纳米孪晶金属材料.pdf

46 11 2010 11 1422—1427 ACTA METALLURGICA SINICA Nov. 2010 –1427 ?( ( ) , 110016) , , , . . , ( ) ( ), . , , , , TG146 A 0412 ?1961(2010)11 ? 1422 ? 06 METALLIC MATERIALS WITH NANO–SCALE TWINS LU Lei, LU Ke Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 Correspondent: LU Lei, professor, Tel: (024)23971939 , E-mail:******@imr. Supported by National Natural Science Foundation of China (Nos. 50725103 , 50890171 and 51071153 )and National Basic Research Program of China (No. 2005CB623604 ) Manuscript received 2010–09–09 ABSTRACT Strengthening materials is a central objective of materials research. Traditional approaches to strengthen materials, including solid solution strengthening, second phase strengthening, grain re?nement strengthening, dispersion strengthening and work hardening strengthening etc ., aimat creation of internal defects and boundaries so as to obstruct the motion of dislocations. Such strategies for strengthening promise the ductility and electrical conductivity of the material. By reviewing recent advances in our understanding of nanostructured metals and alloys, we propose a novel approach to optimize the strength, ductility and the electrical conductivity of materials by means of coherent twin boundaries at nano–meter scale. We assess current understanding of stre