科研之友
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摘要
Newly discovered micro and nanoscale cold welding has already exhibited great potential in up-to-date nanofabrication processes. In this paper, the atomistic-scale pressure welding processes for metallic nanowires (NWs) are studied using embedded-atom molecular dynamics (MD) simulations. The mechanical behavior and structural evolution of the metallic nanowires, including Au, Ag, and Cu materials that experienced a mechanical stretching break and solid-phase pressure welding process, were thoroughly investigated. The welding temperatures (T (w)) ranging from 100 to 900 K were systemically examined for the effects of welding strength. The ratio of welding strength, R (ws), defined as the ratio between the welding strength and the original yield strength of NWs, was employed to identify the welding quality. Simulation results show that the R (ws) of Au NWs is better than those of Ag and Cu welded at room temperature; however, for welding at high temperatures (600-900 K), the R (ws) value of Ag NWs is the best. The R (ws) values of Au NWs using cold welding show less variance than with high temperature welding, reflecting that the application of cold welding on the Au NWs is highly feasible. The R (ws) values for NWs with small diameters are generally higher than those with large diameters. The breaking places of the tensile test for the post-welded NWs did not occur at the welding region, indicating that the broken wires can be robustly reconnected through solid-phase mechanically-assisted welding devices.
- 出版日期2012-11
