Development of Ultrafine-Crystalline cBN Abrasive Grains for Innovative Grinding Technology

This paper presents some mechanical properties and grinding characteristics of newly developed ultrafine-crystalline cBN (UcBN) abrasive grains. This new UcBN grain possesses an ultrafine crystal structure composed of sub-micron sized primary crystal grains. The fracture strength of the UcBN grain is about 1.5 times higher than that of conventional polycrystalline cBN grain. The grinding ratio in grinding with the UcBN grain is 4–10 times higher than those in grinding with conventional typical monocrystalline and polycrystalline cBN grains. Therefore, the UcBN abrasive grain has an enough ability to innovate the grinding technology.