Barkhausen Noise as a Reliable Tool for Sustainable Automotive Production

This paper deals with the sustainable production of components in the automotive industry, with the focus on the nondestructive evaluation of components after plasma nitridation via the Barkhausen noise technique. This study investigates the influence of tool wear on surface state after turning, and the consecutive plasma nitriding process. Moreover, position in the nitriding chamber and the corresponding heterogeneity of components is investigated as well. The results of experiments indicate that an increasing mechanical and thermal load due to flank wear and the associated process dynamics negatively affects the heterogeneity of the surface state after turning, and consecutive nitriding in terms of Barkhausen noise emission. Moreover, it was found that the conditions in the chamber during the nitriding process vary and, especially near the venting system, the temperature is slightly lower, such that some components are found to be unacceptable as well. The study also unwraps the contribution of the diffusion and compound layers with respect to MBN and discusses the contribution of the MBN pulses of different frequencies. The pinning strength of nitrides is indicated with respect to their size and the related thickness of DWs. Finally, this study clearly demonstrates how the MBN technique can be employed for the monitoring nitrided components and the corresponding optimisation of manufacturing cycles.