Multiscale Phenomena in Fatigue of Ultra-Fine Grain Materials-an Overview
Multiscale Phenomena in Fatigue of Ultra-Fine Grain Materials-an Overview
复制标题
DOI：
10.2320/matertrans.42.74
复制
发表时间：
2001-01
影响因子：
1.2
通讯作者：
A. Vinogradov;S. Hashimoto
中科院分区：
文献类型：
--
作者：
A. Vinogradov;S. Hashimoto
结合近年来的试验结果和常见的疲劳概念，综述了超细晶粒材料在剧烈塑性变形作用下的循环变形。采用等通道角挤压（ECAP）技术，获得了特征结构单元尺寸为200 ~ 300 nm的高强度大块金属。从应力控制疲劳和应变控制疲劳两方面讨论了材料的疲劳特性。强调恒应力幅值下疲劳寿命的提高，而恒塑性应变幅值下疲劳寿命的缩短。在不同尺度上表征了疲劳后材料的精细结构和表面形貌，以解释所观察到的疲劳行为。在简单的位错动力学单参数模型框架内讨论了eca加工材料的疲劳机理。
Cyclic deformation of ultra-fine grain (UFG) materials processed by severe plastic deformation is reviewed in light of recent experimental results and common concepts of fatigue. High strength bulk metals with a characteristic structural element size of 200–300 nm were obtained through the so-called equal-channel angular pressing (ECAP) technology. Fatigue properties are discussed in terms of stress-controlled and strain-controlled fatigue. Enhancement of fatigue life under constant stress amplitude is emphasized in comparison with some shortening in fatigue life under constant plastic strain amplitude. Fine structure and surface morphology of post-fatigued materials are characterized on different scale levels to account for the fatigue behaviour observed. Mechanisms of fatigue in ECA-processed materials are discussed within frameworks of a simple one-parameter model of dislocation kinetics.