Experimental Study for Evaluating Striae Structure of TiO2–SiO2 Glasses Using the Line-Focus-Beam Ultrasonic Material Characterization System
Experimental Study for Evaluating Striae Structure of TiO2–SiO2 Glasses Using the Line-Focus-Beam Ultrasonic Material Characterization System
复制标题
使用线聚焦束超声材料表征系统评估 TiO2-SiO2 玻璃条纹结构的实验研究
DOI：
10.1143/jjap.45.6445
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发表时间：
2006
影响因子：
1.5
通讯作者：
Kouji Suzuki
中科院分区：
文献类型：
--
作者：
Y. Ohashi;J. Kushibiki;M. Arakawa;Kouji Suzuki
利用线聚焦束（LFB）超声材料表征系统测量了TiO 2-SiO2超低膨胀玻璃中TiO 2浓度变化引起的条纹结构。用火焰水解法制备了一个大的圆板玻璃锭，在其表面上测量了LSAW的速度分布。随后的程序，包括抛光样品的表面，以减少样品厚度40微米，并测量表面上的LSAW速度分布重复五次，以检查至少一个周期的条纹。在玻璃锭的存款方向上和在其径向方向上清楚地观察到TiO 2浓度变化。在整个检查区域的最大LSAW速度差为11.7米/秒，对应于0.70重量%的TiO 2浓度。三维条纹结构显示，在检查区域中的条纹平面几乎平行于衬底表面，但在径向方向上轻轻地向下弯曲。该平面具有以约0.16 mm的条纹周期性和约440 mm的曲率半径层叠的略微凸起的横截面，并且还以曲率半径约450 mm的圆形形式存在。超声波方法将有助于改善与生产工艺条件相关的玻璃的特性和均匀性。
Striae configurations in TiO2–SiO2 ultra-low-expansion glasses caused by variations in TiO2 concentration were investigated through measurement of leaky surface acoustic wave (LSAW) velocities by the line-focus-beam (LFB) ultrasonic material characterization system. LSAW velocity distributions were measured on the surface of a specimen substrate prepared from a large circular plate glass ingot produced by the direct method using a flame hydrolysis process. A subsequent procedure that included polishing the surface of the specimen to reduce the specimen thickness by 40 µm and measuring the LSAW velocity distributions on the surface was repeated five times in order to examine at least one period of the striae. TiO2 concentration variations were clearly observed in the deposit direction of the glass ingot and in its radial direction. The maximum LSAW velocity difference over the whole examined region was 11.7 m/s, corresponding to 0.70 wt % TiO2 concentration. The three-dimensional striae structure revealed that the striae plane in the examined region was almost parallel to the substrate surface but gently curved down in the radial direction. The plane had a slightly convex-shaped cross section layered with a striae periodicity of about 0.16 mm and a curvature radius of about 440 mm, and also existed in a circular form with a curvature radius of about 450 mm. The ultrasonic method will contribute to improvement of characteristics and homogeneity of glass associated with production-process conditions.