Profile Grinding of Superalloys with Ultrafine-Crystalline cBN Wheels

Abstract

This paper deals with the grinding characteristics of newly developed polycrystalline cBN (cBN-U) abrasives in creep feed profile grinding of nickel-based superalloys. Experiments for producing a V-shaped groove on a flat surface in one pass by creep feed grinding have been carried out using the new polycrystalline cBN-U and representative conventional cBN (cBN-B) grits. When grinding with cBN-U abrasives, both radial wear and profile wear are less, and hence the grinding ratio is around 10 times higher than that with the conventional cBN-B abrasives. Grinding forces in grinding with cBN-U abrasives are reduced by 20-30% compared with those in Grinding with cBN-B abrasives. The cBN-U abrasive is suitable for the applications with a high dimensional accuracy in creep feed profile grinding for nickelbased superalloys, because it gives less profile wear, and hence better form retention, than conventional cBN abrasive.

Abrasive machining of advanced aerospace alloys and composites

“…In addition, grinding parameters for roughing had to be adjusted accordingly to prevent generation of excessive cutting temperatures for newly dressed wheels and to suppress chatter when operating with worn wheels. Ichida et al [103] evaluated the grinding behaviour of Nimonic 80A when using vitrified bonded ultrafine-crystalline CBN (CBN-U) and conventional monocrystalline CBN (CBN-B) wheels. The former exhibited a 10-fold increase in wheel G-ratio together with correspondingly lower grinding force components (F n and F t ) and specific energy (e c ) compared to the CBN-B product.…”

The Ultra-hard Honing Oilstones

“…Ichida et al [14][15][16] deals with the grinding characteristics of newly developed ultrafine-polycrystalline CBN (CBN-U). The results show that the grinding ratio is around 10 times higher than that with the conventional CBN (CBN-B) abrasives.…”

Development of a High Performance Vitrified Grinding Wheel using Ultrafine-Crystalline cBN Abrasive Grains

“…Such high grinding ratio is another of the important features of grinding with cBN-U grains. Therefore, cBN-U may be widely used for grinding various difficult-to-grind materials such as superalloys, high-speed steel, and so on (14) .…”