Effects of interface sliding on the formation of telephone cord buckles

Abstract

Sliding at interface during thin film buckling was reported by recent atomistic simulations. A stability analysis under the Föppl-von Kármán plate theory is performed to investigate the effect of interface sliding on the transition of a straight-sided blister to the telephone cord buckle in biaxially compressed thin films on rigid substrates. It is shown that the critical stress and the wavelength of the telephone cord buckle significantly increase as the interface sliding is noticeable in comparison with the constant values derived from previous classic analysis without interface sliding. Our theoretic analysis is further validated by results from numerical simulations based on our recently developed continuum model of nonlinear buckling. The results indicate that the wavelength variation in the telephone cord buckle observed in experiments may be due to interface sliding.

The shape of telephone cord blisters

“…8), we believe that the waviness period of the TC blister may be inherited from the instability wavelength. The deviation from λ / b ≈2 is attributed that λ / b also depends on the adhesion with a non-trivial relationship1416. Usually the increase of A / λ releases more the elastic energy in the biaxially compressed film deposited on the substrate, while it has to increase the mixed-mode-dependent adhesion energy.…”

“…In addition, the ratio may be not constant and change with the interfacial adhesion and the film-to-substrate modulus ratio111213141516. The zigzag undulation feature of the TC buckle has been replicated by numerical investigations51516171819.…”

“…Further, it has been found that the TC blister can also grow with the appearance of sags by an oscillatory process and its edge unnecessarily starts straight1011. So far, a convincing solution for the three-dimensional (3D) TC blister morphology remains a challenge because of limited methods for handling nonlinear elasticity of thin plate, although a series of numerical models and experiments have provided valuable insights into the morphological features of TC blisters10111213141516171819202122232425.…”

The effect of interface adhesion on buckling and cracking of hard thin films

“…17 It has also been demonstrated that the height and width of the buckles are related to the properties of the cohesive zone in both FEM simulations 18,19 and atomistic simulations. 16,20 Scanning electron microscopy (SEM) images of a Ti 0.39 Si 0.04 N 0.57 thin film grown on a silicon substrate using DC reactive magnetron sputtering 4 showed that various buckling patterns were generated including circular blisters, straight-sided wrinkles and telephone cords with widths or diameters in the range of 15-25 µm. Moreover, most of the buckling patterns exhibited cracks at their apexes and/or at the bottom of the buckle (Fig.…”

“…10,[12][13][14][15] This approach is valid when the interface strength is infinite at the delamination front. 14,16 It has been shown that by taking into account interface adhesion using a cohesive zone model, the kinematics of a propagating telephone cord buckle can be simulated. 17 It has also been demonstrated that the height and width of the buckles are related to the properties of the cohesive zone in both FEM simulations 18,19 and atomistic simulations.…”