Ultrasonic detection of acoustic wave technology

The use of ultrasonic technology to carry out non-destructive testing of the interior of the solid, began in the 1920s and 1930s, the Soviet scientist Sokolov took the lead in the use of ultrasonic technology to check the concept of defects within the metal, published the results of the test in 1935 using the penetration method, and at the same time applied for the right to detect defects in the material. Under these conditions, the first penetration method inspection instruments were created, but the technology uses one transmitting and one receiving probe, and the placement of the probes needs to be kept relative to each other, so the scope of application is greatly limited. With the development of this technology, in the 1940s, the emergence of pulse-reflective ultrasonic flaw detector, to the non-destructive testing technology has injected new vitality. In recent years, ultrasonic testing technology is endless, from the initial penetrating and A pulse reflection ultrasonic instruments to digital ultrasonic instrument, diffraction time difference method ultrasonic instrument, phased array ultrasonic instrument, etc., ultrasonic testing technology has made great progress and development, the technology has established an extremely important position in industrial manufacturing, widely used in the iron and steel industry, machine manufacturing industry, special equipment, ship and aerospace industry, nuclear industry and other important Industrial sector. Our company's ultrasonic technology is mainly used in the manufacturing process of energy equipment (hydroelectric generators, steam turbine generators, nuclear power plants), quality control of raw materials and products in the production process.
Ultrasonic testing uses ultrasonic wave propagation characteristics in the workpiece, the emission phenomenon that occurs when the sound wave encounters the interface between two media with different acoustic impedance. The working principle is that the sound source generated by the pulse wave into the workpiece, ultrasonic waves in a certain direction and speed forward propagation, when encountered on both sides of the interface with different acoustic impedance, part of the sound wave reflection back to be received by the detection instrument, analysis of the reflected acoustic wave amplitude and position and other data, and then assess the workpiece is good or bad and the existence of defects in the size, location, and nature of the information, in general, to find the defects and their assessment of the following three aspects: (1) whether the acoustic signal and amplitude from the defect; (2) the distance between the incident acoustic wave and the received acoustic wave; (3) the energy attenuation of the acoustic wave through the material.
Ultrasound is a mechanical wave, which is mechanical vibration propagated in the medium. Some theorems and concepts of geometric acoustics and physical acoustics are mainly involved in ultrasonic detection. Such as conventional ultrasound using geometric acoustics in the law of reflection, refraction and waveform conversion, diffraction time difference method and phased array detection technology mainly using geometric acoustics in the law of reflection, refraction and physical acoustic wave diffraction and superposition. Mechanical wave description of the main physical have period, frequency, wavelength and speed.