Iron Base Alloy Plate Material for Voice Coil Motor Magnetic Circuit Yoke and Yoke for Voice Coil Motor Magnetic Circuit

摘要

PURPOSE: To provide an inexpensive magnetic circuit which does not require the formation of a corrosion resistant metallic film. CONSTITUTION: An iron alloy sheet material for a voice coil motor magnetic circuit yoke consists of a iron alloy having a composition containing 0.0001 to 0.02% C, 0.0001 to 5% Si, 0.001 to 0.2% Mn, 0.0001 to 0.05% P, 0.0001 to 0.05% S, 0.0001 to 5% Al, 0.001 to 0.1% O, 0.0001 to 0.03 % N, 0 to 10% Co, 0 to 10% Cr and 0.01 to 5% of alloy elements selected from Ti, Zr, Nb, Mo, V, Ni, W, Ta and B, and the balance Fe, has a sheet thickness of 0.1 to 5 mm, a magnetic field intensity variation of 0 to 10 Hz, a saturation magnetic flux density of 1.7 to 2.3 tesla, the maximum specific permeability of 1,200 to 22,000 and a coercive force of 20 to 380 A/m.