Corrosion Resistance of Brazing Filler Metals and Brazed Copper Joints

Abstract

In this study, I investigated about corrosion loss of various filler metals with Ag-P-Cu, Ag-Cu-Cd-Zn and Cu-Zn systems and about the change of tensile strength of brazed copper joints with various filler metals in various corrosive solutions at room temperature.
The results of investigation are concluded as follows;
1) When immersed in 10%H₂SO₄ solution, Ag-P-Cu systems are better than Ag-Cu-Cd-Zn and Cu-Zn systems on corrosion loss and the decrease of tensile strength of brazed copper joints.
2) When immersed in 10%HCl solution, the corrosion loss of these filler metals are less than pure copper, and its of Ag-Cu-Cd-Zn and Ag-P-Cu systems.
3) In 10%NH₄OH solution, Ag-P-Cu systems are very corrosive in comparison with Ag-Cu-Cd-Zn and Cu-Zn systems.
4) In 5%NaCl solution, the corrosion resistance of Ag-Cu-Cd-Zn systems are better than the other systems.
5) When immersed in saturated H₂S solution, the filler metals contained phosphor are corrosive than the other filler metals.