METHOD OF ANALYZING/EVALUATING COEFFICIENT OF LINEAR EXPANSION OF EXTREMELY LOW EXPANSION GLASS MATERIAL, METHOD OF CALIBRATING LEAKAGE ELASTIC WAVE CHARACTERISTIC, ANALYTICAL EVALUATION METHOD USING LEAKAGE ELASTIC WAVE CHARACTERISTIC, AND METHOD OF MEASURING LEAKAGE ELASTIC WAVE CHARACTERISTIC

摘要

PROBLEM TO BE SOLVED: To analyze/evaluate a coefficient of linear expansion of an extremely low expansion glass material by an ultrasonic material characteristic analyzer. SOLUTION: A fundamental acoustic characteristic is made clear by measuring a sonic velocity of a bulk wave (longitudinal wave and transverse wave), frequency dependence of an attenuation coefficient and density, in the extremely low expansion glass material, and a standard sample is prepared to calibrate a device. Absolute values of velocities in both an LSAW and an LSSCW are found by an absolute calibration method using the standard sample. A bulk wave sonic velocity, an elastic modulus, a Young's modulus, and a Poisson's ratio are found on the basis of the values. A relation between the acoustic characteristic and the coefficient of linear expansion is found further, and the coefficient of linear expansion is evaluated on the basis of the acoustic characteristic. Relations to a chemical composition, a refractive index, a density and the like are also found to recognize changes thereof as changes of the sonic velocity. When a characteristic distribution due to a periodic striae exists, an accurate acoustic characteristic distribution in a substrate is grasped to conduct evaluation by selecting a cutout angle for the substrate with respect to a striae face. COPYRIGHT: (C)2006,JPO&NCIPI