This paper analyses slip transfer at the boundary of nanoscaled growth twins in face-centred cubic (f.c.c.) metals for strengthening mechanism. The required stress for slip transfer, i.e. inter-twin flow stress, is obtained in a simple expression in terms of stacking fault energy and/or twin boundary (TB) energy, constriction energy and activation volume. For nanotwinned Al, Cu and Ni, inter-tw...

In this study, a comprehensive investigation on nano-scale machining of polycrystalline copper structures is carried out by molecular dynamics (MD) simulation. Simulation cases are constructed to study the impacts of grain size, as well as various machining parameters. Six polycrystalline copper structures are produced, which have the corresponding equivalent grain sizes of 5.32, 6.70, 8.44, 13...

Abstract The strength of polycrystal increases as the grain diameter l decreases, i.e. Hall–Petch behaviour. This trend reverses at about 3 < 15 nm, inverse-Hall–Petch How size affects material’s nm (~12 particles) remains unclear. Here our simulations use mixtures soft and hard particles so that compression can continuously reduce to merely a few particles, resulting in ultrafine-grained so...

Abstract A review presents the results of current studies wood’s hierarchical structure using modern physical means on nano- to macro scales. Relationships between and mechanical properties at these levels are discussed. It is shown that size effects in wood strength obey Hall–Petch relationship a range around six orders magnitude structural unit characteristic sizes.

The elastic and vibrational properties of iron-nickel and aluminum nanoparticles and nanocrystalline materials have been investigated on the basis of molecular dynamics simulations and the embedded atom method for the description of the materials. It is well known that nanocrystalline solids, with grain sizes in the nanometer range, exhibit often unsual properties like increased hardness due to...

The plane-strain bulge test is used to investigate the mechanical behavior of freestanding electroplated Cu thin films as a function of film thickness and microstructure. The stiffness of the films increases slightly with decreasing film thickness because of changes in the crystallographic texture and the elastic anisotropy of Cu. Experimental stiffness values agree well with values derived fro...

Understanding the grain size-dependent failure behavior of polycrystalline graphene is important for its applications both structurally and functionally. Here we perform molecular dynamics simulations to study the failure behavior of polycrystalline graphene by varying both grain size and distribution. We show that polycrystalline graphene fails in a brittle mode and grain boundary junctions se...