Dissolution and Erosion Phenomena in the Brazing of Aluminum Heat Exchangers

Abstract

On the basis of research, the mechanisms of dissolution and erosion during brazing of aluminium alloys and the influence of these phenomena on brazed joints of heat exchangers are presented. A number of factors have been identified that affect the formation of these phenomena during brazing aluminium alloys, these include : the maximum temperature and holding time at brazing temperature, and the type and amount of filler metal. The research was supported by examples of dissolution and erosion phenomena during series production of aluminium heat exchangers using three brazing profiles (normal, hot and very hot). It has been found that the dissolution of the engine radiator components during brazing, is from 18 to 68%, depending on the brazing profile used. For a very hot profile, erosion in part of the brazed exchanger, even destroys (removes) thin elements of the cooling fins.

Keywords

• filler metal
• heat exchanger
• brazing
• aluminium alloys 3xxx and 4xxx series
• dissolution and erosion phenomena