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...

The process of nanocontact including indentation and retraction between a large Ni tip and a Cu substrate is investigated using quasicontinuum (QC) method. The multiscale model reveals that significant plastic deformation occurs during the process of nanocontact between Ni tip and Cu substrate. Plastic deformation is observed in an area as large as 20 nm wide and 10 nm thick beneath Ni tip duri...

Copper monocrystals were subjected to shock compression at pressures of 10-60 GPa by a short (3 ns initial) duration laser pulse. Transmission electron microscopy revealed features consistent with previous observations of shock-compressed copper, albeit at pulse durations in the us regime. The results suggest that the defect structure is generated at the shock front. A mechanism for dislocation...

The problem: A new type of steel is known as Twining Induced Plasticity Steel, more commonly known as TWIP Steel. There is a general interest in using this type of steel in the automotive industry due to its unique material properties such as super toughness and super ductility, although its chemical properties also play a vital role. It has a high content of Mn (more than 25%) and about 3% Si ...

The strength-ductility trade-off has been a long-standing dilemma in materials science. This has limited the potential of many structural materials, steels in particular. Here we report a way of enhancing the strength of twinning-induced plasticity steel at no ductility trade-off. After applying torsion to cylindrical twinning-induced plasticity steel samples to generate a gradient nanotwinned ...

Abstract Modeling deformation twin nucleation in magnesium has proven to be a challenging task. In particular, the absence of heterogeneous model which provides accurate energetic descriptions for twin-related structures indicates need more deeply understand energetics. To address this problem, molecular dynamics simulations are performed follow evolution <mml:ma...

We employ classical molecular dynamics to calculate elastic properties and to model the nucleation and propagation of deformation twins in calcite, both as a pure crystal and with magnesium and aspartate inclusions. The twinning is induced by applying uniaxial strain to the crystal and relaxing all stress components except the uniaxial component. A detailed analysis of the atomistic processes r...

Twinning induced plasticity (TWIP) steels with high manganese percentage (17-35%), are mostly used in automotive bodies. Their microstructure at room temperature is austenitic, and due to the low stacking fault energy, major deformation mechanism in them is twinning inside austenite grains which leads to enhanced mechanical strength in the steel. Due to the important effect of heat treatment pr...

Large-strain monotonic and cyclic loading tests of AZ31B magnesium alloy sheets were performed with a newly developed testing system, at different temperatures, ranging from room temperature to 250 °C. Behaviors showing significant twinning during initial in-plane compression and untwinning in subsequent tension at and slightly above room temperature were recorded. Strong yielding asymmetry and...