Significance of the brazing gap in the brazing of aluminium heat exchangers for automotive industry

Abstract

The paper presents the influence of the brazing gap width on the structure of bonded joints during the production of aluminum heat exchangers, using brazing technology, in tunnel furnaces with controlled atmosphere. Based on the wedge test, an analysis and qualitative assessment of brazed joints was made for the changing width of the brazing gap and the filler metal used. For the received brazed joints, metallographic tests were carried out using light and electron microscopy (SEM) and microhardness measurements in the characteristic areas of brazed joints. Based on the results obtained, the recommended width of the brazing gap was determined.

Keywords

• brazing gap
• brazed joint microstructure
• brazing wedge test
• aluminium brazing
• aluminum heat exchangers