Posted for "John Barrett" <2thman@olympus.net>:

Metal to metal bonding (aluminum) is a desirable goal and I'm not surprised
to know that it is achievable.  Look at the literature on the subject over
the years.  It wasn't that long ago that it was thought to be impossible or
at least totally exotic.  With improvements in adhesives, it has become
feasible.  But the real breakthrough is in prepping materials and
techniques.  Previously, there was no way short of working in a controlled
atmosphere to remove the oxidation products well enough and even if you
could, the oxide layer would reform too fast to allow a bond.

When bonding aluminum to composite, there is more to consider - the
coefficients of expansion need to be factored in.  Even though the adhesive
may be as strong as you need, if the materials on either side of the bond
are changing dimension at a different rate during temperature cycles, your
bond may lose strength as it experiences thermal cycling.

John Barrett