Title of Paper:Micro-fracture mechanism of polycrystalline CBN grain during single grain scratching tests based on fractal dimension analysis

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Affiliation of Author(s):机电学院

Journal:Precis Eng

Abstract:The wear phenomenon is an important issue that affects the grinding performance of polycrystalline cubic boron nitride (PCBN) grinding wheel. To explore the wear mechanism, single grain scratching tests were conducted on the nickel-based superalloy Inconel 718. Fractal theory was applied to evaluate the grain wear process, and the influences of undeformed chip thickness agmax and grinding wheel speed vs on grain wear were analysed. The variation in fractal dimension, grinding force and grinding force ratio were discussed. Results show that the micro-fracture is caused by the crack, and the adhered grinding chip leads to the attrition wear of PCBN grain. The average specific material removal volume of monocrystalline CBN grain is approximately 10.7% that of PCBN grain when macro-fracture occurs. The effect of agmax on grain macro-fracture is stronger than that of vs. Furthermore, the grinding parameters should be set as follows: vs of 80 m/s and agmax in the range of 0.1–0.67 μm. These settings help improve the grain micro-fracture phenomenon in high-speed grinding. © 2019 Elsevier Inc.

ISSN No.:0141-6359

Translation or Not:no

Date of Publication:2019-09-01

Co-author:Zhu, Yejun,Rao, Zhiwen,Yang, Changyong

Correspondence Author:dwf