Method and system based on laser point heat source to measure thermophysical parameters of solid material

Abstract

The invention relates to the technical field of testing of thermophysical parameters of materials, in particular to a method and system based on a laser point heat source to measure thermophysical parameters of a solid material. The system comprises a laser emitter, a vacuum box, a vacuum pump, a pressure meter and a data acquisition component; the pressure meter and the vacuum pump are mounted onthe lateral side of the vacuum box, the pressure meter includes a detection head and a meter head, the detection head is passed through the lateral side of the vacuum box into an inner cavity of thevacuum box, heat conductivity coefficient and heat diffusion rate of the solid material are measured via a parameter estimation method directly based on a constant-power boundary one-dimensional unsteady-state heat transfer model, and errors due to excessive simplification of a math model are avoided; in addition, for the case that estimation according to specific heat capacity parameters has lowsensitivity and has great errors, a strategy of estimating heat diffusion rate prior to correcting specific heat capacity estimated value is utilized, and heat conductivity coefficient, specific heatcapacity and heat diffusion rate of the material are accurately estimated at the same time.

Description

technical field [0001] The invention relates to the technical field of testing thermal physical parameters of materials, in particular to a method and system for measuring thermal physical parameters of solid materials based on a laser point heat source. Background technique [0002] In recent years, the use of laser beams to form fixed point heat sources or moving line heat sources to achieve high-precision welding of special workpieces has been widely used. , if the distance is relatively short (the irradiation distance is less than 0.5m), the loss of laser energy due to factors such as diffuse reflection, transmission in the air, and transmission is negligible, and a point heat source with a certain heating power will be formed, and it will be tested Heat transfer in components for which there is a well-defined mathematical model. [0003] Compared with solid-state electric heating heat sources such as heating plates, heating wires, and heating rods, lasers have better c...

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Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the present invention provides a method and system for measuring the thermophysical parameters of solid materials based on a laser point heat source, which is used to solve the strict requirements of the existing methods on the experimental conditions, such as the requirements on the surface flatness of the test piece by the laser flash method Otherwise, the surface area calculation error caused by the uneven surface of the sample will bring obvious effects on the conversion of laser heating power and other problems; the present invention is realized through the following technical solutions:

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