WC particulate reinforced joint by ultrasonic-associated brazing of WC-Co/35CrMo

摘要

During the hybrid ultrasonic frequency induction brazing of tungsten carbide-cobalt/35CrMo (WC-Co/35CrMo) steel, a Ag-Cu-Zn-Mn-Ni metal was utilized as a filler metal, the vibration frequency was 21 kHz, and the brazing temperature was varied from 710 degrees C to 820 degrees C. WC particles dispersed in the bond with the ultrasonic vibration, which phenomenon did not occur during traditional brazing processes. Based on the evolution of the microstructure of the WC particles in bonds formed at different ultrasonic times, the dissolution behavior of cobalt (Co) in Ag-based filler metal was investigated. A migration model of WC particles into the bonds was proposed that enables the control of the extent of reinforcing WC particles. Compared with conventional frequency induction brazing, WC particles in the bond via this ultrasonic-assisted brazing technique strengthened the joints significantly, resulting in a shear strength increase of 17% (approximately 408 MPa). (C) 2016 Elsevier B.V. All rights reserved.