A：Ultrasonic flaw detection is a physical non-destructive test method that uses ultrasonic waves to directly inspect internal defects on ingots. During the inspection, the directivity of the sound beam and the time required for the sound wave to return from the defect can be used to locate the defect; the sound is reflected or penetrated by the energy to quantify the defect; according to the size, shape, shape and distribution of the defect The waveform characteristics characterize the defect.
There are many methods for ultrasonic flaw detection. The method of detecting the ingot in the aluminum processing plant in China is the automatic flaw detection method of longitudinal wave pulse reflection water intrusion; the principle of this method: before the flaw detection, the ingot is placed on the rotating wheel of the water tank, and then the center The cart with the probe rides on the ingot and places the probe on the normal to the axial direction of the ingot. In the case of flaw detection, the ingot is rotated at a uniform speed, and the flaw detection vehicle advances at a uniform speed in the longitudinal direction, so that the ultrasonic beam forms a spiral scan on the ingot, and in the process, when the ultrasonic wave emitted by the probe hits the defect interface, reflection occurs, and Return by the meta-path, convert it into a high-frequency electric pulse by the probe, and display it after amplification. The longitudinal position of the defect is the position of the probe. The depth of the defect is generally not located in the so-called inspection, and then the defect is quantified according to the "equivalent method", and finally the defect is characterized according to the characteristics of the reflected flaw detection pulse.
Ultrasonic flaw detection has the characteristics of sensitivity, accurate inspection, no damage to the ingot casting, convenient operation, fast, and no harm to the human body. This advanced technology was put into use in the aluminum processing industry in China in the 1980s, mainly for the inspection of special products. Cracks, slag inclusions, pores, etc. in the ingot of the cast ingot destroy the continuity of the metal.