Plastic Deformation of Iron-Nickel Invar Alloys

Plastic deformation of FeNi invar alloys which have peculiar magnetic properties is studied by means of the tensile and stress relaxation tests. The plastic properties of these alloys in comparison with other face centred cubic alloys are characterized by the large temperature dependence of the flow stress, the straight dislocation configuration, and not having clearly defined three-stage hardening. These results reveal a contribution to the resistance to dislocation motion from the drag due to making the new region of the magnetization decrease around a dislocation.