Microstructure and properties of rapidly solidified Ag-Cu-Sn ternary brazing fillers

The phase constitution,morphology,electrical resistivity and mechanical properties of Ag_42.47Cu_57.53-xSn_x(x=12.23,12.94,13.65,mass fraction %) prepared by melt-spun method are investigated.The results indicate that the microstructure of the alloys consists of(Ag),α-Cu and a few of Cu_13.7Sn phases;with the rise of tin content,the electrical resistivity increases for refining of the microstructure and increasing of grain boundary amount and solute-trapping;on the other hand,fine crystal strengthening and solution hardening will result in the increment of tensile strength from 280 to 360 MPa,but the elongation reduces from 5 % to 2.8%.The ranges of solidus and liquidus temperature of those alloys are 590 to 616 ℃ and 615 to 622 ℃ respectively,and the temperature range increases with the increasing of tin content.