Research on Ultrasonic Nondestructive Testing Algorithm for Metal Materials

¹ School of Mechanical, Manufacturing and Energy Engineering, Mapúa University, Manila, Philippines; School of Intelligent Manufacturing, Leshan Vocational and Technical College, China
² School of Mechanical, Manufacturing and Energy Engineering, Mapúa University, Manila, Philippines
³ Karamay Sanda Limited Liability Company, Xin Jiang, China

^a lnwei@mymail.mapua.edu.ph
^b adcalderon@mapua.edu.ph
^c 404878181@qq.com

Abstract

With the continuous development of science and technology, metal castings are widely used in aerospace, oil exploitation and other fields, and the safety and availability of casting quality has become a hot issue in current research. Ultrasonic nondestructive testing has good penetration and directivity, but nonstationary ultrasonic signals will be formed in the process of flaw detection, which has a certain impact on the extraction of effective information. Therefore, by processing and analyzing ultrasonic signals, this paper uses wavelet transform and empirical mode decomposition to make a comparative study. It is found that the wavelet transform denoising algorithm still has distortion after processing the noisy signal. Empirical mode decomposition is based on the signal itself, which has strong adaptability and better performance. Moreover, the improved threshold function has higher accuracy in signal processing, and the distortion degree of waveform is reduced, which is more suitable for noise reduction of metal echo signal, and can meet the requirements of engineering applications.