Experimental study on subsurface damage of BK7 optical glass grinding with abrasive ordered wheel

Wu Yaqi; Wang Wei; Yang Zhibo; Guo Qiang; Luo Chenxu; Zhang Yuqi

doi:10.16186/j.cnki.1673-9787.2023020006

Abstract：Objectives This study aims to investigate the impact of the optimized arrangement of abrasive grains on the subsurface damage of BK7 optical glass during grinding with diamond wheels.Using the maxi-mum crack depth as an evaluation index,the effects of different grain arrangement methods,grain sizes,and maximum cutting thicknesses of single abrasive grains on the subsurface damage depth of optical glass materials were studied.Methods The study conducted grinding experiments on BK7 optical glass using dia-mond wheels with an orderly arrangement of abrasive grains.Initially,the genetic algorithm was used to op-timize the arrangement of abrasive grains.Afterwards,grinding wheels were manufactured using this opti-mized method,and grinding experiments were carried out with two different particle sizes(40/45 mesh and 120/140 mesh),with varying wheel speeds,worktable feed rates,and grinding depths as experimental con-ditions.A vertical machining center was used for grinding experiments,and the grinding process was mea-sured and analyzed.Results Through the genetic algorithm,the optimal arrangement of the grinding wheel abrasive grains was that the axial distance K was 2 mm,the circumferential spacing ƒ was 0.3 mm,and the arrangement angle α was 50°.The experimental results showed that the optimized arrangement of abra-sive grains in the grinding wheel resulted in a smaller crack depth in the ground BK7 optical glass com-pared to other arrangement methods.The subsurface damage depth decreased with the increase of grain size and increased with the increase of the maximum cutting thickness of abrasive grains.The subsurface dam-age of BK7 optical glass after grinding was observed using section polishing and scanning electron micros-copy,and the subsurface damage values were calculated using Image-Pro Plus 6.0 software.Conclusions The study concluded that the use of an optimized arrangement of abrasive grains can significantly reduce the subsurface damage depth of BK7 optical glass.This indicated that the diamond wheel with an orderly ar-rangement of abrasive grains had a significant effect on improving the grinding quality of optical glass,which had important practical application value for the efficient and high-quality grinding of optical compo-nents.