Surface Integrity Inspection on Gears Using Barkhausen Noise Analysis

Hard finishing of gears is the last step in the process chain and it is mostly responsible for the properties and performance of the workpiece. A grinding process basically offers the possibility of high temperatures in the cutting zone, possibly resulting in tensile residual stresses, reduced hardness and in metal structure. Thus the control of physical properties of the workpiece is of utmost importance for quality assurance. This paper shows the testing of finished gears in industrial production with a nondestructive, ecological and micro-magnetic method called Barkhausen noise analysis. The strength of Barkhausen signal is influenced by the elastic stresses and the micro structure. So, changes in residual stresses and material structure are measurable. Moreover they are indicators for improvement of the used grinding process. This paper focuses on the possibility to substitute other more hazardous methods by Barkhausen noise analysis. In addition process advantages and drawbacks factors influencing measurements industrial applications and options for measuring automation are also discussed.