Abstract: In order to study the effect of different brazing cooling rate on the brazing residual stress and equivalent elastic thermal strain of plate-fin structure, a three-dimensional thermal stress analysis model of plate-fin structure is established, and the variation of brazing residual stress and equivalent elastic thermal strain under different brazing cooling rates are simulated and analyzed using the thermal-structural coupling method. The results show that the brazing residual stress of fin-structure is decreased with the decrease of the brazing cooling rate. The difference between the brazing residual stresses of the plate-fin structure is also different for different brazing cooling rates, and when the brazing cooling rate is less than a certain value, the brazing residual stress of the plate-fin structure will be approximately constant. The smaller the brazing cooling rate, the smaller the risk of fracture in the weak parts of the plate-fin structure. The brazing cooling rate has little effect on the equivalent elastic thermal strain of the plate-fin structure.

Key words: brazing cooling rate, plate-fin structure, brazing residual stress, equivalent elastic thermal strain