| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively and simply evaluate the characteristics of a ceramics material by arranging an ultrasonic vibrator having input and output lines on the surface of the ceramics material to measure the attenuation state in the material. SOLUTION: The attenuation state of ultrasonic pulses in a ceramics material is measured by measuring machinery such as oscilloscope. As ultrasonic pulses, pulse waves of MHz-several GHz are usually used. A lithium niobate membrane having a gold electrode membrane having input and output lines is bonded to one end surface of an inductive ceramics sample to generate ultrasonic pulses of about 17 MHz. The propagation attenuation of sonic waves is measured by the oscilloscope and, from the attenuation curve thereof, a sonic wave absorbing coefficient is calculated. When this value is excessively large, non-load becomes large or fine cracks are present in the ceramics material. By this constitution, the characteristics of the ceramics material can be evaluated. |
