We all know that diamond grinding wheels can process very hard materials, and therefore they are often used without hesitation. However, some customers have found cracks appearing in their grinding wheels during use. What causes this?
Reasons for cracks in diamond grinding wheels:
1. Surface cutting cracks are mainly caused by excessively high instantaneous temperatures in the cutting contact zone during the cutting process, resulting in shallow compressive stress distribution on the cutting surface and excessively high tensile stress values near the surface exceeding the tensile strength of the material. Therefore, during the cutting process, the generation of instantaneous high temperatures should be minimized and prevented, thus reducing and preventing the generation of residual tensile stress.
2. Not only should cutting cracks be avoided, but also cutting burns. During diamond processing, the instantaneous temperature of the tool surface depends on the processing method, the characteristics of the diamond tool, and the cutting parameters.
3. The greater the angular velocity and axial cutting speed of the diamond grinding wheel, the higher the wheel hardness, the finer the grit size, the lower the thermal conductivity of the tool material, and the greater the wheel wear, the higher the cutting temperature will rise, making it more prone to cutting cracks and grinding burns.
Solutions for cracks in diamond grinding wheels:
1. When dressing the grinding wheel using its side, the operation must be performed according to regulations. Do not use the side of the grinding wheel for dressing operations. Check if the grinding wheel assembly is incorrect.
2. Inspect and repair the machine tool spindle to improve its precision.
3. When replacing the grinding wheel, be sure to select a diamond grinding wheel with the same size as the shaft and use grinding wheels of the same specifications.
4. Strictly follow the instructions or the diamond grinding wheel user manual for accurate cutting operations.
Diamond grinding wheels are also called superhard grinding wheels. As the saying goes, things that are too hard are too brittle, especially ceramic diamond grinding wheels, where the binder is ceramic (glass), which is very easy to break. If the metal base material breaks, it is usually due to impact during use. If the fused coating breaks due to reasons other than impact, it is mostly due to poor temperature control during manufacturing, resulting in uneven fusion. If the fused coating is not properly bonded to the base material or the coating peels off, it is due to uneven application of adhesive during manufacturing or insufficient interlocking of the serrated teeth of the base material. Minor coating fractures can be repaired at the factory; extensive damage requires replacement.