Cyclic deformation and fatigue properties of very fine-grained metals and alloys

The Cyclic Deformation Behavior of Severe Plastic Deformation (SPD) Metals and the Influential Factors

“…In the case of high purity copper, the grain coarsening phenomenon discussed above has been specifically detected to be related to the shear bands, regardless of the fact that these bands were formed during material processing or during cyclic deformation, in ARBed pure copper [56,57]. In addition to all the aforementioned micro-activities on the materials' response in cyclic deformation, as Mughrabi and Höppel further pointed out the purity of the metal, the cyclic loading mode, and the processing parameters all have clear effects on the resulting cyclic deformation responses [64]. A similar statement could be made from the current review, where the underlying factors that influence the cyclic deformation of SPDed metals will be discussed in the subsequent sections.…”

Introduction

“…The mechanical properties and fatigue behavior of ultrafinegrained metals became a most important research topic in Mughrabi's later years before retirement which resulted in a quite comprehensive understanding of the fatigue properties based on the very basic concepts of Morrow, Manson-Coffin and Basquin. 6 Also the field of high temperature materials has seen some important developments in the last years. For example TiAl alloys have made it now into application in aero engines and new c/c9 strengthened superalloys based on Co are very interesting emerging new materials.…”

Mechanical Properties of Copper Processed by Severe Plastic Deformation

“…From the recent overview of the cyclic deformation and fatigue properties of UFG materials by Mughrabi & Höppel (2010) it arises that the fatigue behaviour depends strongly on parameters of the ECAP procedure, purity of material and type of fatigue loading. The discussion, interpretation and, in particular, the comparison of results published in literature, requires all the details of the UFG structures produced in different laboratories and also the external loading parameters and conditions to be taken into account.…”

“…This result seems to be obvious, because the UFG Cu is harder but less ductile than CG Cu. Based on these facts, Mughrabi and Höppel (2010) explain it schematically on the total strain life diagrams of UFG and CG materials.…”