Dressing Mechanism and Evaluations of Grinding Performance with Porous cBN Grinding Wheels

Cubic boron nitride (cBN) grinding wheels play a pivotal role in precision machining, serving as indispensable tools for achieving exceptional surface quality. Ensuring the sharpness of cBN grains and optimizing the grinding wheel's chip storage capacity are critical factors. This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method. It investigates the impact of blasting parameters—specifically silicon carbide (SiC) abrasive size, blasting distance, and blasting time—on the erosive wear characteristics of both the metal bond and abrasive. The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond. Following a comprehensive analysis of the material removal rate of the metal bond and the erosive wear condition of cBN grains, optimal parameters for the working layer are determined: a blasting distance of 60 mm, a blasting time of 15 s, and SiC particle size of 100#. Furthermore, an advanced simulation model investigates the dressing process of abrasive blasting, revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains, thereby enhancing fracture toughness and impact resistance. Additionally, a comparative analysis is conducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels. The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force, temperature, and chip adhesion, thereby enhancing the surface quality of the workpiece.