Experimental evidence for magnetic or electric field effects on phase transformations

This review presents examples of the effects of magnetic or electric fields on phase transformations in a variety of materials. Magnetic fields have been shown to influence phase stability and, for example, induce martensite in iron-base alloys. Application of a magnetic field during the growth of some phases can produce an alignment with the field and an optimized microstructure for certain properties. Electric fields can modify phase transformations by their enhancement of atomic diffusivity, as, for example, their influence on diffusion-controlled transformations such as eutectoidal decomposition of steel or age hardening of aluminum alloys. Electric fields can also bias phase transformations toward phases which have higher dielectric constants than the parent phase. Much more research is needed to fully exploit magnetic/electric fields as another tool to control structure, and therefore properties of materials. (C) 2000 Elsevier Science S.A. All rights reserved.