Study On The Reconstruction Of The Defects In The Rod By Four Axis Fully Automatic Water Immersion Method

With the development of the society,all kinds of materials made of the workpiece are used in various fields.The work piece in the manufacture and use will inevitably have some damage,if left unchecked,easy for future production and life safety hazard.At this time,it is very important to detect the defects of the work piece.In recent years,ultrasonic testing technology has been developed rapidly and has been widely used in various fields.Ultrasonic water immersion test is a method to improve the efficiency and quality of ultrasonic detection,the automation of ultrasonic water immersion is of great significance to the realization of intelligent ultrasonic testing.The accurate control of ultrasonic water immersion testing system can provide great help for the detection of material defects and the analysis of defects.Firstly,the ultrasonic nondestructive testing technology is introduced in detail.The research status and development trend of ultrasonic nondestructive testing technology at home and abroad as well as the basic principle,application scope and advantages in defect detection are elaborated in detail.The concept and principle of ultrasonic water immersion method based on ultrasonic testing are explained,and the advantages of the ultrasonic testing method are described.It provides theoretical support for the practical application of ultrasonic testing technology.We first use hand held probe to detect defects of self-made metal rod specimens,including the selection of probes and coupling agents,and a brief description of experimental equipment parameters.It is found that the hand-held probe's direct contact with the specimen is not easy to operate,and in practice,because the environment and the location of the specimen are not ideal,it is difficult for the inspector to use the handheld probe to detect it.Compared with the direct contact method,the ultrasonic water immersion method has many outstanding advantages,so a method of replacing artificial with PLC controlled walking mechanism is designed to detect the defect of metal specimen by ultrasonic water immersion method.The walking mechanism in the detection system,the software system of PLC control and the data acquisition system are described in detail.After collecting the defect waveform,the Born approximation method is used to reconstruct the collected data by MATLAB7.0 programming.The result of reconstruction shows that the shape of the defect of the specimen can be judged basically,which has certain practical significance for the application of the defect detection of the rod shaped work piece.