How to have deformation/denting of 2D objects on impact?

How can I have objects become dented and deformed on impact with each other. For example two spaceships crashing into each other, with one tearing through the other leaving both dented and one in two halves?

For the two halves, you could use a custom slice when you set up your Sprite then animate the two halves. (Or even use two different sprites to begin with). For the dents, sounds like you just need a few sprites for that and enabled them in a layer in front of your ships when damage occurs