Loading...

Evaluation of the role of deformation twinning in work hardening behavior of face-centered-cubic polycrystals

Hamdi, F ; Sharif University of Technology | 2008

410 Viewed
  1. Type of Document: Article
  2. DOI: 10.1007/s11661-007-9356-6
  3. Publisher: 2008
  4. Abstract:
  5. Results of an investigation on the evolution of microstructure during simple compression testing of two face-centered-cubic (fcc) polycrystals, IN625 superalloy and 316L stainless steel, are reported and a review on the existing data related to the uniaxial deformation of fcc polycrystals is presented. It is found that while a number of fcc polycrystals show linear hardening behavior, the evolution of the underlying microstructure may be quite different. It is argued that, in contrast to the current belief, deformation twinning may not be the sole cause of linear hardening in low stacking fault energy (SFE) fcc polycrystals. It is suggested that, due to the requirement of slip system change prior to twinning, only fcc crystals with sufficiently low twinning stress are expected to form mechanical twins after a certain amount of initial plastic strain. In other fcc polycrystals that show linear hardening behavior competitive mechanisms, such as formation of Lomer-Cottrell (LC) locks may be dominant hardening mechanism. The effectiveness of these slip barriers in fcc polycrystals is expected to increase with the tendency of the material to slip planarity. Therefore, parameters such as SFE, temperature, Peierls stress, and short range ordering (SRO) are expected to have a contribution to the linear hardening response of fcc polycrystals. This proposal appears to offer a more comprehensive explanation for a wide range of experimental data presented in the scientific literature. © The Minerals, Metals amp; Materials Society and ASM International 2007
  6. Keywords:
  7. Compression testing ; Hardening ; Microstructural evolution ; Nickel alloys ; Plastic deformation ; Stacking faults ; Stainless steel ; Superalloys ; Twinning ; Face-centered-cubic polycrystal ; Short range ordering ; Stacking fault energy ; Uniaxial deformation ; Polycrystals
  8. Source: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 39, Issue 2 , 2008 , Pages 294-303 ; 10735623 (ISSN)
  9. URL: https://link.springer.com/article/10.1007/s11661-007-9356-6