Investigating crystallization processes while brazing copper by copper-phosphorus brazing alloy with the purpose of controlling the structure of the brased seam

Abstract

The possibility of predicting the structure of a brazed seam is considered. The brazing temperature is selected as the main method of influence since the composition of the liquid brazing alloy in the seam for eutectic systems will be determined by the line of the liquidus of the phase diagram of the “brazing alloy-brazed material” system. The influence of nonequilibrium crystallization conditions on the structure of the brazed seam is established. It is found that it is insignificant for the Cu-P system due to a small variation in the phosphorus solubility in the solid phase during crystallization. A simple formula for determining the thickness of the brazed seam is suggested. The results of calculations are confirmed by the experiments of brazing copper by the copper-phosphorus brazing alloy. It is shown that it is possible to obtain any eutectic content in the brazing alloy seam and, consequently, vary the strength properties of the seam.