Development Of Barkhausen Intelligent Detection Equipment For Ferromagnetic Material

Ferromagnetic materials have been widely used in industries for a long time, such asmechanical equipment, instrumentation, water conservancy, electric power equipment, defenseweapons and so on. According to the different performance requirements, reasonable heat treatmentwill be chosen to enhance the performance of ferromagnetic materials by changing their structure inindustry. Therefore, detection of ferromagnetic materials structure after heat treatment is alwaysfocused by engineering and technology. The main content of my topic is, to set up the intelligenttesting equipment which is based on the research of the theoretical of Barkhausen noise, and toanalyze the impact of structure on MBN noise signal from microscopic veiw. Many experiments aredone to explore the relationship between microstructure parameters and MBN noise signal.First, based on the electromagnetic theory, this thesis analyzed the generation nature and testingmechanism of Barkhausen signal, introduced the MBN signal characteristics, deeply studied the mainphysical factors of Barkhausen signal, including magnetic field intensity, stress and microstructure,etc. Then, on the basis of the preliminary work we set up the intelligent testing equipment which isbased on the theoretical of Barkhausen noise, and introduce each part of the hardware and software ofthe equipment in detail. Finally, intelligent testing equipment is used for the material of gear forrelevant test. The relationship between the hardness and MBN signal is verified and effectivehardened layer depth is obtained that has a great impact on MBN signal by correlation analysis. BPneural network model and experimental curves of different excitation frequencies are used, trying toestablish the correspondence not only between MBN signal and hardness, but also between MBNsignal and effective hardened layer depth.