Laser Welding of Heterogeneous Materials Ni-Fe-Cu and Fe-C-Mn-Si for Production of Drilling Tools

A technology has been developed for laser welding of dissimilar materials based on the Ni-Fe-Cr and Fe-C-Mn-Si systems, which can replace the technology of brazing joints between a diamond unit and a steel tube in crown drill bit manufacturing. The optimal parameters for obtaining welded seams without internal defects using laser radiation were determined. The amount of heat input as well as the energy per unit volume of the molten material were also calculated. It was found that the use of optimal energy modes of laser treatment made it possible to avoid the destruction of diamonds during the welding process. Welding led to the formation of martensitic structures in and around the weld. Despite this, preliminary tests of the crown drill bit showed the advantage of a laser-welded joint over a brazed one.