Resin Bond Diamond and CBN Grinding wheel dressing and sharpening

Diamond and CBN abrasive grains

Modern grinding technology uses grinding particles and dressing particles made of diamond (DIA) or cubic boron nitride (CBN). Diamond exists in natural or synthetic forms, while CBN is a purely synthetic product. What they have in common is the cubic crystal structure and the resulting physical properties of the DIA and CBN particles (Table 1). Diamond is significantly harder than CBN (Figure 1), but CBN has a lower oxidation tendency and higher chemical stability, so thermal

The stability is clearly outstanding (Figure 2).

Based on your specific job requirements, our professionals will advise you on the ideal coordinated configuration of grit size and abrasive grain quality, which are the main factors influencing grinding performance. The general interrelationship between tool quality, grinding characteristics and abrasive grain quality can only be expressed in the context of the application. The cutting structure on DIA and CBN abrasive grains is the basis for grinding suitability.

Generally speaking:

Friable abrasive grain types can improve the cutting ability of the grinding wheel, but reduce the achievable surface quality. Blocky abrasive grains increase the service life of the grinding wheel and the surface quality achieved, but reduce cutting ability. Abrasive grains are often coated with copper or nickel to improve their fixation in the binder, heat dissipation, and chemical and mechanical properties. Coated abrasive grain qualities are generally used in synthetic resinbonded tools.

Grinding wheel dressing and sharpening

Dressing of the grinding wheel - Dressing is to dress the grinding wheel into precise geometric dimensions and shapes, which is a key factor in achieving grinding results. Any axial or radial deformation will cause vibration, and the corresponding result is poor edge quality and poor surface finish. If the requirements are not met, the life of the grinding wheel will be abnormally shortened.

Choosing the appropriate dressing wheel is very critical to the dressing results, including abrasive type, particle size, hardness, etc. The following is the dressing wheel recommendation for 3M grinding wheels:

. It is very important to choose the corresponding dressing wheel type, particle size, hardness and parameters.

·It is recommended to install it on the grinding wheel spindle for overall dressing

·It is recommended to trim in the same direction

. Use coolant whenever possible

. When dressing fine-grained grinding wheels, the rotation speed and feed rate should be reduced accordingly. Before dressing, you can mark the periphery of the grinding wheel so that you can easily see whether the entire grinding wheel has been trimmed.

Trimming precautions

. Linear speed of grinding wheel to be dressed: 2-6m/s

. Dressing wheel linear speed: 8-20m/s

. Rough trimming: 0,02-0,08 mm/time

·Finishing: 0,005-0,02 mm/time

. Swing speed: 200-1000mm/min

. Increasing the grinding wheel rotation speed or reducing the feed speed can increase the surface finish

The dressed grinding wheel has almost no free abrasive grains and needs to be sharpened to obtain exposed abrasive grains.

. Soak the whetstone in clean water or clean grinding oil for about 5 minutes before use.

. The rotation direction of the diamond grinding wheel during dressing should be consistent with that during grinding.