High strength, epitaxial nanotwinned Ag films

In situ nanoindentation study on plasticity and work hardening in aluminium with incoherent twin boundaries

“…Plastic deformation mechanisms have been intensively studied in nt metals with face-centered cubic structure. The majority of prior studies focused on metals with low stacking-fault energy (SFE) (Cu, Ag) and/or a low ratio of unstable twinning (g ut ) to unstable stacking energy (g us ), because twins readily form in such metals during growth or deformation [10][11][12][13] . Although the density of incoherent twin boundaries (ITBs) is typically lower than that of CTBs, both CTBs and ITBs have been found to play crucial roles in plastic deformation in nt metallic materials with low SFE; CTBs act as barriers for slip, but ITBs can easily migrate in association with detwinning 14,15 .…”

Twinning effects on strength and plasticity of metallic materials

“…25 By using different substrates, inclined growth twins have been synthesized in sputtered epitaxial NT Ag (110) fi lms on a Si (110) substrate with ∼ 40 nm average twin spacing ( Figure 1b ). 20 By comparison, the average twin thickness in sputtered NT Ag (111) fi lms is ∼ 10 nm at the same deposition rate and temperature. 20 The average twin spacing can also be tailored by controlling the orientation of growth twins by sputtering.…”

“…20 By comparison, the average twin thickness in sputtered NT Ag (111) fi lms is ∼ 10 nm at the same deposition rate and temperature. 20 The average twin spacing can also be tailored by controlling the orientation of growth twins by sputtering. Extending the applicability of NT microstructures to metals with high stacking-fault energy (SFE) or non-face-centered-cubic (fcc) structures remains a challenge, as it is energetically more diffi cult to introduce TBs in these materials.…”

“…82 A recent study of NT Ag shows that texture can also tailor the formation of twins. 20 Besides good thermal stability, certain NT metals (such as Cu) also have high electrical conductivity and high strength ( Figure 5b ). 8 , 14 , 16 , 83 -90 The electron scattering coeffi cient at CTBs is an order of magnitude lower than that at GBs; CTBs provide a unique way of enhancing strength with little loss of electrical conductivity.…”

On the mechanical performance and deformation of nanotwinned Ag

“…3 In fact, both simulations and experimental studies have reported that NT-Ag might be more optimal in terms of its mechanical performance, as compared to NT-Cu. [3][4][5] However, thus far, experimental results for NT-Ag have been limited to indentation data and have mostly been focused on strengthening effects as a function of twin spacing.…”