2 research outputs found
On the solution of some diffusion equations with concentration-dependent diffusion coefficients-II
On the basis of further analytical results an improved algorithm for the numerical solution of a non-linear differential system arising from some diffusion systems with concentration-dependent diffusion coefficients is presented. In comparison with the previously reported approach the present method does not require the solution of an approximate equation and is simpler and more effective in its iteration processes. An example of numerical solutions of a diffusion system from the investigation of protons diffusion is demonstrated
Role of Graphene in Reducing Fatigue Damage in Cu/Gr Nanolayered Composite
Nanoscale
metal/graphene nanolayered composite is known to have ultrahigh
strength as the graphene effectively blocks dislocations from penetrating
through the metal/graphene interface. The same graphene interface,
which has a strong sp2 bonding, can simultaneously serve as an effective
interface for deflecting the fatigue cracks that are generated under
cyclic bendings. In this study, Cu/Gr composite with repeat layer
spacing of 100 nm was tested for bending fatigue at 1.6% and 3.1%
strain up to 1,000,000 cycles that showed for the first time a 5–6
times enhancement in fatigue resistance compared to the conventional
Cu thin film. Fatigue cracks that are generated within the Cu layer
were stopped by the graphene interface, which are evidenced by cross-sectional
scanning electron microscopy and transmission electron microscopy
images. Molecular dynamics simulations for uniaxial tension of Cu/Gr
showed limited accumulation of dislocations at the film/substrate
interface, which makes the fatigue crack formation and propagation
through thickness of the film difficult in this materials system