"Mark Andrew Spence" wrote

The TICONDROGA and SPRUANCE class ships had aluminum superstructures which
were welded to a "fusion bar" which consisted of a piece of very clean and
smoothly-machined piece of aluminum FLAT BAR joined to a very clean piece
and smoothly machined piece of steel flat bar via explosive charges.

What was the purpose of the explosive charges? (besides, to go "bang" g)
--
Jim in NC