Gao Q.-Q.,Shenzhen University |
Gao Q.-Q.,Key Laboratory of Functional Materials of Shenzhen |
Gao Q.-Q.,Shenzhen Engineering Laboratory of Advanced Technology for Ceramics |
Xiao C.,Shenzhen University |
And 12 more authors.
Wuhan Ligong Daxue Xuebao/Journal of Wuhan University of Technology | Year: 2014
In order to improve the magnetic and mechanical properties of soft magnetic composites, phosphate processing was used to prepare an insulation layer on the surface of pure iron powders. Abulk soft magnetic composite was prepared by means of powder metallurgy processing. The effects of phosphate concentration on the density, resistivity, microstructure and magnetic properties were studied. The experimental results show that with the increase of phosphate concentration, the resistivity of the soft magnetic composites increases rapidly, but the density, maximum saturation induction intensity and magnetic permeability decrease. When the phosphate concentration is 0.005, the best combination of the relative density of 89.74% and the magnetic properties is obtained. The maximum saturation induction intensity is 1.442 T and the magnetic permeability is 375 H/m. Stereoscopic microscope, SEM and EDS analysis show that after phosphate processing, the surface of the iron powder is coated completely and uniformly by an iron phosphate insulating layer. The thickness of the insulating layer increases with the increase of phosphate concentration.