Method and device for measuring thermal diffusivity of materials by transient fluorescence

Abstract

The invention provides a method and an apparatus for measuring thermal diffusivity of materials through transient fluorescence. The method includes the steps of: (1) irradiating the surface of a sample by means of modulating pulse laser as a heating light source for the sample and an excitation light source for a fluorescence signal; (2) collecting the fed-back fluorescence signal when the sample is excited, and comparing the signal intensity with a fluorescence intensity-temperature curve of the sample, thus obtaining temperature information of the sample; (3) changing the pulse width of the pulse laser for several times to obtain transient temperature increase of the sample in different transient heating periods; and (4) according to an analytic solution expression of temperature field of a heat conduction model of the to-be-tested sample, substituting several groups of test data and performing fitting to obtain the thermal diffusivity of the material. On the basis of the method, a measurement apparatus platform is correspondingly designed. The method is not liable to cause sample damage, has low measurement error and is high in efficiency during the measurement of the thermal diffusivity of materials.

Description

technical field [0001] The invention belongs to the technical field of transient optical measurement of thermal physical properties of materials, and in particular relates to a method and a measurement device for measuring thermal diffusivity of materials by using transient fluorescence. Background technique [0002] The thermal diffusivity of a material is an index to evaluate the internal heat diffusion ability of an object, a very important thermophysical performance parameter of a substance, and an indispensable key parameter for adiabatic design and analysis and calculation. The measurement method of thermal diffusivity is generally an unsteady method, which can also be called a transient method or a dynamic method. The starting point is the unsteady heat conduction differential equation. The measurement principle is to apply thermal disturbance to the sample, measure the response of the sample to the thermal disturbance at the same time, and then determine the thermop...

AI Technical Summary

Problems solved by technology

In the contact measurement method, the sample is generally heated electrically, and the temperature is measured through the temperature dependence of the resistance, such as the hot wire method and the thermal probe method. (2) There is contact resistance, which causes inevitable errors to the experiment

In order to solve the existing problems of sample damage, large error and low efficiency in the existing transient measurement method of thermal diffusivity

Images