On the grinding performance of metal-bonded aggregated cBN grinding wheels based on open-pore structures

Abstract

Metal-bonded aggregated cubic boron nitride (cBN) grinding wheels were developed by employing open-pore structures in abrasive layers, aiming to solve the problems, such as severe tool wear, low machining efficiency, and poor quality stability with conventional abrasive grinding wheels. Comparative grinding performances, including grinding forces and force ratio, grinding temperature, specific grinding energy, ground surface roughness were performed between vitrified monocrystalline cBN wheels and porous aggregated cBN wheels. Characterisation of morphologies, such as pore structures and tool wear features were also conducted. Results show that the as-sintered porous aggregated cBN wheels possess the lower grinding forces (reduced by 35.9%–43.3% for Fn′; 3.9%–18.8% for Ft′), a smaller grinding temperature (decreased by 10.4%–71.8%), and a stable grinding force ratio of 2.5 in comparison of vitrified monocrystalline cBN wheels. In addition, the ground surface roughness of porous aggregated cBN wheels ranges from 0.76 to 1.19 μm, whilst the other one possesses over 1.65 μm. Furthermore, the worse ground surface quality is obtained, resulting from the smaller chip storage space and poor self-sharpening ability of vitrified monocrystalline cBN wheels compare to porous aggregated cBN wheels.