The grinding speed of superabrasive grinding wheels should be selected based on specific conditions such as wheel type, grinding method, and cooling. Increasing the working speed of the grinding wheel can significantly improve grinding efficiency and grinding ratio (such as increasing the grinding speed of the grinding wheel by 40% and doubling the grinding ratio), and reduce grinding costs. Metal and resin bonded diamond grinding wheels typically have a grinding speed of 15-35 m/s, while ceramic bonded superhard abrasive grinding wheels can increase their grinding speed to 45-160 m/s. The linear velocity of 80-125 m/s has become the mainstream for CBN grinding wheel grinding in the world. The grinding depth is generally 0.002-0.010mm, the workpiece speed is usually 10-30m/min, and the longitudinal feed rate can be taken as 0.3-1.5m/min. Take the maximum value for rough grinding and the minimum value for fine grinding.
The dressing of superhard abrasive grinding wheels is usually divided into two processes: shaping and sharpening. Shaping is the process of micro cutting a grinding wheel to achieve the required geometric shape and accuracy, and breaking the abrasive tip into fine glass fragments to form micro edges; Sharpening is the process of removing the binder between abrasive grains, creating a certain amount of chip space between them, and causing the abrasive grains to protrude beyond the binder, forming a cutting edge.
For porous ceramic bond superhard abrasive grinding wheels (including diamond and CBN grinding wheels), due to the loose nature of the bond, shaping and sharpening can usually be completed in one go; For compact grinding wheels with binders such as resin or metal binders, shaping and sharpening must be performed separately. The most effective shaping tool for superhard abrasive grinding wheels is the diamond type dressing tool. Trimming with single diamond particles often affects the surface accuracy due to tool wear. If diamond rollers are used for dressing, it can avoid rapid wear of the dressing tool and obtain a better grinding wheel morphology. The feed accuracy of the trimming device should be high, and the feed rate should be controlled at the micrometer level each time. Excessive dressing not only affects the quality of grinding, but also greatly reduces the service life of the grinding wheel.
There are many methods for sharpening, generally using mechanical methods (such as cutting in corundum blocks for sharpening, hydraulic jet sharpening, etc.) or electrical machining methods. The latter is mostly used for grinding wheels with metal bonding agents, where the grinding wheel is used as an anode to corrode the metal bonding agent through electrical discharge or electrolysis; If graphite powder is added to the binder, this method is also applicable to resin and ceramic binder grinding wheels.