Weldability and Microstructure of Copper Joints Welded by Two Kinds of Phosphor-copper Brazing Filler Metal

The chemical composition,melting performance and wettability of two phosphor-copper brazing filler metals of BCu80PAg and L-Ag15P were studied,and the mechanical properties and microstructure of copper joints welded by these two filler metals were compared.The results show that the chemical composition homogeneity and wettaility of L-Ag15P was better than that of BCu80PAg,and the melting interval of the former was more narrow than that of the latter.Mechanical property of the joints welded by these two filler metal was comparative.Microstructure of the brazing seam with these two filler metals both was hypoeutectic.The primary phase was α-Cu solid solution rich in Ag and P and the eutectic was α-Cu solid solution and Cu3P compound.