Characteristics of power loss in soft magnetic composites a key for designing the best values of technological parameters

Abstract

In this paper, we consider a new way to choice values of technological parameters, such as compaction pressure and hardening temperature which are required during preparation of soft magnetic composites. The novel approach based on an optimization of power loss in soft magnetic composites. The power losses have been measured in Somaloy 500 samples for a wide range of frequency and magnetic induction. These samples have been prepared under a wide range of compaction pressures and hardening temperatures. The power loss characteristics have been derived by assuming that investigated samples obeyed the scaling law. Agreement obtained between the experimental data and the scaling theory has confirmed this assumption. Moreover, the experimental data of the given sample have been collapsed to a single curve which represented measurements for all values of frequency and magnetic induction. The scaling transforms the loss characteristics from the two dimensional surfaces to the one dimensional curves. The samples were produced according to two methods: for different pressures with constant temperature and at different temperatures with constant pressure. In both cases the power losses decrease with increasing pressure and with increasing temperature. The reduction of power losses with increasing compaction pressure and hardening temperature respectively, stops for their certain critical values. Above these values, the power losses increase suddenly. The aforementioned, the critical pressure and the critical temperature are sought after solutions for optimal values. In order to reduce the parameters values set, the limit curve has been derived in the pressure–temperature plane. This curve constitutes a separation curve between the parameters values corresponding to high and low losses.