Low-temperature material linear expansion coefficient measuring method and low-temperature material linear expansion coefficient measuring device

Abstract

The invention discloses a low-temperature material linear expansion coefficient measuring method and a low-temperature material linear expansion coefficient measuring device, and relates to the field of material thermal physical performance test and characterizing. The method achieves that liquid nitrogen temperature is kept within a temperature range of 300K through a dedicated variable temperature dewar; in terms of control of the temperature on a stacked bilayer structure sample composed of standard material and material to be measured, coordinate scanning is performed on the surface of a bilayer structure below each temperature point by utilization of a three-dimensional coordinate measuring system to obtain a maximum deflection deformation value at the center position of a bilayer structure on the position of a temperature point needing to be measured; and the deflection theory computation formula of bimetallic effect is combined to derive a linear expansion coefficient of the material to be measured when the material to be measured is at a corresponding temperature according to standard known material parameters. The low-temperature material linear expansion coefficient measuring method and the low-temperature material linear expansion coefficient measuring device are simple in principle, easy in sample preparation, visualized in measuring amounts, favored in measuring, not trivial in measuring device set-up, and strong in operability and practicability.

Description

technical field [0001] The invention relates to the field of characterization of thermal physical properties of materials, specifically a method and a device for measuring the linear expansion coefficient of solid materials in the range from room temperature (300K) to liquid nitrogen temperature (77K). Background technique [0002] The methods for measuring the thermal expansion coefficient of materials mainly include mechanical, optical and electrical measurement methods such as ejector method, optical interference method, capacitance method and resistance measurement method. Usually these methods are carried out at room temperature, and it is difficult to obtain the low temperature parameters of the material. In the field of low temperature applications, due to the difficulty of testing and other reasons, there are fewer corresponding testing methods and data. Therefore, for specific materials in special application fields, it is very important to accurately test the therm...

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In addition, due to differences in the source of materials and the manufacturing process of products in different manufacturing plants

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