Analysis on the influence factors of brazing strength of PDC based on different base metal

With the continuous expanding of the application of PDC bit in complicated formation, the requirements for welding strength of PDC and substrate materials is increasingly high. In order to explore the brazing process of PDC compacts and different substrate materials, the PDC compact were brazed in the atmosphere with two substrate materials (the samples of matrix and carbon steel PDC bit, for short, the matrix specimen and the carbon steel specimen) and two brazing filler alloys, using flame brazing and high-frequency induction brazing. The influence of the brazing temperature, brazing materials and brazing mode on the welding performance of PDC compacts and different base materials was studied, the changing curve of the shear strength with temperature was obtained. At the same time, the brazing surface was observed using an optical microscope. The results show that when the PDC compact and the matrix specimen are brazed, it is brazing between the cemented carbide, the brazing solder can dip into base metal effectively and the strength of welded joint is high. When the PDC compact and the carbon steel specimen are brazed, it is brazing between the cemented carbide and the dissimilar. In order to improve the shear strength, the brazing temperature may increase appropriately or of brazing filler metal with high Ni content may be used.