Molecular Dynamics Studies in Nanojoining: Self-Propagating Reaction in Ni/Al Nanocomposites

Reactive joining with Ni/Al nanocomposites is an innovative technology that provides an alternative to more common bonding techniques. This work focuses on a class of energetic material, produced by high energy ball milling and cold rolling. The initial microstructure is more complex than that of reactive multilayer nanofoils, produced by magnetron sputtering, in which the bilayer thickness is constant. Typical samples are composed of reactive nanocomposite particles that are numerically modelized by randomly distributed layered grains. The self-propagating reaction was studied by means of molecular dynamics simulations. We determined the front characteristics and investigated the elemental mechanics that trigger propagation. Both dissolution of Ni in amorphous Al and sustained crystallization of the B2-NiAl intermetallic compound were found to contribute to the heat delivered during the process.

Automated summary

This study focuses on reactive joining with Ni/Al nanocomposites produced by high energy ball milling and cold rolling. Molecular dynamics simulations were used to study the self-propagating reaction and investigate the elemental mechanics triggering propagation, finding that the dissolution of Ni in amorphous Al and the sustained crystallization of the B2-NiAl intermetallic compound contribute to the heat delivered during the process.