Experimental Research On The Enhanced Cutting Edges Of Hss Taps With The Method Of Electrolysis

The cutting edge of the cutter teeth on high-speed steel taps becomes slightly saw-toothed or flaked after being ground with wheel. These deficiencies are the sources of stress concentration and expand easily during the cutting process. The wear and tear of the cutter teeth is thus accelerated and the life of high-speed steel taps is shortened. In order to extend the life of the taps, the principle of electrolytic polishing is applied in this thesis to remedy the micro-deficiencies on the surface of the cutting edge and, for the enhancement, to passivate the cutting edge and the edge area into an arc-shaped edge with a certain radius. Therefore, it is of theoretical and practical significance to study the technology of electrolytic enhancement of the cutting edge and the edge area of the cutter teeth on high-speed steel taps.After a thorough understanding of the principle of electrolytic polishing, an electrolytic device is developed, which fulfils the functions to agitate electrolyte at the anode, the rotation rate of which can be regulated, to adjust the distance between the anode and the cathode, to regulate the voltage and the current, and so forth. Through this device, the regularities of the influence of current density, electrode distance, the temperature of the electrolyte, and reaction time, etc. on the enhancement are studied.Using the finite element software DEFORM 2D, the unified model and the equivalent finite element model of the cutting edge and the edge area are established to simulate the cutting force and the tool wear. The optimum form of the cutting edge and the edge area is ascertained and, through the experiment of electrolytic enhancement, the cutting edge and the edge area are enhanced to the optimum form.Finally, the enhanced taps and the taps which are not enhanced are respectively tested by tapping to verify the enhancement of the taps, and then the enhanced taps and the modified tooth taps are respectively tested by tapping to verify the wear resistance of the enhanced taps.The result of the experiment indicates that the micro-deficiencies on the cutting edge of the taps after an electrolytic enhancement are evidently reduced, an arc-shaped edge with a certain radius is formed, and the value of the surface roughness of cutter teeth on the taps is reduced; thus, the wear resistance and the life of the taps are extended.