Experimental investigation on grinding characteristics of optical glass BK7: with special emphasis on the effects of machining parameters

Abstract

As a kind of widely used optical material, optical glass BK7 is machined by first grinding and then polishing in industrial production. However, the polishing process is timeconsuming and high-cost. Therefore, it is very meaningful to produce high-quality BK7 workpieces by grinding. To understand the grinding characteristics of BK7, many studies were conducted and reported. But most studies available so far had low industrial relevance and were difficult to be applied to guide real production of BK7 glass. To fill this gap, in this study, BK7 grinding characteristics are investigated and special emphasis is laid on the effects of machining parameters in terms of machined surface morphology, subsurface damage, and grinding force. Results show that wheel depth of cut plays the most important role in BK7 grinding, and a little difference of it leads to completely different material removal modes. Wheel speed is the second important parameter. It cannot change the dominant removal mode but can slightly adjust the characteristics of machined surface, subsurface damage, and grinding force. Workpiece feed rate has a small impact on BK7 grinding. From the viewpoint of industrial application, it suggests that the wheel depth of cut of 1.0 μm, high wheel speed, and high workpiece feed rate are more rational and practical because under this condition the grinding process can produce BK7 workpieces, which possess crack-free surface and sublet subsurface damage, with high removal rates and stable grinding forces. The findings of this paper are expected to be meaningful to provide the experimental references for the studies of the BK7 grinding process and guide industrial production of BK7 optical components.

Effect to the Surface Composition in Ultrasonic Vibration-Assisted Grinding of BK7 Optical Glass

“…A total of 32 groups of experiments were carried out on BK7 optical glass based on this experimental design. 11,000 110 60 7 7 13,000 110 60 7 8 15,000 110 60 7 9 11,000 10 60 7 10 11,000 30 60 7 11 11,000 50 60 7 12 11,000 70 60 7 13 11,000 90 60 7 14 11,000 110 60 7 15 11,000 130 60 7 16 11,000 150 60 7 17 11,000 110 10 7 18 11,000 110 20 7 19 11,000 110 30 7 20 11,000 110 40 7 21 11,000 110 50 7 22 11,000 110 60 7 23 11,000 110 70 7 24 11,000 110 80 7 25 11,000 110 60 0 26 11,000 110 60 1 11,000 110 60 7 7 13,000 110 60 7 8 15,000 110 60 7 9 11,000 10 60 7 10 11,000 30 60 7 11 11,000 50 60 7 12 11,000 70 60 7 13 11,000 90 60 7 14 11,000 110 60 7 15 11,000 130 60 7 16 11,000 150 60 7 17 11,000 110 10 7 18 11,000 110 20 7 19 11,000 110 30 7 20 11,000 110 40 7 21 11,000 110 50 7 22 11,000 110 60 7 23 11,000 110 70 7 24 11,000 110 80 7 25 11,000 110 60 0 26 11,000 110 60 1 27 11,000 110 60 2 28 11,000 110 60 3 29 11,000 110 60 4…”

“…Therefore, the proportion of these removal methods on the machined surface determines the final machined surface quality and subsurface damage. Although studies at home and abroad have been able to control the surface roughness [24][25][26], processing efficiency [27,28], force and energies [29,30] or damages [31] by adjusting the process parameters, for the precision machining of brittle materials that pay attention to the surface quality and subsurface damage at the same time, the intrinsic relationship between the proportion of the material removal modes and the process parameters and the parameters of the grinding wheel is still not clear. The effective control of the material removal modes proportion is the basis and key to exploring the technical measures to jointly improve the processing surface and subsurface quality.…”

The Refractive Index Of Photonic Crystal Fibers As A Function Of Some Parameters And Temperature

“…Refractive index depends on the density and temperature ,the refractive index may specify the dispersive power of the prism, and the power of the lenses or some materials, such as water, may know the purity of the prism determination of the refractive index by changing its concentration [14]. The change in the refractive index with respect to temperature can be described by the relationship [15]: The temperature difference is above standard grade. ∆𝑇 𝜆 )the wavelength of the electromagnetic wave in the vacuum and in units 𝜇𝑚.…”

Cutting Characteristics for Sugar Maple Using Single Grit with Spherical Cone and Triangular Pyramid Geometries

“…Three different shapes of grits (circular, square, and triangular) were manufactured by laser ablation and mounted on a dummy wheel. Yu et al [13] investigated the grinding characteristics of optical glass BK7 experimentally. The single-grit tool was made by a single diamond grit with a triangular pyramid geometry.…”