Abstract: Based on the experimental results of grinding groove bottom using electroplated CBN cup quill, a new type cup CBN quill is developed in order to reduce corner radius between groove bottom and flank. According to experimental study on its grinding performance, improving measures are presented, and a good grinding result is obtained. As a result, the corner radius of new type cup CBN quill is less than 0.2 mm and remarkably less than one of electroplated cup CBN quill, the reduced factor is over 60%. It is discovered that flank wear on the effect CBN grain and subsequently the break of the CBN grain in the grinding process make reducing the protrusion height of effect grains, and all of the CBN grains on wheel surface become effect grains successively. Therefore, improving the wearability of CBN grain and heightening the toughness of CBN grain to reduce the break are effect measures to increase life of new type CBN quill. High-toughness polycrystalline CBN grains (GE 550 type) are chosen, it makes the life of new type CBN quill be increased by a factor of 6.75.

Key words: Corner radius, Bond, CBN quill, Face grinding, Grinding force