A material with adjustable negative thermal expansion coefficient and its preparation method and application

Abstract

The invention provides a material with adjustable negative thermal expansion coefficient and its preparation method and application. The material is a MnCoGe-based and MnNiGe-based alloy. The material is introduced by high-energy ball milling to realize residual stress and defects, and at the same time control the particle size of the material 0.3 to 200 μm. The invention introduces residual stress and different degrees of structural defects through high-energy ball milling, while controlling particle size, and can realize continuously adjustable negative thermal expansion behavior and ultra-low thermal expansion in MnCoGe-based or MnNiGe-based alloy single metal materials. The thermal conductivity, electrical conductivity, and mechanical properties of the bonded particle molding material of the present invention can be greatly adjusted by selecting parameters such as binders with different characteristics and molding processes, so the material of the present invention is suitable for the preparation of high-precision optical instruments and low temperature coefficient mechanical parts. Has important practical value.

Description

Technical field [0001] The invention relates to a material capable of adjusting negative thermal expansion coefficient and realizing ultra-low thermal expansion, and a preparation method and application thereof. Background technique [0002] The thermal expansion effect refers to the effect that the volume of an object changes with the change of temperature, and the thermal expansion coefficient is used to measure the magnitude of the volume change caused by the thermal expansion effect. Most solid materials have a positive thermal expansion effect, that is, as the temperature rises, the material expands; very few solid materials have a negative expansion effect. [0003] However, in practical applications, many high-precision optical instruments and mechanical parts with low temperature coefficients often require the use of materials with precise thermal expansion coefficients or even zero expansion coefficients. At present, the way people obtain materials with precise thermal ex...

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Problems solved by technology

Most of the negative thermal expansion coefficients of these new materials cannot be greatly adjusted, and the working temperature range is relatively narrow, and the mechanical, thermal and electrical properties also need to be improved.

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