Wear, corrosion, material fatigue—these signs of degradation are common to most materials. This makes it all the more important to detect damage early, preferably on the micro-scale. Magnetic test methods are often used for this purpose, which was previously impossible with non-magnetic steel. Researchers from Kaiserslautern and Mainz have now developed a process in which they apply a thin magnetic layer to steel. Changes in the microstructure can thus be detected by changes in magnetic effects. Materials such as aluminum can also be tested in this way. The study was published in the Journal of Magnetism and Magnetic Materials.