Research On Testing Technology Of Thermal Physical Properties Of Materials Based On Transient Flash Method

In the study of thermo physical properties,the study of thermo physical properties testing methods and techniques is of great significance.The research on thermo physical properties of materials is closely related to space technology,energy technology,materials science,information technology,and micro-electro-mechanical systems.The importance of research on thermo physical properties of materials is usually proportional to the level of industrial and scientific and technological development.of.Due to the emergence of many new materials with uni que properties,the research on thermo physical properties is becoming more and more tightly integrated with new materials.The research on test methods has been changed from the previous steady state to the transient method for the study of thermo physical properties under abnormal conditions.The stage of the Lord.In this paper,the development and current status of thermo physical properties testing methods and techniques are introduced.The principle of transient flashing method is elaborated in detail,and the correction method of transient flashing method is explained and compared.Since the transient flash method is based on the Parker theoretical formula based on one-dimensional unsteady heat conduction,there are many ideal assumptions.However,in the actual experimental process,the ideal assumptions are difficult to meet,which leads to errors in the test due to deviation from the assumptions,thus limiting the measurement accuracy of the thermo physical properties of the material.The purpose of this paper is to develop a thermo physical property measuring device based on transient flash method.The hardware design is designed to meet its ideal experimental conditions,and the radiant heat loss effect,finite pulse time effect and non-uniformity affecting the accuracy of the results.Theoretical calculations are corrected for factors such as heating effects to obtain reliable thermo physical property data.In this paper,the basic principle of flash method is analyzed,and the method of modifying the influence factor of flash method is determined.A device for measuring thermal properties of materials is developed,and a software system with various modification methods is developed.The main tasks are as follows :1.A device for measuring thermal properties of materials using Nd-glass laser as pulse heating source,weak signal amplification system and high-speed data acquisition equipment has been developed.It is a new experimental device for measuring thermal diffusivity,specific heat and thermal conductivity simultaneously.2.A data processing software with correction of radiation heat loss effect,finite pulse time effect and non-uniform heating effect is developed.3.The new device was used to compare the standard sample,and the appropriate thermocouple was selected as the temperature sensor and the response was corrected.The results showed that the difference between the thermal diffusivity of the new device and the standard reference value was less than 3%.