Ultrasonic C-scan Feature Imaging System Development Based On VB.NET

With the development of industrial and the improvement of the bearing capacity of materials and components,defect control requirements and detection sensitivity in materials and components have improved a lot.For example,the evaluation of interface bonding quality of titanium-steel explosion welding and bonding quality of bonding structure,and ultrasonic testing of minor defects in magnesium alloy inclusions.It is difficult to meet the detection requirements of minor defects within the material with the use of conventional A-scan detection methods.Therefore,an ultrasonic C-scan feature imaging detection device needs to be developed for ultrasonic C-scan imaging detection of workpieces and materials.Based on comprehensive analysis of existing ultrasonic C-scan detection functions and technical indicators,this paper developed a VB.NET-based ultrasonic C-scan feature imaging detection equipment,the device uses a modular design,the hardware part includes the host computer,mechanical scanning platform,motion control unit,ultrasonic signal detection unit,etc.The software part includes motion control module,ultrasonic data acquisition card driver module,ultrasonic A-scan signal acquisition and display module,ultrasonic C-scan imaging detection module,ultrasonic C-scan feature imaging and images processing module.The minimum scanning speed of the developed system is 0.2mm step,and the maximum scanning speed is 6000mm/min;the ultrasonic signal detection unit can match 0.1~20MHz ultrasonic probes,the highest sampling frequency is 1Gs/s;the equipment has ultrasonic A-scanning signal acquisition and display function,ultrasonic C-scan imaging detection function and ultrasonic C-scan feature imaging and image processing functions.Ultrasound C-scan feature image can be achieved through the use of position mapping,color mapping,ultrasound echo signal amplitude and Hilbert signal processing to extract envelope value and other characteristic values for ultrasound detection data for image rendering.On the basis of completing the system's hardware and software design,in order to verify the system's detection results and performance indicators,related tests were conducted.Among them,the titanium-steel explosion welding test has obvious effect on the surface ripple,the measurement result error is 9.93%,and the system detection accuracy meets the detection requirements of the titanium-steel explosive welding layer ripple and small defects.The Hilbert signal processing of the ultrasonic detection signal was performed on the aluminum plate cementation layer to measure the amplitude of the envelope.The imaging results showed that the system had a high defect detection rate,the measurement result error was 1.84%,The detection accuracy meets the project testing requirements.The results of the defect detection of magnesium alloy inclusions indicate that the system can detect the minimum defect size of about 100 ?m to meet the project inspection requirements.Through experiments,the ultrasonic C-scan feature imaging detection system developed in this paper satisfies the requirements of project detection.The system has a good detection effect and stability,and can be applied to other workpiece inspection requirements.The system has reached the level of practical application.