Mechanical Properties of Nanocrystalline Materials
Mechanical Properties of Nanocrystalline Materials
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DOI：
10.1002/9783527674947.ch1
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发表时间：
2015-07
影响因子：
2.9
通讯作者：
P. Cavaliere
中科院分区：
文献类型：
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作者：
P. Cavaliere
本章介绍了纳米结构金属和合金的机械性能的增加，通过增加晶粒细化到一个水平，在这个水平上，晶粒尺寸体积开始影响位错的产生和运动，导致在这样的行为反转，众所周知的Hall-Petch反转。纳米结构材料的微观结构和力学特性在很大程度上取决于生产技术。材料的疲劳性能很大程度上取决于晶粒尺寸的变化。许多实验证据可以在超细和纳米晶（NC）制度。一般来说，通过等通道转角挤压（ECAP）实现的晶粒细化可提高应力控制试验中的疲劳性能。随着晶粒尺寸的减小，疲劳裂纹扩展速率加快的主要机制是随着晶粒细化，裂纹路径偏转减少。
This chapter describes the increase in the mechanical properties of nanostructured metals and alloys by increasing the grain refinement up to a level at which the grain size volume begins influencing the dislocation generation and motion, leading to an inversion in such a behavior, well known asHall–Petch inversion. The microstructural and mechanical features of nanostructured materials strongly depend on the production techniques. The fatigue properties of materials are strongly governed by the grain size variation. Many experimental evidences can be presented both in the ultrafine and in the nanocrystalline (NC) regime. In general, grain refinement via equal‐channel angular pressing (ECAP) leads to an increase in fatigue properties in stress‐controlled tests. The primary mechanism responsible for the accelerated fatigue crack growth rate observed with decreasing grain size is the reduction in crack path deflection with grain refinement.