Molecular Dynamics Simulations of Deformation Mechanisms in the Mechanical Response of Nanoporous Gold

Abstract

The mechanical behaviour of nanoporous gold has so far been the subject of studies for bicontinuous morphologies, while the load transfer between ligaments is the primary challenge for using nanoporous structures—especially membranes with nanopores—in single-molecule sensors. This work studies the pore shape effect on deformation mechanisms of nanoporous gold membranes through molecular dynamics simulations. Tension and compression tests are carried out for nanoporous gold with circular, elliptical, square and hexagonal pore shapes. A significant pore shape effect on the mechanical properties is observed with distinct load transfer capabilities. A uniform stress transfer between ligaments constitutes a distinguished set of mechanical responses for structures with the hexagonal pore shape under tension, while a unique stress distribution in nanoporous with the circular pore shape introduces a high strength and ductile structure under compression. Further to shed light on the existing experimental observations, this work provides a comprehensive study on load transfer capabilities in the mechanical behaviour of nanoporous gold for sensing applications.

Study of Nonlinear Deformation of FCC‐AuCuSi under Pressure by the Statistical Moment Method

“…We apply theoretical results to alloy AuCuSi. e maximum real stress σ 1 max and the elastic limit σ e calculated by the SMM are in good agreement with MD results [16] and experiments [13,14]. For AuCuSi at the same temperature, concentration of substitutional atoms, and concentration of interstitial atoms, when the pressure increases, the maximum real stress increases and the elastic limit decreases.…”

“…e maximum real stress σ 1 max and the elastic limit σ e calculated by the SMM in Table 3 are in good agreement with the molecular dynamics (MD) results [16] and experiments [13,14]. e error of the maximum real stress between the SMM calculation and the MD result [16] is 0.6%. e error of the elastic limit between the SMM calculation and the experimental data [13] is 5.65%.…”

“…Figure 2 shows the curve of real stress σ 1 (ε) for Au at P � 0 and T � 300 K where we have the comparison between the SMM and experiments [11,12]. e maximum real stress σ 1 max and the elastic limit σ e calculated by the SMM in Table 3 are in good agreement with the molecular dynamics (MD) results [16] and experiments [13,14]. e error of the maximum real stress between the SMM calculation and the MD result [16] is 0.6%.…”

“…Numerical calculations for many metals are compared with ab initio calculations and experiments. Deformation mechanisms in the mechanical response of nanoporous gold are investigated by molecular dynamics simulations [16]. In addition, in recent years, some researchers have considered factors affecting the structure, the phase transformation, and the crystallization process of alloys AuCu [17], NiCu [18,19], and AgCu [20].…”

“…Values of ε F (f (ε F ) � f max ), σ 1max , ε e , and σ e for Au at P � 0 and T � 300 K calculated by the SMM and from MD[16], EXPT [13], and EXPT[14].…”