STUDY OF THE MECHANISM OF EDGE ROUNDING OF HARD-ALLOY MODULAR AND NON-MODULAR WORM CUTTERS DURING GEAR MACHINING

The scientific foundations of research into the processes of rounding the edges of carbide tools during gear cutting are based on the key principles of wear theory, cutting mechanics and tribology. The formation of predicted roundings with a radius of 20–200 μm depends on cutting modes and processing conditions. The reduction of microchips on the edges and the optimization of the geometry of the cutting elements make it possible to increase the strength and wear resistance of the tools. In the initial stage of vibroabrasive processing, macrobrittle destruction of the edges with nonlinear kinetics prevails - the separation of rubble grains comparable to the rounding radius, in the final stage - microbrittle with linear - the separation of single grains comparable to the height of the irregularities. The moment of transition is determined by the amount of rounding, which is critical for macrostrength. The advantage of the exponential model obtained by solving the differential equation for describing the dependence of the rounding radius on the initial radius, the sharpening angle and the duration of processing is shown for various combinations of fillers and machined hard alloys. The kinetics of other microgeometric parameters is described by the same model, but with a finite damping instead of a linear cross section.