Five flaw detection methods for titanium materials----ultrasonic flaw detection

The frequency range of sound waves that people's ears can directly receive is usually 20Hz to 20kHz, that is, the sound (sound) frequency. The frequency below 20 Hz is called infrasound, and the frequency above 20 kHz is called ultrasonic. In industry, ultrasonic waves of several megahertz are commonly used for flaw detection. When the ultrasonic frequency is high, the propagation linearity is strong, and it is easy to propagate in solids, and it is easy to reflect when it encounters the interface formed by two different media, so it can be used for flaw detection. Usually, the ultrasonic probe is in good contact with the surface of the workpiece to be detected, and the probe can effectively transmit ultrasonic waves to the workpiece and can receive the ultrasonic waves reflected from the (defect) interface, convert them into electrical signals, and then transmit them to the instrument for processing. According to the speed of ultrasonic propagation in the medium (often called the speed of sound) and the propagation time, the location of the defect can be known. When the defect is larger, the reflecting surface is larger, and the reflected energy is larger, so the size of each defect (equivalent) can be checked according to the size of the reflected energy. Commonly used flaw detection waveforms include longitudinal wave, transverse wave, surface wave, etc. The former two are suitable for detecting internal defects, and the latter is suitable for detecting surface defects, but they have high requirements on surface conditions. 6al4v titanium sheet