Material Thermal Parameters Of The Photoacoustic Piezoelectric Detection And Realization

Based on a simplified thermo-elastic theory, the photo-acoustic piezoelectric (PAPE) technique has been employed to measure the thermal diffusivities of materials easily and effectively. The corresponding experimental researches on measuring the thermal diffusivities of metal, alloy and composite have been carried out. According to the analysis of the PAPE theory, the different thermal diffusivities have different errors in experiment and the available range of the thermal diffusivity was obtained. In order to decrease the experimental errors, an automatic experimental system has been built.1. The PAPE theory of measuring the thermal diffusivity has been introduced and the corresponding experimental system has been set up, which was testified by the standard samples, such as copper, brass and aluminum. Using this experimental system, the effective thermal diffusivities of monolithic matrix alloy and Mullite/Al-Cu-Mg composite have been investigated.2. According to the PAPE theory, the different thermal diffusivities have different measurement accuracy, which has been testified by corresponding experiments. Finally, the optimum test range of the thermal diffusivity has been investigated.3. The principle of LabVIEW technique has been introduced. Based on this technique, the serial ports communications of the function generator and lock-in amplifier with the computer have been studied. The automatic testing system has been set up, which can decrease the errors of manual experimental operation.By the research of PAPE technique in this dissertation, it shows that: the PAPE technique can be applied to measure the thermal diffusivities of the samples such as metal, alloy and short fibre reinforced composite, of which the values are more than 10mm2/s as well.