Creep feed profile grinding of Ni-based superalloys with ultrafine-polycrystalline cBN abrasive grits

Abstract

This paper presents the grinding characteristics of a newly developed ultrafine-polycrystalline cBN abrasive grit in creep feed profile grinding of Nickel-based superalloys. Experiments for producing a rectangular-shaped groove on a flat surface in one pass by creep feed grinding have been carried out using the new polycrystalline cBN (PcBN-U) grit and a representative conventional monocrystalline cBN (McBN-B1) grit. The grinding forces in grinding with PcBN-U grits are reduced by 20 ∼ 30% compared with McBN-B1 grits. When grinding with PcBN-U grits, both radial wear and profile wear are less, and hence the grinding ratio is around 4 times higher than that with McBN-B1 grits. The size of grit fracture during the grinding process with PcBN-U grits is smaller than that with McBN-B1 grits. It gives lower wheel wear rate and longer wheel life in grinding with PcBN-U than with McBN-B1.