新型纳米结构金属材料的力学性能及变形机制

Mechanical behaviors and deformation mechanisms of novel nano-structured metals

"纳米结构"化是金属及其合金材料获得优异力学性能的有效途径.纳米结构金属材料表面或内部的缺陷,包括晶界、位错、孪晶、孔洞、裂纹、第二相等,其形核、演化及互相作用对材料的强度和韧性具有重要影响.该文综述了与上述科学问题相关的新型纳米结构金属材料的微观组织结构表征及力学性能测试、强韧化机制计算模拟方面的研究进展.并讨论了急需从微观尺度上就新型纳米结构金属材料的特征力学行为和关键变形机制开展深入、系统研究.

Nano-structured metals and their alloys possess superior mechanical properties. The defects inside or on the surfaces of the nano-structured metals, including grain boundaries, dislocations, twin boundaries, voids, cracks, the second phases, etc., can influence the materials strength and toughness significantly through their nucleation, evolution and interactions. This review article surveys the advances in microstructure characterization and mechanical testing, as well as computations and simulations on strengthening and toughening mechanisms of several novel nano-structured metals. It is also proposed that the comprehensive investigation is necessary on nano-structured metals to obtain the specific mechanical behaviors and primary deformation mechanisms at atomic scales.