Effect of Granulometry and Oxygen Content on SMC Magnetic Properties

Abstract

The interest around the adoption of Soft Magnetic Composite materials (SMC) in the realization of electric machines, or parts of electric machines, is continuously increasing. The main reason lies on the opportunity to realize magnetic circuits following a 3D design procedure, which is not allowed with the adoption of the traditional lamination sheets. This is not the only reason, as a lot of research is being carried out on the losses distribution in the magnetic material, particularly as function of the frequency. In this paper different iron powders have been analyzed to investigate the impact of the granulometry on the SMC performance; in particular the grain size and the oxygen content have been considered variable parameters. The materials, prepared, compacted and tested in our laboratories, have been characterized to obtain the magnetic characteristic and information about the iron losses.

Different Formation Routes of Pore Structure in Aluminum Powder Metallurgy Alloy

“…Murphy [32] declared that obvious changes in the loss of particle boundaries were characterized and quantified properly, but the smoothing of the pore edges with the resultant loss in a specific area was not detected. It is a well-known phenomenon [5,30,33] that an atomized technique produces most surface oxides on the aluminum base alloys, which are removed in a subsequent annealing process; nevertheless, a layer of oxides will still cover the surfaces of the heat-treated powders. It is important to reduce surface oxides during the sintering process in order to get a proper “sinter neck” between the adjacent particles.…”

Recent Advances in Multi-Functional Coatings for Soft Magnetic Composites

“…Furthermore, some phenolic resins are supplied in the form of powders, such as Novolac, simplifying their use [128,129]. Different types of ferromagnetic powders can be coated [19,128,130,131] and the production process combines metallurgical and polymeric processes [130,132]. Several phenolic resins commercially available were considered in [133].…”

“…The granulometry of the powders [19,20] and the number of pores [21] in the final component are critical parameters in the SMC mixes. As for the latter, it is well known [22][23][24] that pores act as crack initiators.…”

Archives of Metallurgy and Materials

“…on the other side, the poor fatigue and wear resistance in additively manufactured titanium alloys is caused by high porosity levels. there have been multiple types of porosity observed in these materials [12][13][14][15][16][17][18].…”