Slinky stator: The impact of manufacturing process on the magnetic properties

The manufacturing of a slinky stator core is the result of a sequence of difference processes: straightening, punching, rolling It has been shown in the literature that manufacturing processes lead to a degradation of the magnetic properties. However, it is really difficult from the state of art to classify them a priori from the most influent to the less. In order to determine the most influent processes, it is necessary the evaluate quantitatively the impact of impact of each process. In this paper, a campaign of magnetic characterization is carried out on FeSi 1.3% specimens extracted after each process on the manufacturing line of a slinky stator. Samples have different shapes, so different characterization methods were used to determine the normal curves and total losses. Results show that the dispersion in raw material is quite important and depends on the level of induction. Straightening and training processes deteriorate the magnetic material properties and dispersion after both processes is higher than the raw material one. The effect of rolling and cutting are the most harmful compared to the other manufacturing processes, while the compacting process shows a benefic effect.