Dynamic recovery in nanocrystalline Ni. (1st June 2015)

• Record Type: Journal Article
• Authors: Sun, Z.; Van Petegem, S.; Cervellino, A.; Durst, K.; Blum, W.; Van Swygenhoven, H.
• Is Part Of: Acta materialia. Volume 91(2015)
• Page Start: 91
• Page End: 100
• Publication Date: 2015-06-01
• Subjects: Stress reduction -- X-ray diffraction -- Recovery by GB accommodation -- Quasi-stationary state -- Constant flow stress; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2015.03.033
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: The constant flow stress reached during uniaxial deformation of electrodeposited nanocrystalline Ni reflects a quasi-stationary balance between dislocation slip and grain boundary (GB) accommodation mechanisms. Stress reduction tests allow to suppress dislocation slip and bring recovery mechanisms into the foreground. When combined with in situ X-ray diffraction it can be shown that grain boundary recovery mechanisms play an important role in producing plastic strain while hardening the microstructure. This result has a significant consequence for the parameters of thermally activated glide of dislocations, such as athermal stress and activation volume, which are traditionally derived from stress/strain rate change tests.