Influence of CBN Abrasive Properties on the Grinding Performance of Resin Wheels

With the continuous advancement of high-efficiency grinding technology, the market has higher and higher requirements for the performance of resin-bonded CBN grinding wheels, and the requirements for the types of processing materials are also increasing, which requires resin-bonded CBN grinding wheels to have common suitability.

When grinding gray cast iron with CBN abrasive resin grinding wheel, CBN abrasive with suitable strength is recommended, because the structure of gray cast iron can be regarded as the matrix of carbon steel and flake graphite. The mechanical properties of gray cast iron are related to the structure of the matrix and the shape of the graphite. The flake graphite in the gray cast iron severely splits the matrix, and it is easy to cause stress concentration at the sharp corners of the graphite, which makes the tensile strength, plasticity and toughness of the gray cast iron far away. Lower than steel, therefore, grinding low-strength cast iron materials does not require very high-strength CBN abrasives. In addition, the combination of CBN abrasive and resin bond cannot produce chemical bonding, and the bonding force is mainly increased by mechanical fitting. Therefore, CBN abrasive resin grinding wheel with rough surface morphology and moderate strength is selected to process gray cast iron.

High-speed steel is a kind of tool steel with high hardness, high wear resistance and high heat resistance. , improving the service life. Therefore, the hardness value of high-speed steel is generally around HRC62-65. When processing high-speed steel, because of its many hard particles, CBN abrasives with better strength and better thermal stability are selected and resin-bonded to form grinding wheels for high-speed processing. steel.

When CBN abrasive resin bond grinds stainless steel, the chips of stainless steel have a certain adhesion to the grinding wheel, which is easy to block the pores and burn the workpiece. If the self-sharpening of the abrasive is not good, it is easy to fall off before passivation, resulting in the grinding of the workpiece and the ablation of the workpiece, which eventually leads to a decrease in the grinding efficiency. When processing viscous stainless steel materials, it is necessary to select CBN abrasive with slightly less thermal shock resistance and more brittle.

When resin-bonded grinding wheels made of different CBN abrasives are used to process nitrided stainless steel materials, nitrided stainless steel is a hard and tough material, and the nitrided products have excellent wear resistance, fatigue resistance, corrosion resistance and high temperature resistance. . The hardness value of the workpiece surface after nitriding is high, and the CBN abrasive with a higher blade will be quickly ground away to prevent the blade from being pulled out. This requires the resin bond to have a very high grip on the CBN abrasive. The choice of abrasive needs further research to solve the difficult grinding problem of nitrided stainless steel.

In the case that the resin bond has a weak holding force on the abrasive, the performance index of the CBN abrasive does not determine the performance of the formed grinding wheel. Therefore, the quality of CBN abrasives cannot be judged simply based on the strength data, but the CBN abrasives should be selected according to the characteristics and morphology of the abrasives, as well as the requirements of the processing materials and processing conditions.

In the case of processing gray cast iron, high-speed steel, stainless steel, and nitrided stainless steel, it is recommended to select CBN abrasives with rough morphology and moderate static pressure crushing load.