The Study On Technology About Nondestructive Testing Of SiCp/Al Composites

Based on studying the fabricating process and mechanical properties of SiCp/Al composites, necessaries of nondestructive testing on SiCp/Al composites are presented in this paper. Due to the high damping property of SiCp/Al composites, ultrasonic testing method is chosen from several nondestructive testing ones. Furthermore, the testing device is developed and the testing scheme is designed. In order to deal with effect of the high damping, focusing probe with focused sound field is used in testing. The image device of ultrasonic C-scanning, which has functions of ultrasonic testing, PC-Based Control, data collection, data storage, data processing and image displaying together, is applied in testing for the sake of visual testing result. At the time of image processing, both size and shape of defects may be analyzed and measured according to the sound pressure distribution of focusing probe. And essence of the defects can be judged. In SiCp/Al composites, the main defects are hole and very inhomogeneous distribution of SiC particles.From the testing result, it is obvious that both the image and location of defects can be accomplished by use of the image device of ultrasonic C-scanning, which is especially effective for testing planar defects. The images of defects are very clear, so it is easy to determine essence of defects. This device is suitable for nondestructive testing on big size workpiece of SiCp/Al composites and has high practicability. Combined with focusing probe, the testing precision is improved, and both size and shape defects may be measured directly. In a word, the image device of ultrasonic C-scanning has wild application in nondestructive testing of industrial production.