A microstructure-based mathematical model for predicting vacuum brazing strength

Abstract

Brazing strength is a very important mechanical property for brazed joints, but studying brazing strength solely through experimental methods is time-consuming, laborious, and costly. Therefore, it is of great significance to establish a mathematical model for predicting brazing strength. We have presented a new mathematical model for precisely predicting vacuum brazing strength based on a small amount of experimental data. This model applies diffusion theory and derives a functional relationship between brazing strength and brazing process parameters based on some assumptions and approximations, and the undetermined coefficients in the functional relationship can be fitted using Origin software. The vacuum brazing experiments on Cu/Ag-49Cu-7Ga/Cu were conducted to validate the model, the error between experimental and calculated values is within 10 %, and the trend of experimental data is consistent with that of the calculated results. The brazing strength first increases and then decreases with the increase of brazing temperature or the extension of brazing time. This microstructure-based mathematical model can be used to predict the maximum brazing strength with high accuracy and to determine the optimal brazing process, reducing experimental costs and providing guidance for scientific research and industrial production.