Preparation of Fe and Co based amorphous wires by in-water quenching process

Abstract

The investigation addresses the effect of in-water quenching process parameters on the magnetic properties of Fe and Co based amorphous wires. The in-water quenching process parameters such as water drum speed, crucible nozzle orifice diameter, crucible nozzle to water level separation and gas pressure for melt ejection were found to be critically important to obtain continuous and ductile wires. The thinner wires with a diameter of ∼124 μm revealed superior soft magnetic properties with coercivities as low as ∼5˙63 A m^–1 (70˙8 mOe) which was attributed to their high amorphous nature and consequent isotropy. This was also manifested from their surface morphology as observed by scanning electron microscopy. The Fe_77˙5Si_7˙5B₁₅ and Co_72˙5Si_12˙5B₁₅ (at.-%) wires in their as prepared state revealed high fracture strength, above 3000 MPa, and high microhardness ∼1200 HV (Vickers pyramid number).