Thermal and Structure Properties in Ferromagnetic INVAR Alloys Prepared by Powder Metallurgy Processes

Abstract

In order to understand the INVAR, effect in 3D-transition metal alloys . the Fe3. * Nix alloys with x= 0.35.0.50,0.70 have been chosen .Experiments have been made on thermal and structural properties to study the physical origin of INVAR characteristics such as : thermal expansion . phase transition, and curie temperature Tc which are closely related to its ferromagnetism .Fe0.65 Ni0.35 shows an anomalously small thermal expansioncoefficient below the curie temperature with ( FCC ) structure . This behavior has not been found in other combination.The structural results show that the ( BCC ) phase occurs above 50% Ni and does not effect (lie INVAR behavior. The results are discussed with the relation between thermal and structural properties with respect to theSciencemagnetic transformation .