Study on Microstructure and Properties of Brazed Joints Using YG6X Cemented Carbide and 65Mn Steel

To meet the comprehensive requirements for high wear resistance and toughness in circular saw blades with serrated teeth, this study employed BAg5CuZnNiMnIn alloy as the brazing filler material. Through high-frequency induction brazing technology, a reliable connection was achieved between YG6X cemented carbide (saw blade tooth tip) and 65Mn steel (saw blade body). Microstructure and element distribution of the brazed joint were characterized using optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Shear strength tests investigated the effects of weld width and induction tempering temperature on the mechanical properties of the joint. Results indicate: The brazed joint formed a stable metallurgical bond with no visible cracks, though partial porosity existed within the weld. It exhibited a “65Mn steel-weld-YG6X cemented carbide” structural characteristic; Fe, Cu, Co, and other elements exhibited mutual diffusion at the interface; weld width significantly influenced joint strength, with shear strength increasing by approximately 27.2% when width decreased from 20 μm to 8 μm; Induction tempering temperature regulated weld shear strength, with optimal strength (161.3 MPa) achieved at 400°C tempering—a 20 MPa increase over untempered specimens. Beyond 500°C tempering, shear strength progressively declined below untempered levels.