FABRICATION AND BRAZEABILITY OF ALUMINUM 3003 BASE CLAD SHEET BY ROLLING

초록

A three layer aluminum clad sheet omposed of 4343/3003/4343, which is being used as brazing sheet materials for automotive condensers, was fabricated by casting-hot rolling-cold rolling-intermediate annealing-final cold rolling, and the relationship between IA.CR condition, microstructure and brazing characteristics was investigated. When IA/CR was performed in the condition of 330~420oC/10%, the core contained non-recrystallized structure. and the melting riller penetrated into the core along the subgrain boundaries during brazing process, resulting in decreased brazeability with accompanying increase in eroded area. When IA/CR was carried out in the condition of 330oC/over 30%, finely recrystallized grains were formed in the core during brazing process, which promotes filler penetration along the grain boundaries. In this case, brazeability was deteriorated with the increment in eroded area. if IA/CR was done in the condition of 420oC/20~45% or 330oC/20~30, the specimens exhibited excellent brazeability with suppresesed erosion owing to the formaion of coarsely recrystallized grains