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.
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
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.
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.