Brazeability of cold rolled three layer Al-7.5Si/Al-1.2Mn-2Zn-(0.04~1.0)Si/Al-7.5Si(wt.%)clad sheets

초록

The effect of silicon content in the core alloy on the brazeability of three layer aluminum clad sheets was investigated using the clad sheets composed of Al-7.5wt%Si alloy(filler, thickness:10micrometer)/Al-1.2wt%Mn-2wt%Zn based alloy containing 0.04~1.05wt% Si(core, 80micrometer) /Al-7.5wt%Si alloy(filler, 10micrometer). It was revealed that the clad sheets with 0.04~0.64wt% Si core have an excellent sagging resistance(brazeability) with a limited erosion owing to the formation of a coarsely recrystallized grain structre in the core during brazing. In contrast, if the Si content in the core increased to about 1%, the sagging resistance of the clad sheets decreased with severe erosion due to an incomplete recrystallization of the core during brazing.