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A method for preparing dense and super large negative thermal expansion bulk material

A negative thermal expansion material and negative thermal expansion technology, applied in the field of negative thermal expansion materials, can solve the problems of no reports and high density, and achieve the effects of high density, simple preparation process and strong operability

Active Publication Date: 2021-04-13
SHANGHAI JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, there are many domestic studies on anti-perovskite structure negative thermal expansion materials. However, Ge, Ga, and other noble metal elements are widely used in the negative thermal expansion materials studied. The absolute value of the negative thermal expansion coefficient is less than 100ppm / K, and the temperature range of negative thermal expansion is concentrated. In the range of low temperature or even polar temperature conditions, and in the widely used temperature range of room temperature and above, the research on negative thermal expansion materials with super large negative expansion coefficient and high density has not been reported

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  • A method for preparing dense and super large negative thermal expansion bulk material
  • A method for preparing dense and super large negative thermal expansion bulk material
  • A method for preparing dense and super large negative thermal expansion bulk material

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Embodiment 1

[0032] This embodiment includes the following steps:

[0033] 1) Mn 2 Preparation of N: Manganese powder is sintered in a high-purity nitrogen (99.999%) atmosphere with a purity of 99.9% and a particle size of 75 μm to prepare Mn 2 N, the sintering temperature is 550°C, the holding time is 20h, after removing the green MnO on the surface, the Mn 2 N ball milling to a particle size of 2 μm, set aside;

[0034] 2) Mn 4 Preparation of N: Manganese powder is sintered in a high-purity nitrogen (99.999%) atmosphere with a purity of 99.9% and a particle size of 75 μm to prepare Mn 2 N. The sintering temperature is 500°C, and the holding time is 20h. After removing the surface green MnO, the Mn 4 N ball milling to a particle size of 2 μm, set aside;

[0035] 3) Mn 3 Preparation of ZnN: Mn 2 N and zinc powder (purity 99.99%, particle size 25μm) are mixed at the ratio of atomic ratio Mn:Zn=3:1, and Mn is prepared in high-purity nitrogen (purity 99.999%) 3 ZnN; the sintering te...

Embodiment 2

[0040] This embodiment includes the following steps:

[0041] 1) Mn 2 Preparation of N: Manganese powder is sintered in a high-purity nitrogen (99.999%) atmosphere with a purity of 99.9% and a particle size of 75 μm to prepare Mn 2 N. The sintering temperature is 750°C, and the holding time is 20-50h. After removing the surface green MnO, the Mn 2 N ball milling to a particle size of 20 μm, set aside;

[0042] 2) Mn 4 Preparation of N: Manganese powder is sintered in a high-purity nitrogen (99.999%) atmosphere with a purity of 99.9% and a particle size of 75 μm to prepare Mn 2 N. The sintering temperature is 800°C, and the holding time is 40h. After removing the surface green MnO, the Mn 4 N ball milling to a particle size of 20 μm, set aside;

[0043] 3) Mn 3 Preparation of ZnN: Mn 2 N and zinc powder (purity 99.99%, particle size 25μm) are mixed at the ratio of atomic ratio Mn:Zn=3:1, and Mn is prepared in high-purity nitrogen (purity 99.999%) 3 ZnN; the sinterin...

Embodiment 3

[0048] This embodiment includes the following steps:

[0049] 1) Mn 2 Preparation of N: Manganese powder is sintered in a high-purity nitrogen (99.999%) atmosphere with a purity of 99.9% and a particle size of 75 μm to prepare Mn 2 N. The sintering temperature is 600°C, and the holding time is 45h. After removing the surface green MnO, the Mn 2 N ball milling to a particle size of 15 μm, set aside;

[0050] 2) Mn 4 Preparation of N: Manganese powder is sintered in a high-purity nitrogen (99.999%) atmosphere with a purity of 99.9% and a particle size of 75 μm to prepare Mn 2 N. The sintering temperature is 700°C, and the holding time is 35h. After removing the surface green MnO, the Mn 4 N ball milling to a particle size of 15 μm, set aside;

[0051] 3) Mn 3 Preparation of ZnN: Mn 2 N and zinc powder (purity 99.99%, particle size 25μm) are mixed at the ratio of atomic ratio Mn:Zn=3:1, and Mn is prepared in high-purity nitrogen (purity 99.999%) 3 ZnN; the sintering t...

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Abstract

The invention provides a method for preparing a compact super large negative thermal expansion block material, first preparing a precursor powder: Mn 4 N, Mn 3 ZnN and Mn 3 SnN, Mn 4 N, Mn 3 ZnN and Mn 3 SnN is mixed and pressed into discs. Then, high temperature sintering is used to prepare negative thermal expansion materials, and the disk is sealed in a vacuum quartz glass tube for sintering to obtain Mn 3 (Mn x Zn y sn z ) N. Will Mn 3 (Mn x Zn y sn z )N is crushed into powder, placed in a graphite mold, placed in a discharge plasma furnace for sintering, and taken out after cooling. The present invention can prepare dense negative expansion bulk material Mn 3 (Mn x Zn y sn z )N, the preparation process is simple, the operability is strong, the density of the material is high, and the absolute value of the negative thermal expansion coefficient can reach up to 100ppm / K.

Description

technical field [0001] The invention relates to a material with negative thermal expansion, in particular to a method for preparing dense super large negative thermal expansion bulk material Mn 3 (Mn x Zn y sn z )N method. Background technique [0002] Negative thermal expansion material has been widely concerned in the world since the 20th century, and it is a special new functional material. The main use of negative thermal expansion materials is as a regulator of thermal expansion, which is used to change the thermal expansion coefficient of traditional materials, which is of great significance to aerospace, electronic components, optical devices, precision instruments and other fields. Many negative thermal expansion materials cannot adjust the thermal expansion properties of materials because the absolute value of the negative expansion coefficient is not large enough. Therefore, searching for ultra-large negative thermal expansion materials has become a hotspot in...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/58C04B35/622C04B35/64
CPCC04B35/58C04B35/622C04B35/64C04B2235/3852C04B2235/666C04B2235/77
Inventor 曹贺欧阳求保
Owner SHANGHAI JIAOTONG UNIV