闪光法测定半透光物质热扩散率

针对传统的闪光法在物理模型上不适于用来测试半透光物质热扩散率的问题，提出了一个新的物理模型，该模型根据物质的透光性，确定样品对脉冲激光的吸收为指数型，建立了相应的微分方程并求得其解析解．在激光导热仪上对A1N、牛角2种试样进行了测试，采用正交拟合的方法计算了这2种试样的热扩散率．结果表明2个MN试样的热扩散率值分别为0．482和0．502cm

Thermal diffusivity measurement ofsemi-transparent materials with flash method

Aiming at the physical model inapplicability of flash method to measure thermal diffusivity of semi-transparentmaterials, a new physical model was proposed. In the model, according to the permeance of materials, the pulse laserabsorption of materials is of exponential type, and the authors establish a relevant differential equation and get a analyticalform. On the laser heat conductivity apparatus, thermal diffusivities of A1N and ox horn samples were measured and theresults were calculated with the orthogonal fitting method. The results show that the thermal diffusivity of two AIN samplesare 0.482 cm2 ·s-1 and 0.502 cm2·s-1 and the thermal diffusivity of two ox hom samples are 1.38 × 10-3 cm2·s-1 and1.40× 10-3 cm2·s-1 respectively. The theoretical fitting curves are in agreement with the experimental data quite well,which shows that the theoretical model is suitable and accords with the experiment. When the absorption is close to theinfinite, the model is transformed into Parker equation, which shows that this model is generally suitable, and the Parkerequation is only a special case of this model