I may be wrong, but...

I seem to recall a study done in the mid/late 80s that showed, I think, improved strength from joints or material around joints (the heat affected zone, or HAZ) heated at the higher temperatures required for welding, but for less time, compared to the longer time spent at lower tempertures to ensure brazing material filled all the joints or built up a good fillet. I think Keith Bontrager was involved with, or conducted, this study.