Enhanced magnetic and mechanical properties of gas atomized Fe-Si-Al soft magnetic composites through adhesive insulation

Abstract

Herein, adhesive composite insulating coatings containing epoxy resin, MgO and aluminum dihydrogen phosphate have been developed to obtain Fe-Si-Al soft magnetic composites (SMCs) with enhanced magnetic and mechanical properties. The influences of MgO content, MgO particle size and water content on magnetic and mechanical properties have been comprehensively investigated. It is shown that MgO can not only improve the curing quality of aluminum dihydrogen phosphate to enhance tensile strength, but also reduce eddy current loss by breaking conduction path. The water content determines the viscosity of the aluminum dihydrogen phosphate solution, thereby affecting the curing quality of the insulating layer. The content and particle size of MgO affect both the curing quality of the aluminum dihydrogen phosphate insulating layer and the uniformity of the insulating layer. When the experimental parameters have been optimized, the green strength can reach 51.66 N and product strength also exceeds 30.32 N. Meanwhile, permeability, core loss and DC-bias performance can also be effectively optimized via adjusting insulation layers. This work may shed new light on developing multi-functional insulation coating for SMCs products, and pave the way for researching adhesive insulation layer.