基于脉冲涡流热成像的面内方向性热扩散率测量

针对导电材料面内方向性热扩散率的测量,提出脉冲涡流热成像法这一新方法。该方法采用感应式脉冲线激励源,在导电试件表面形成沿一定方向的感应涡流,实现局部热激励,在非稳态条件下实现了材料面内方向热扩散率的测量;简单调节试件与线感应激励线圈的角度,就可以快速无损非接触地测量试件在垂直线圈方向上的热扩散率值。对感应线激励下面内热传导及高斯温度分布进行了分析,分别对AISI304不锈钢、纯铁、纯镍3种材料的热扩散率进行了测量,测量结果与手册值相符,偏差小于9.0%,相对扩展不确定度分别为3.18%,3.72%,3.70%。

Measurement of In-plane Directional Thermal Diffusivity Using Pulsed Eddy Current Thermography

To measure the in-plane directional thermal diffusivity of the conductive material, a new method called pulsed eddy current thermography is proposed. Eddy current along a certain direction is induced on the surface of the conductive material by using an inductive pulsed line excitation to achieve local heating. Under non-steady conditions, simply changing the relative position between the sample and the coil can quickly and non-destructively measure the diffusivity in the vertical direction of the coil. The in-plane heat conduction and the Gaussian temperature distribution are analyzed on the condition of the inductive pulsed line excitation. The AISI304 stainless steel, pure iron, and pure nickel are measured and the measurement results are in accordance with the literature values, all the deviations are less than 9.0% and the relative extended uncertainty is 3.18%,3.72% and 3.70% respectively.