Development of a System for Measuring Thermal Diffusivity of Thin Films by Laser Flash Method Based on a New Principle.

基于新原理的激光闪光法测量薄膜热扩散率系统的开发。

• 批准号: 01850145
• 负责人: WASEDA Yoshio
• 金额: $ 2.82万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B).
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01850145/
• 关键词: Thermal Diffusivity; Thermal Conductivity; Lase-Flash Method; Molten Salts; Ferrites; High Temperature Melts; 光外線検出器

A laser flash method for measuring thermal diffusivity in the direction parallel or perpendicular to the sample surface of film has been developed. On measurement of parallel direction of a sample, a pulsed laser beam which has narrow line-shaped cross section is flashed onto the front surface of the sample. The temperature response at the back surface at a certain distance away fro the line-shaped illuminated area of a laser beam is measured by the infrared detector and the thermal diffusivity value can be dete mined by comparing measured temperature response curve with theoretical one. On the other hand, the measurement of thermal diffusivity in the direction perpendicular to the sample surface of a film, a pulsed laser beam whose diameter is about 10 mm, is flashed onto the front surface of the sample. The temperature response at the back surface is measured by the infrared detector. The thermal diffusivity value can be determined by comparing with the theoretical solution including … More a pulse duration. The usefulness the present method has been demonstrated by measuring successfully thermal diffusivities of metallic foil samples of platinum (25 mum copper (18 mum), SUS304 stainles s steel (50 mum) and nickel (130 mum).Ruby lasers usually employed in the laser flash method for measuring thermal diffusivity of various inorganic substances a known to have the inhomogeneous energy distribution and their particular spatial intensity structure significantly effects the quantitative accuracy of the resultant thermal diffusivity data in some cases. Random packed fiber bundle made of plastic optical fiber wi plastic optical guiding rod has been developed for homogenizing the energy distribution in a laser beam on the specimen surface. T usefulness of this new device has been well approved by measuring the energy distribution and the thermal diffusivity of nickel disc.A simple cell and easy data processing have been proposed for measuring the thermal diffusivity of a liquid sample at high temperatures using the laser flash method. A cell consists of a liquid sample sandwiched by two metallic plates. The front surface one metallic plate is exposed to a single pulse of beam laser and the resulting temperature rise of the back surface of the other metal plate is measured. The logarithmic analysis proposed by James using the initial time region of the temperature response curve of a two layered cell system has been extended to apply to the present three layered cell system in order to estimate the thermal diffusivity value of a liquid sample. Measurements of distilled water and methanol were made first and the results were found to be in good agreement with the reference data. Then, the thermal diffusivities of molten NaNO_3 at 593-660 K and of molten KNO_3 at 621-694 were determined and the results also appear to agree reasonably well with those reported in the literature. Less

提出了一种测量平行或垂直于薄膜样品表面方向热扩散率的激光闪光法。在测量样品的平行方向时，将具有窄线状截面的脉冲激光照射到样品的前表面上。用红外探测器测量了在距激光线状照明区一定距离的背表面的温度响应，并将测量的温度响应曲线与理论温度响应曲线进行比较，确定了热扩散率的值。另一方面，在垂直于样品表面的方向上测量热扩散率时，将直径约为10 mm的脉冲激光照射到样品的前表面。背表面的温度响应由红外探测器测量。通过与包括…在内的理论解进行比较，可以确定热扩散系数的值更多的是脉冲持续时间。通过成功地测量了铂(25微米铜(18微米)、SUS304不锈钢(50微米)和镍(130微米)金属箔样品的热扩散率，证明了本方法的有效性。红宝石激光通常用于激光闪光法测量各种无机物的热扩散率，已知这些无机物具有不均匀的能量分布及其特殊的空间强度结构，在某些情况下显著影响所得到的热扩散率数据的定量精度。用塑料光纤和塑料导光棒制成的随机填充光纤束，用于均匀激光在试件表面的能量分布。通过测量镍片的能量分布和热扩散率，验证了该装置的有效性。提出了一种用激光闪光法测量高温下液体样品热扩散率的简易装置和易于数据处理的方法。电池由夹着两块金属板的液体样品组成。将一块金属板的前表面暴露在单脉冲光束激光下，并测量另一块金属板的后表面的温升。James提出的利用双层电池系统温度响应曲线的初始时间域的对数分析已扩展到适用于目前的三层电池系统，以估计液体样品的热扩散率。首次对蒸馏水和甲醇进行了测定，结果与参考数据吻合较好。在此基础上，测定了593-660 K熔融NaNO_3和621-694 K熔融KNO_3的热扩散率，结果与文献报道的结果基本一致。较少

项目成果

太田 弘道,柴田 浩幸,小倉 岳,早稲田 嘉夫,渋谷 幸生,布施 正樹: "ランダム配向光ファイバ-束によるルビ-レ-ザ-のエネルギ-分布の均一化および熱拡散率測定への応用" 熱物性. 3. 102-105 (1989)

Hiromichi Ota、Hiroyuki Shibata、Gaku Ogura、Yoshio Waseda、Yukio Shibuya、Masaki Fuse：“使用随机取向光纤束的红宝石激光器的均匀能量分布及其在热扩散率测量中的应用”热物理性质.3.102-105（1989）

H. Ohta, H. Shibata, Y. Shibuya and M. Fuse: "Random packed optical fiber bundle for homogenizing the energy distribution in a laser beam on the specimen surface and its application to the thermal diffusivity measurements." Netsu Bussei. Vol. 3. 102-106 (

H. Ohta、H. Shibata、Y. Shibuya 和 M. Fuse：“用于均匀化样品表面激光束能量分布的随机封装光纤束及其在热扩散率测量中的应用。”

H. Ohta, G. Ogura, Y. Waseda and M. Suzuki: "Thermal diffusivity measurements of molten salts using a three-layered cell by the laser flash method." Rev. Sci. Instrum. Vol. 61. 2645-2649 (1990)

H. Ohta、G. Ogura、Y. Waseda 和 M. Suzuki：“通过激光闪光法使用三层池测量熔盐的热扩散率。”

G. Ogura, In-Kook Suh, Hiohta and Y. Waseda: "Thermal diffusivity measurements of boron oxide melts by laser flash method." J. Ceram. Soc. Japan, Inter. Ed.Vol. 98. 320-322 (1990)

G. Ogura、In-Kook Suh、Hiohta 和 Y. Waseda：“通过激光闪光法测量氧化硼熔体的热扩散率。”

Gaku Ogura,InーKook Suh,Hiromichi Ohta,Yoshio Waseda: "Thermal diffusivity measurements of boron oxide melts by laser flash method" J.Ceram.Soc.Japan,Inter.Ed.98. 320-322 (1990)

Gaku Ogura、In-Kook Suh、Hiromichi Ohta、Yoshio Waseda：“通过激光闪光法测量氧化硼熔体的热扩散率”J.Ceram.Soc.Japan，Inter.Ed.98 (1990)。