condensor: profile, section: animating and modelling

I work on a project showing a technical unit with waterboiler and condensator. The animation shall allow a view inside the system to visualize the internal activities. The difficulty for me is here the fading out of the parts of the machine’s surface to look inside.So my first idea was to cut the objects using i.e. the knife tool and then “separate” to single objects.
Then I could assign copies of the original materials to the new objects or without separating I could use multimaterials. But this way I will habe dozens of identical materials that just differ from their original by the animated alpha value. Do you have experience which alternate approach I could take?

Concerning the modelling: After cutting the alpha-animated parts I think I will extrude the edges to get a look of wall thickness. (I was looking for the “solidify mesh” script but I couldn’t find it know where. Can you point me to a url?)

Concerning the animation: I thought if I could take advantage of the nodes system. Do you think I could overwrite the alpha-values of the basis-material using a second material(node). So all other material properties would be taken from the unchanged original material.

I would be happy if you could help me out, show me some tips or pointing me to a tutorial covering this issue.

Thank you