Influence of Humidity Variation on the Surface Deffects and Soft Magnetic Properties in the Fabrication of Fe Based Amorphous Alloy Ribbon by the PFC Process

This study was carried out to investigate a influence of humidity variation (%) on the magnetic properties and the surface flaws in the fabrication of Fe-based Fe78Si9B13 amorphous alloy ribbon by Planar Flow Casting process. As a result, the size of the air pocket and the droplet which is observed in the contact surface and the free face of the amorphous alloy ribbon becomes large when the humidity increases and the size highly increases with the surface roughness at the same time. Especially, the surface roughness value which is made in the 65 % of the humidity is the lowest in the contact surface (Ra = 0.60 mu m, Rz = 3.11 mu m) and the free face (Ra = 0.47 mu m, Rz = 3.00 mu m). Also, in case of the soft magnetic property of the magnetic core which is made with the toroidal core of 23(OD)*20(ID)*20(H)size, in the sample of the amorphous alloy ribbon which is made in 65% of the humidity, the most excellent value is gained as B-s(B-700) = 1.055 T, H-c = 0.083 Oe, permeability = 1,197 and core loss -0.276W/kg.