Wear study of single PCBN abrasive in high speed grinding Inconel718

CHENG Qiang, LIANG Guo-xing, HAO Jian-yu, ZHANG Yu
(School of mechanical and vehicle engineering, Taiyuan University, Taiyuan 030024, China)

Abstract: Aiming at studying the wear mechanism of a single PCBN abrasive grain at high-speed grinding of Inconel718, the grinding force, the material pileup ratio and the wear of the abrasive grains during the high-speed grinding experiment were studied. The MV-40 CNC machining center was employed in the process of High-speed grinding Inconel718 with single abrasive grain. The grinding force was measured by a dynamometer, the grinding crack and abrasive wear were observed with a 3D profilometer and super depth-of field microscope, and the material pile-up ratio and abrasive grain wear change law were analyzed. The wear of abrasive grain was analyzed from the angle of grinding force ratio, cross section of grinding cracks and pile-up ratio. The results indicate that during the initial wear stage, the tip of the abrasive grain appeared macro-fracture, material adhesion and crack, and during the stable wear stage, the crack expanded along the cutting edge until new cutting edges were formed. The grinding force ratio (Fn/Ft) and pile-up ratio will be increased by the passivation of the abrasive grain at the initial wear stage, while the grinding force ratio (Fn/Ft) and pile-up ratio will be decreased by the formation of new cutting edges at the stable wear stage. The increase of grinding depth will aggravate the wear of abrasive grain, and the grinding force ratio (Fn/Ft) will appear earlier than the inflection point.
Key words: Inconel718; grinding force; pile-up ratio; abrasive wear