Abstract This paper gives an overview of ‘‘Grain boundary engineering (GBE)for advanced materials by magnetic ?eld application’’based on recent exper-imental work performed on different kinds of struc-tural and functional materials.It is shown that magnetic ?eld application has a great potential and unique advantage as ‘‘non-contact processing’’for microstructure control,irreplaceable by any other existing processing methods.The control of grain growth and texture by magnetic ?elds has been found to be generally applicable to many metallic materials,irrespective of whether they are ferromagnetic or not.Grain growth which is controlled by grain boundary migration was found to be strongly affected by mag-netic ?eld application.Recent attempts at the grain boundary engineering by magnetic ?eld application through phase transformation have revealed that magnetic phase transformation can provide us a new approach to grain boundary engineering for iron alloys and steels,as well as a new nanocrystalline material produced by magnetic crystallization from the amor-phous state.The possibility of engineering applications

of enhanced densi?cation using magnetic sintering and magnetic rejuvenation has been discussed for iron powder compacts and deformation-damaged iron al-loys,respectively.

Introduction

It is our great pleasure to present an overview paper of ‘‘grain boundary engineering for advanced materials by magnetic ?eld application’’,at the Brandon sym-posium in honor of Prof.David Brandon who was one of the pioneers of grain boundary research and has been leading this ?eld since the time of 1960’s.We have greatly bene?ted from his work and are now collecting the fruits of the scienti?c activities of many pioneers who were deeply involved in this ?eld.According to the discipline of ‘‘Materials Science and Engineering’’,the control of the microstructure by well-designed processing under optimum condition is a key issue of design and development of high perfor-mance engineering materials.In particular,the control of the grain boundary microstructure is essential in the development of high performance polycrystalline structural or functional materials,because structure-dependent grain boundary properties are known to control almost all bulk properties of polycrystalline materials.Extensive studies have been made on the grain boundary structure and properties in metals,semiconductors,and more recently ceramics,from the 1960’s up to now [1–8].It is well known that grain boundary properties strongly depend on the character and structure of the grain boundary.High-energy

T.Watanabe ?S.Tsurekawa

Department of Nanomechanics,Graduate School of Engineering,Tohoku University,Sendai,Japan

X.Zhao ?L.Zuo ?T.Watanabe (&)

Key Laboratory of Electromagnetic Processing of Materials (EPM),Northeastern University,Shenyang 110004,China e-mail:[email protected]

C.Esling

LETAM,CNRS-UMR 7078,University of Metz,Metz Cedex 0157045,France

J Mater Sci (2006)41:7747–7759DOI 10.1007/s10853-006-0740-1

A new challenge:grain boundary engineering for advanced materials by magnetic ?eld application

Tadao Watanabe ?Sadahiro Tsurekawa ?Xiang Zhao ?Liang Zuo ?Claude Esling

Received:4April 2006/Accepted:28July 2006/Published online:24October 2006óSpringer Science+Business Media,LLC 2006