Interfacial behavior of brazed Cu-Zn filler subjected to electromagnetic coupled cryogenic treatment

Abstract

• A new electromagnetic coupled cryogenic treatment was applied to Cu-Zn interface. • The shear strength of the treated Cu-Zn filler interface increased by 35.2 %. • The treatment relieved the residual tensile stress of the Cu-Zn interface. • The dendrites and finer α-Cu(s.s), and soft β-Cu(s.s) increased shear strength. A Cu-Zn filler was used for the induction brazing of WC-11Co cemented carbide and AISI 4140 alloy steel. To enhance the shear performance of the brazed interface, a new electromagnetic coupled cryogenic treatment was proposed. Results show that the shear strength of the treated interface increased by 35.2%, and that the fracture surface exhibited more ductile fracture characteristics. The distinct microstructure after treatment was from precipitation of the soft β-Cu(s.s), and the grain refinement and dendritic structure were from α-Cu(s.s). The relaxation of residual tensile stress on the WC-11Co side also enhanced the shear strength.