Minimalistic Devices and Sensors for Micromagnetic Materials Characterization

Micromagnetic materials characterization requires sensors which essentially consist of two critical elements: an electromagnet which introduces a well-defined magnetic field to the material, and a sensor system which detects the material´s response to the applied magnetic field. The devices developed at Fraunhofer IZFP obtain a multiparametric “magnetic fingerprint” with these sensors by means of several methods. The magnetic fingerprints of calibration samples are used as input for pattern recognition or regression analysis, thus allowing the prediction of mechanical-technological material characteristics (hardness, yield strength, etc.) or residual stress. This approach is called micromagnetic multiparameter microstructure and stress analysis (3MA). The long-term stability and reproducibility of the sensor and device characteristics are crucial for the reliability of the measured results. Therefore, the measuring hardware should follow a minimalistic approach. In this paper, we propose a way of simplifying the measuring hardware by multiple use of sensor elements, reducing the analog signal processing chain and transferring most signal processing tasks to the PC.