Photothermal Mirror Method for the Study of Thermal Diffusivity and Thermo-Elastic Properties of Opaque Solid Materials
Photothermal Mirror Method for the Study of Thermal Diffusivity and Thermo-Elastic Properties of Opaque Solid Materials
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光热镜法研究不透明固体材料的热扩散率和热弹性性能
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Bizenuh Workie
中科院分区：
文献类型：
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作者：
A. Marcano;G. Gwanmesia;Bizenuh Workie
对激光聚焦在一组固体样品表面产生的光热镜面信号的时间演化和幅度进行了理论和实验研究。基于同时求解热扩散率方程和热弹性变形方程的理论模型，计算了信号的瞬时时间演化和幅度。我们观察到玻璃、石英、金属和合成陶瓷氧化物等不同样品的同一时间演化模式。数据表明，热镜的建立时间与所有样品的热扩散率的倒数之间存在线性关系。对于中等功率水平，我们还观察到信号的稳定值和热致相移值之间的线性行为。根据标定曲线，我们确定了两种可能的核反应堆控制棒材料的热诱导相和热扩散系数。钛酸镝(Hbox{Dy}_{2})和二钛酸镝($HBox{Dy}_{2}\Hbox{Dy}_{2}\Hbox{O}_{7}$$Dy2Ti2O7)分别为$$D=(7.0\pm 0.4)\10^{-7}\m{m^{2}\cdot S^{-1}}$D=(7.0±0.4)×10-7m2·S-1。
We have carried out the theoretical and experimental time evolution and amplitude study of the photothermal mirror signal generated by focusing a laser beam on the surface of a suite of solid samples. Based on a theoretical model that resolves the thermal diffusivity equation and the equation for thermo-elastic deformations simultaneously, we have calculated the transient time evolution and amplitude of the signal. We observe the same time evolution pattern for samples as diverse as glass, quartz, metals, and synthetic ceramic oxides. The data have yielded a linear dependence between the time build-up of the thermal mirror and the inverse of the thermal diffusivity for all the samples. For moderate power levels, we also observe a linear behavior between the stationary value of the signal and the thermally induced phase shift value. From the calibration curves, we have determined the thermally induced phase and the thermal diffusivity coefficients of two prospective nuclear reactor control rod materials, dysprosium titanate ($$\hbox {Dy}_{2}\hbox {TiO}_{5}$$Dy2TiO5) and dysprosium dititanate ($$\hbox {Dy}_{2}\hbox {Ti}_{2}\hbox {O}_{7}$$Dy2Ti2O7) to be $$D = (7.0 \pm 0.4) \times 10^{-7} \mathrm{m^{2}\cdot s^{-1}}$$D=(7.0±0.4)×10-7m2·s-1.