For what its worth, there was an episode of Mythbusters where they showed the effects of sword to sword blows (they were testing the myth of cutting 1 sword in half with another in combat- a frequent occurrence in movies).
After determining the speed of a typical strike by testing real swings by practiced martial artists (upwards of 45mph- other sources have recorded tip speeds up to 75mph), they did some impact tests.
The only swords that broke were modern replicas. There was some nicking, and the slo-mo camera even showed some swords flexing out of the way, avoiding the full force of the blow by bending like a blade of grass.
Even a collisions between the most massive swords they tested only resulted in nicks and/or dulling. Most of the damage was easily worked out with a good sharpening.
And there was an episode of a show dealing with the weapons of England on one of the various educational/history channels that showed the effects of a sword-blow on a ballistic-gel dummy through various Western armors. The results showed what was suggested earlier- that a solid blow from a sword against Western plated armor was essentially a blunt, crushing blow that did most of its damage through hydrostatic shock.
They even showed the "Murder Blow"- in which the sword is gripped on the blade (with gauntleted hands, of course) and the sword's heavy crossbar is used as the striking point- essentially turning the sword into a blunt pick.
While a helm turned most of the blow, the hydrostatic shock at that small point was still sufficient to concuss a human being, possibly to the point of unconsciousness, which would leave the opponent vulnerable to a coup-de-grace.
Examine what happens with a good meat cleaver. One of those will chop through deep muscle tissue and bones all day with minimal damage, after all.
For more info, you might check out ARMA (
http://www.thearma.org/) or Swordforum (
http://swordforum.com/)- lots of well informed people at those locations- or jot a note to one of the world's finer armories. I've written to people at several and they've been most helpful.