Development And Test Of Metal Magnetic Memory Testing Instrument

Metal magnetic memory technology is a kind of non-destructive testing technology which rising in recent years. Compared with other conventional electromagnetic non-destructive testing techniques, it does not require an excitation source, coupling agents, and it does not need to perform any of the workpiece surface inspection process. It is a kind of safety and environmental protection detection technology. Since its birth, it has drawn attention of numerous researchers, engineers and technicians by its advantage of early-stage pre-diagnosis of the ferromagnetic component and is widely used in the actual testing equipment of ferromagnetism. But as a "young" non-destructive testing technology, researchers cannot ignore its immaturity. So in practice detection process of magnetic memory testing missing and false detection often occur. The fundamental reason is that current research on NDT techniques in information extraction level magnetic flux leakage signal is not perfect, which can not make full use of the information of collected signals to improve the reliability and credibility of the testing results. This article is a breakthrough in signal analysis, searching for information about the magnetic flux leakage signal that may be more practical to detect magnetic memory, in order to provide technical support to further improvement of the metal magnetic memory technology.This article firstly analyzes the shortcomings of the current development of magnetic memory testing method and magnetic memory testing technique, with two-dimensional magnetic memory technology as the basis of the research projects, while extracting the surface magnetic flux leakage signal component tangential component of H(x) and normal component of H(y) as an indicator of the two signals together to achieve the dual criterion, accurately determining the stress concentration sites. And then it analyzes and evaluates the force to achieve good calculation of component phase gradient.Secondly, using three kinds of programming languages-- Python, C language, and LabView achieved the coding of the three-dimensional magnetic memory detection system, and the Raspberry Pi core as well as the PC platform were used as a data processing system. At the same time, high-speed, reliable two-dimensional magnetic memory probe has been developed to meet the measurement environment and demand. By way of writing programs to achieve the design of digital filters and adaptive technology gradient method, in order to assemble a high-performance two dimensional magnetic memory testing equipment.In the end, by two classic experiments: flat tensile and fatigue test, it verified that magnetic memory testing instrument can not only make accurate judgment of stress concentration, but also have relatively good proficiency assessment for health condition of damaged part. It provides an effective experimental basis for quantitative analysis of magnetic memory technology with high reliability and practicability.