Influence of equal channel angular pressing on high cycle fatigue behavior of ultrafine-grained iron: Role of anisotropy
Influence of equal channel angular pressing on high cycle fatigue behavior of ultrafine-grained iron: Role of anisotropy
复制标题
DOI：
10.1016/j.msea.2017.11.075
复制
发表时间：
2018-01
期刊：
影响因子：
6.4
通讯作者：
E. Bruder;Chandanraj Gangaraju;R. Lapovok
中科院分区：
文献类型：
--
作者：
E. Bruder;Chandanraj Gangaraju;R. Lapovok
研究了通过等通道转角挤压（ECAP）加工的ARMCO®铁的路线A和路线BC的高周疲劳行为，这分别导致具有高和低晶粒伸长率的超细晶粒显微组织。沿沿着两个不同测试方向的旋转弯曲疲劳测试表明，尽管路径A产生了更高的晶粒伸长率和更强的晶体学织构，路径BC的疲劳强度具有显著的各向异性，但路径A的疲劳强度仅存在微小差异。尽管如此，通过路线A处理的样品的表面处的疲劳损伤是高度各向异性的，因为它被限制在具有相对于表面平面的微结构伸长平面的一定对准的区域。在高周疲劳强度的各向异性的路线BCas和表面取向依赖的抗疲劳损伤的路线A的剪切平面的对齐方面进行了讨论，在最后ECAP通过和显微组织形态和亚晶粒粗化，导致疲劳裂纹萌生之间的相关性。
The high cycle fatigue behavior of ARMCO® Iron processed by equal-channel angular pressing (ECAP) was investigated for routes A and BC, which results in ultrafine-grained microstructures with high and low grain elongations, respectively. Rotating bending fatigue tests along two different testing directions show a significant anisotropy in the fatigue strength for route BCbut only marginal differences for route A, in spite of the higher grain elongation and stronger crystallographic texture that is generated by route A. Still, the fatigue damage at the surface of samples processed by route A is highly anisotropic, as it is confined to regions with a certain alignment of the microstructural elongation plane with regard to the surface plane. The anisotropy in high cycle fatigue strength for route BCas well as the surface orientation dependent resistance to fatigue damage for route A are discussed with regard to the alignment of the shear plane during the last ECAP pass and the correlation between the microstructural morphology and subgrain coarsening that lead to fatigue crack initiation.