Design And Verification Of Barkhausen Noise Detection System For Aviation Gear Materials

Aviation gear is key component of the aviation engine. It is easy to deform under the influence of alternating load and severe impact during the process of using, which can affect the performance of the gear. This paper attempts to use plastic deformation stage of aviation gears material using Barkhausen noise detection, and analysis of the plastic deformation of the material properties which lead to the change of the Barkhausen noise signal.Firstly based on the electromagnetic theory, Barkhausen noise signal generation mechanism and characteristics was expounded, and on the basis of these theories, a set to conform to the requirements of the MBN detection system has been designed. The detection system is divided into hardware part and software part. The hardware part includes signal generator, power amplifier circuit, detection probe, signal conditioning circuit, power circuit and acquisition card. The software was set up based on the MATLAB compiler environment, including the acquisition card driver, data preprocessing and signal feature extraction. This paper introduced the design process of each part. Then using the detection system detected the 18Cr2Ni4 WA steel which is commonly used in aviation gear. And Barkhausen noise signal change characteristics of the material plastic deformation was studied and its causes was analyzed. Finally, the experiment was designed using X- ray diffraction method and metal magnetic memory method to compare with the Barkhausen noise method.The experimental results show that the optimal excitation parameters of the detection system are 300 mV, 60 Hz. The characteristics of Barkhausen noise signal value show a decreasing trend with the increase of the amount of plastic deformation, which is mainly caused by the dislocation multiplication and the residual stress caused by plastic deformation. Comparison of X-ray diffraction shows that the dominant influence of dislocation pinning effect is the proliferation of Barkhausen noise signal. With respect to the Barkhausen noise signal peak to peak and root mean square(RMS), the number of rings on the material plastic deformation have higher sensitivity and better correlation, which is the optimal material characteristic value detecting plastic deformation. Magnetic memory signal method normal component HP(y) value zero position increases to final fracture location approach with specimen plastic deformation by the metal magnetic memory method. And gradient magnetic field |K| values gets maximum value when specimen enters the stage of plastic deformation, then decrease rapidly until it stabilize. Test of metal magnetic memory method and Barkhausen noise method are similar and complementary, can both be integrated to detect aviation gear.