coating is too thin and the protective effect is not good; moreover, PVD and CVD technologies also have the problem of insufficient bonding between the substrate and the...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/591C04B35/622C04B35/64
CPCC04B35/591C04B35/622C04B35/64C04B2235/3232C04B2235/658C04B2235/75C04B2235/77C04B2235/96
Inventor 郭伟明吴利翔牛文彬林华泰
Owner 吉林长玉特陶新材料技术股份有限公司