Study of the system Iron-Manganese-Aluminium and its alloys

Abstract

This work of critical review on the system Fe-Mn-Al and their alloys was undertaken to study the theoretical basis if any, for the possibility of developing suitable magnetic materials made of iron-manganese-aluminum or iron-manganese-aluminium-carbon. The importance of magnetic materials either soft or hard needs no emphasis. The growth and development of each new magnetic materials has been in answer to meet some special demands, or as an economic substitute entailing lower coast or to using available raw materials only. The quest for materials with new and improved magnetic properties had passed through many stages starting with the earliest steels followed by steels containing tungsten, chromium, cobalt chromium-cobalt, cobalt-tungsten, and molybdenum. Amongst the carbon less alloys the aluminium-nickel, aluminum-nickel-cobalt, Iron-nickel-copper and oxide magnetic have been known. The complex carbon less alloys of recent years have brought about remarkable changes in modern electrical machinery and devices with their extraordinary performance and energy. This was inconceivable in case of tungsten, chromium and cobalt steels. The rise to prominence of the ‘Alnicos’ and the anisotropic ‘Alcomax’ is only too well known. Amongst the soft magnetic products, high permeability materials like pure iron, iron-silicon alloy, iron-silicon-aluminium alloy, nickel iron alloys, permalloys and nickel manganese alloys ar known, The development of ‘perminvar’ and ‘isoperms’ has been in answer to the search for constant permeability materials. High saturation value materials like ‘Hiperco’ and ‘permendue’ Are also known, and high resistivity sintered oxides known as forrites have recently become prominent. Nevertheless, the search for better or cheaper substitutes is still on. With a view to employ indigenous products such as Fe,Mn and Al, easily available in the country, a scheme is undertaken to explore the possibilities of developing magnetic alloys using these materials. As a preliminary to the investigation, published literature on the subject has been reviewed.