What are the differences between SDC grinding wheels and CBN grinding wheels?

1. Different Applications:

SDC grinding wheels are mainly used for machining hard and brittle materials, such as cemented carbide, ceramics, glass and other workpieces.

CBN grinding wheels are mainly used for hard and tough materials, especially ferrous metals, including various steel parts and cast iron. Typical workpieces include automotive components (crankshafts, camshafts), hydraulic parts and compressor components.

2. Different Costs:

In terms of production cost, CBN grinding wheels are far more expensive than SDC diamond wheels. If a workpiece can be processed by either wheel, SDC diamond wheels are preferred over CBN wheels.

3. Different Heat Resistance:

CBN (Cubic Boron Nitride) can withstand temperatures of 1250–1350°C, higher than the 800°C temperature resistance limit of SDC diamond wheels. It prevents chip adhesion during grinding and cutting of ferrous materials, making it the ideal wheel for grinding temperature-sensitive metals such as hardened steel, high-vanadium high-speed steel and aluminum high-speed steel.

Nevertheless, CBN grinding wheels cannot replace SDC diamond wheels for grinding cemented carbide and non-metallic hard materials. Only oil-based coolant can be adopted for CBN grinding rather than water-based coolant. Under high grinding temperature, CBN will chemically react with alkaline aqueous solutions. CBN decomposes in alkaline solution at 300°C and slightly decomposes in boiling water, which destroys the crystal structure of abrasive grains.