Improvement of stress testing performance using Barkhausen noise sensor

This paper focuses on the occurrence of magnetic barkhausen noise (MBN) when the ferromagnetic material is under an alternating magnetic field in a localized zone. It encompasses the formation of a magnetizer with alternating magnetization function of low frequency and the characteristics of concentrated line of magnetic induction. Using molecular intercalation technology to control the distribution mode of the metal ions and anions, located inside and between the layered double hydroxides (LDHs) laminate respectively, the highly ordered NiZnFe2O4 spinel type ferrite which receives the weak MBN signal is synthesized. With the aid of hardware circuit, the interfering noise of the MBN signal is eliminated through research involving low noise amplication, band-pass filtering and frequency-selective amplication. The highly selective, instant, fixed point, high-speed and portable MBN stress testing sensor has also been successfully researched. Additionally, the feasibility of applying the magnetizing frequency ratio method and the high-intensity magnetizing field method to engineering stress testing and heat treatment state is also studied.