Material Characterization using Barkhausen Noise Analysis Technique - A Review

Background/Objective: Material characterization is an essential part during manufacturing cycle of component as it assesses the surface integrity of component. Assessment of surface integrity is important since it decides the fatigue strength and service life of manufactured component. Microhardness, microstructure and residual stress are key elements of surface integrity. Modern manufacturing industries relies on laboratory based technique such as microhardness tester, optical metallographic inspection and X-ray Diffraction (XRD) techniques for measurement of key elements of surface integrity. The laboratory based techniques are not eco-friendly and as well as time consuming. Methods/Statistical Analysis: Barkhausen Noise (BN) analysis is a preferred and advanced technique for material characterization when an external magnetic field is applied over a ferromagnetic material, it changes the global magnetization occurs by motion of magnetic domain wall as these domain wall align these stress in the direction of applied magnetic field. A voltage pulse is generated due to motion of magnetic domain, which can be detected as signal by sensor. This included voltage pulse is known as BN signal. Findings: Conventional material characterization techniques such as hardness tester, optical microscopic and XRD are extensive time consuming laboratory based technique and difficult to integrate in manufacturing environment. On the other hand, BN technique is less costly, fast, eco-friendly NDT which can be easily integrated with manufacturing cycle for component. Application: Barkhausen Noise measurement is generally associated with hysteresis loop measurement.BN signal parameters such as Root Mean Square (RMS) value, amplitude, peak position as well as hysteresis loop properties coercively, remanence are sensitive towards change in micro-hardness, microstructure In this way, BN analysis technique can assess the surface integrity of manufactured component. In the present review paper, a critical and wide literature survey is conducted to summarize and highlight the successful attempts of BN techniques for surface integrity assessment of components, by using various manufacturing process such as machining, welding, heat treatment and grinding. Keywords: Barkhausen Noise Measurement, Microstructure, Non Destructive Testing, Residual Stress, X-ray Diffraction