Gaseous metal uses to consist of individual neutral atoms ("uses to" because there must be some exceptions). So when a metal sublimates or evaporates, ions separate from the metal together with the proper number of electrons to be neutral.
Deforming a metal doesn't need to break any bond... but it does need to pass some ions by others, which is difficult. In fact, deformation never happens with a force that cleaves the crystal and moves an ion plane versus an other.
First, temperature does most work; the force only makes the deformation happen preferentially in one direction, while temperature alone would do it randomly and symmetrically.
Then, deformation happens at special sites in the crystal that have already a stacking fault, called a dislocation. At the pre-existing dislocation, an atom has neighbours at imperfect positions, and this imperfection can travel easily - much more easily than a perfect stacking.
http://en.wikipedia.org/wiki/DislocationMetallurgy is badly complicated - so much that it can explain anything and its opposite equally well, to my opinion - but often, pure metals are very soft; alloying them is generally said to hinder the movements of dislocations, and this makes alloys harder.