Manufacturing of high purity iron foils and applications

Abstract

The presented work investigates a novel method to manufacture 98.8 percent pure iron strips having high permeability and better saturation flux density for application in magnetic flux shielding. The proposed method uses electro-deposition and cold rolling along with intermediate annealing in a controlled environment to manufacture 0.5-0.05 mm thick pure iron strips. The presented approach is inexpensive, has better control over scaling/oxidation and requires low energy than that of the conventional methods of pure iron manufacturing by pyrometallurgical methods. The proposed method uses iron chloride solution in the electrolysis process which require close control over the pH value and purity of the electrolyte solution. The electrode position process has been followed by cold rolling which ensures 15-20 percent reduction in the thickness in each of the cold rolling pass. Further controlled environment annealing has been performed after every cold rolling pass to ensure defect free pure iron strips. Spark emission spectroscopy measurement has ensured that the iron manufactured during the process has 99.8 percent purity. newlineImportant magnetic and mechanical properties of pure iron have been investigated in context to the application of the material in magnetic shielding. Magnetic properties of the material have been investigated by following VSM and IEC60404-4 standard and toroidal coil test to determine hysteresis curve, magnetic permeability and core losses. Disc shaped specimens have been prepared as per IEC60404-4 to determine the initial magnetisation curve and B-H loop of the pure iron manufactured in the present study. Magnetic characterisation results validate that the pure iron manufactured in the present study has higher magnetic permeability and better saturation flux density, which are in consonance with the findings for pure iron reported in the literature. It has been identified that the pure iron material is suitable for magnetic shielding applications.