Quasi-continuum Simulations Solid-state Pressure Nanowelding of Metals 
C. D. Wu and T. H. Fang and Y. J. Lin
Current Nanoscience, 14, 179-186 (2018).

ABSTRACT
Background: Nanowelding is an attractive bottom-up fabrication technique that
allows the construction, connection, and repair of nanomaterials. The effects of
contact interference, crystal orientation, and material type of nanoscale welded
pairs are investigated in terms of atomic trajectories, strain distribution, and
the stress-strain curve.& para;& para;Methods: The quasi-continuum (QC) method
is applied to simulate nanowelding process. The QC method is a multi-scale
combined molecular dynamics approach that mixes atomistic and continuum
algorithms.& para;& para;Results: At a small contact interference of 0-1 nm, the
ultimate stress of welded pairs is independent of the magnitude of contact
interference. Regarding the effect of material type, the average ultimate stress
for Ni-Ni welded pairs is the highest and that for Cu-Cu welded pairs is the
lowest, regardless of the contact orientation mode. The elongation of Ni-Ni
welded pairs increases with increasing contact interference.& para;&
para;Conclusion: The crystal orientation of the contact plane and material type
significantly determine the welding quality. Welding on the close-packed plane
of both substrates leads to the highest ultimate stress. The ultimate stress for
Ni-Ni welding pairs is the highest, and that for Cu-Cu welded pairs is the
lowest.