Capillary instability of a cylindrical jet with an elastic shroud: A model for the breakup of an oxidized metal jet

Stability of an inviscid axisymmetric jet of uniform surface tension and flexural rigidity is investigated. It is shown that for large enough values of flexural rigidity the capillary instabilities are suppressed. The result corroborates the observed stabilization and possible non-breakup of solder jets in the presence of atmospheric oxygen, which causes the appearance of a layer of oxides on the interface. The work is timely because of its direct relevance to a host of emerging technologies exemplified by solder jetting in the manufacturing of microelectronic components.