A three-layer aluminum clad sheet composed of 4343 (filler alloy, thickness
: 10 mum)/3003 (core alloy, thickness: 80 mum)/4343 (filler alloy, thicknes
s: 10 mum), which is being used as brazing sheet materials for automotive c
ondensers, was fabricated by casting --> hot rolling --> cold rolling --> i
ntermediate annealing (IA) --> final cold rolling (CR) and the relationship
between the IA/CR condition, microstructure and brazing characteristics wa
s investigated. When IA/CR was performed under the condition of 600-690 K/1
0%, the core contained non-recrystallized structure, and the melting filler
penetrated into the core along the subgrain boundaries during the brazing
process, resulting in decreased brazeability with accompanying increase in
eroded area. When IA/CR was carried out under the condition of 600 K/over 3
0% or 690 K/over 45%, finely recrystallized grains were formed in the core
during the brazing process, which promotes filler penetration along the gra
in boundaries. In this case, the brazeability deteriorated with the increme
nt in eroded area. If IA/CR was done under the condition of 690 K/20-45%, t
he specimens exhibited excellent brazeability with suppressed erosion owing
to the formation of coarsely recrystallized grains. (C) 2001 Elsevier Scie
nce B.V All rights reserved.