Recent Progress in Magnetic Field Applied Grain Boundary Engineering

摘要

Properties and performance of polycrystalline materials are remarkably affected by grain boundary microstructure. Many studies on grain boundary structure and properties have been made since 1950s and evidenced that mechanical and functional properties of individual grain boundaries depend on the grain boundary character and structure. Grain boundary engineering, whose concept was first proposed by T, Watanabe in early 1980s 1), is rapidly emerging recently as a powerful tool achieving enhanced property and performance of polycrystalline materials 2-6). For further innovation, external potential fields like a magnetic field are applicable to grain boundary/interface engineering as a new materials processing. Since Smoluchowski and Turner 7) first reported in 1949 that a magnetic field could enhance the development of [110](001) texture in an Fe-35 percent Co alloy, it has been revealed that a magnetic field can affect many metallurgical phenomena such as recrystallization 8-10), grain boundary migration 11-14), grain growth 15, 16), precipitation 17, 18) and phase transformation 19, 20). In this talk, an overview of recent progress in magnetic field applied grain boundary engineering will be made. In particular, we will highlight (1) the control of grain boundary segregation and segregation-induced brittleness in Fe-Sn alloy, (2) magnetic crystallization of Fe-Si-B alloy from amorphous phase and (3) diffusion in a magnetic field.