Carbide tool machining method

Carbide blade, high hardness and brittleness big, poor thermal conductivity, thermal shrinkage, often should use diamond grinding wheel for grinding. But because of the diamond grinding wheel is expensive, the wear is not easy to repair, after so many factories are still using common grinding wheel for grinding. In the process of grinding, because of the hard alloy hardness is higher, ordinary grinding wheel grinding grain of passivation extremely easily, severe friction blade surface produce local high temperature, form the attached heat stress, easy to cause the thermal deformation and thermal crack, directly affects the service life of the cutting tool and machining quality. Therefore, we should take the necessary measures to prevent the production of grinding crack. Through the processing practice, summarizes the following which can effectively prevent or reduce the technological method of grinding crack. 1 negative blade sharpening method negative blade sharpening method is to point to in front of the grinding tool, first on the knife before or after knife grinding out a negative side to take. Tungsten carbide belongs to hard brittle materials, grinding with the grinding wheel vibration cutting tool under impact load, vibration prone to crack; At the same time, the grinding of sudden warming and cooling thermal stress may exceed the carbide ultimate strength and thermal crack generation. Using negative blade sharpening method can improve the blade strength, enhance the blade vibration resistance and the ability to bear impact load, and increase the heating area, to prevent the grinding heat a large number of guide blade, so as to reduce or prevent crack. 2 with molybdenum disulfide infiltrating wheel under the normal temperature condition, the powdered molybdenum disulfide and anhydrous ethanol made from the mixed solution, and then in an airtight container (prevent ethanol volatilization) will immerse new grinding wheels in mixed solution, take out after 14 hours, natural drying 18 ~ 20 hours, the grinding wheel is completely dry. By the wheel of the internal space is full of molybdenum disulfide, the abrasive can lubricate the effect, make the wheel clearance good, not easy jam. Trials show that, with molybdenum disulfide infiltration over grinding wheel grinding carbide blade, sharp grinding, grinding grain not easy passivation, workpiece deformation is small, smooth chip removal, basic strip of wear debris shapes, with most grinding heat, so as to improve the grinding effect, improve the coefficient of the blade. If reasonable selection of grinding dosage too much friction in the process of grinding, grinding temperature can lead to a sharp rise, the blade is easy to burst, so rational selection of grinding dosage is very important. Commonly used reasonable grinding dosage is: the circular velocity v = 10 ~ 15 m/min, vertical feeding f = 0.5 ~ 1.0 m/min, f = 0.01 ~ 0.02 mm/trip. Manual grinding, both longitudinal and transverse feed shoulds not be too big. 4 other technological measures tool holder and tool clamping rigidity instability, spindle runout can lead to the production of grinding crack, therefore, made up of machine tool, grinding wheel, fixtures and cutting tools machining system should have sufficient rigidity, and should be controlled grinding wheel axial and radial runout. Grinding cracks caused by carbide cutting tools of many factors, only choose the appropriate grinding wheel, adopting reasonable grinding process at the same time, to be effective to avoid crack, improve the quality of grinding.