Twinning dislocation multiplication at a coherent twin boundary

The dual role of coherent twin boundaries in hydrogen embrittlement

“…In the case of CTBs, such sliding may occur by dislocation glide along the GB plane, that is, by the conventional dislocation-based mechanism of plastic deformation [28][29][30][31] . Dislocation-mediated GB sliding is possible at CTBs because the GB plane of a CTB is a {111} plane, that is, a glide plane for dislocations in FCC metals 32 .…”

Twinning and De-twinning via Glide and Climb of Twinning Dislocations along Serrated Coherent Twin Boundaries in Hexagonal-close-packed Metals

“…Email: wangj6@lanl.gov an array of grain boundary dislocations (GBDs) [18]. However, even GBs with misorientation near an ideal twin misorientation may not be symmetric due to the GBmediated plastic deformation and slip activity [15][16][17][18][19][20]. Accompanying the growth of a twin, slips are often activated.…”

Twinning effects on strength and plasticity of metallic materials

“…36 Alternatively, dislocations can interact with {111} CTBs, causing the multiplication of dislocations at TBs. 37 The stress for migration of ITBs in NT Cu is very low, ∼ 100 MPa, which is much lower than the yield strength of NT Cu. 32 , 56 The same technique also reveals substantial work hardening in NT Ni due to the formation of sessile dislocations at CTBs, where the CTBs effectively block the transmission of dislocations.…”

“…35 N. Li et al reported the pinning of mobile ITBs due to residual dislocations that were produced by transmission of glide dislocations across an ITB in Cu, 36 and the formation of steps at CTBs due to dislocation-CTB interactions ( Figure 2b ). 37 Bufford et al explored work hardening due to ITBs in NT Al ( Figure 2c ). 38 Experiments showed that smaller twin spacing leads to greater strength, higher strain-rate sensitivity, enhanced work-hardening rate, and higher density of mobile dislocations at TBs in NT metals.…”

“…51 Using in situ transmission electron microscopy (TEM) and MD simulations, N. Li et al identifi ed a novel dislocation multiplication mechanism when a mixed dislocation interacts with CTBs in Cu ( Figure 2b ), leading to steps with thicknesses of several atomic layers on the CTB. 37 The softening in electrodeposited NT Cu has been ascribed to abundant sources for dislocation nucleation when the twin spacing reduces to several nm. 41 For NT metallic nanowires, Sansoz et al showed that strain softening occurs in metals with medium-to-high SFE, such as Al, whereas considerable work hardening occurs in metals with lower SFE (e.g., Ag and Au).…”