Relationship between subsurface damage depth and surface roughness during grinding of optical glass with diamond tools

1987 ◽  
Vol 26 (13) ◽  
pp. 2491 ◽  
Author(s):  
P. Paul Hed ◽  
David F. Edwards
2013 ◽  
Vol 21 (25) ◽  
pp. 30433 ◽  
Author(s):  
P. Blaineau ◽  
R. Laheurte ◽  
P. Darnis ◽  
N. Darbois ◽  
O. Cahuc ◽  
...  

2021 ◽  
Author(s):  
Jianzhang Xiao ◽  
Guifeng Wang ◽  
Hang Su ◽  
Pengcheng Huang ◽  
Zhongzhe Chen

Abstract In the paper, a three-dimensional (3D) micromechanical finite element (FE) cutting model with three phases was developed to study the surface integrity of CFRP composites. The surface roughness and the depth of subsurface damage were predicted by using the FE cutting model, which were used to characterize the surface integrity. The machined surface observations and surface roughness measurements of CFRP composites at different fiber orientations were also performed for model validation. It is indicated that the 3D micromechanical model is capable of precisely predicting the surface integrity of CFRP composites. To investigate the complex coupling influences of multiple machining parameters on the surface integrity, the factor analysis of multiple machining parameters was performed, and then the effects of these machining parameters on the surface roughness and subsurface damage depth were obtained quantitatively. It was found that the fiber orientation angle and cutting speed are the most significant factors affecting the surface roughness, and the fiber orientation and edge radius are the main factors affecting the subsurface damage depth. The results also reveal that coupling effects of depth of cut and edge radius should be considered for improving the surface integrity of CFRP composites.


2017 ◽  
Vol 872 ◽  
pp. 19-24
Author(s):  
Zong Chao Geng ◽  
Shang Gao ◽  
Ren Ke Kang ◽  
Zhi Gang Dong

Quartz glass is a typical hard and brittle material. During the manufacturing process of quartz glass components, ultra-precision grinding is widely used due to its high throughput and good dimensional accuracies. However, grinding will unavoidably induce large surface and subsurface damage. In this study, the surface and subsurface damage characteristics of quartz glass substrates ground by diamond wheels with different grit sizes were investigated in terms of surface roughness, surface topography, subsurface microcrack characteristic, and subsurface damage depth. Discussion was also provided to explore corresponding reasons of surface and subsurface damage induced by diamond grinding wheels with different grit sizes of #1500 and #2000. The experiment results showed that the surface roughness, surface damage, and subsurface damage depth induced by #2000 quartz glass was ground by #1500 diamond grinding wheel, and in ductile mode when ground by #2000 diamond grinding wheel.


Author(s):  
XH Lin ◽  
XL Ke ◽  
H Ye ◽  
CL Hu ◽  
YB Guo

The surface/subsurface integrity and grinding force formed during grinding processes of have been researched on BK7 glass using a surface grinder with diamond grinding wheel. The values of surface roughness, subsurface damage and grinding force were measured and the morphology of surface roughness, and subsurface damage were observed with different grinding parameters. The experimental results show that the values of surface roughness, subsurface damage and grinding force increase with the increasing of feed rate and grinding depth and decreasing of wheel speed. The effects trend of grinding parameters on surface roughness, subsurface damage and grinding force are almost the same and the normal grinding force have great influence on surface roughness and subsurface damage, which agree well with theoretical analysis. These relationships can serve as a useful method for non-destructively predicting subsurface damage depth and a theoretical basis for proposing the appropriate grinding parameters to obtain better surface/subsurface integrity and high efficiency.


2013 ◽  
Author(s):  
P. Blaineau ◽  
R. Laheurte ◽  
P. Darnis ◽  
N. Darbois ◽  
O. Cahuc ◽  
...  

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 365
Author(s):  
Wei Yang ◽  
Yaguo Li

Subsurface damage (SSD) produced in a grinding process will affect the performance and operational duration of single-crystal silicon. In order to reduce the subsurface damage depth generated during the grinding process by adjusting the process parameters (added), experiments were designed to investigate the influence of machining factors on SSD. This included crystal orientation, diamond grit size in the grinding wheel, peripheral speed of the grinding wheel, and feeding with the intention to optimize the parameters affecting SSD. Compared with isotropic materials such as glass, we considered the impact of grinding along different crystal directions <100> and <110> on subsurface damage depth (added). The Magnetorheological Finishing (MRF) spot technique was used to detect the depth of SSD. The results showed that the depth of SSD in silicon increased with the size of diamond grit. SSD can be reduced by either increasing the peripheral speed of the grinding wheel or decreasing the feeding rate of the grinding wheel in the <100> crystal orientation, if the same size of diamond grit was employed. In addition, we proposed a modified model around surface roughness and subsurface crack depth, which considered plastic and brittle deformation mechanisms and material properties of different crystal orientations. When the surface roughness (RZ) exceeded the brittle-plastic transition’s critical value RZC (RZC<100> > 1.5 μm, RZC<110> > 0.8 μm), cracks appeared on the subsurface. The experimental results were consistent with the predicted model, which could be used to predict the subsurface cracks by measuring the surface roughness. However, the model only gives the approximate range of subsurface defects, such as dislocations. The morphology and precise depth of plastic deformation subsurface defects, such as dislocations generated in the fine grinding stage, needed to be inspected by transmission electron microscopy (TEM), which were further studied.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 460
Author(s):  
Canbin Zhang ◽  
Chifai Cheung ◽  
Benjamin Bulla ◽  
Chenyang Zhao

Ultrasonic vibration-assisted cutting (UVAC) has been regarded as a promising technology to machine difficult-to-machine materials such as tungsten carbide, optical glass, and hardened steel in order to achieve superfinished surfaces. To increase vibration stability to achieve optical surface quality of a workpiece, a high-frequency ultrasonic vibration-assisted cutting system with a vibration frequency of about 104 kHz is used to machine spherical optical steel moulds. A series of experiments are conducted to investigate the effect of machining parameters on the surface roughness of the workpiece including nominal cutting speed, feed rate, tool nose radius, vibration amplitude, and cutting geometry. This research takes into account the effects of the constantly changing contact point on the tool edge with the workpiece induced by the cutting geometry when machining a spherical steel mould. The surface morphology and surface roughness at different regions on the machined mould, with slope degrees (SDs) of 0°, 5°, 10°, and 15°, were measured and analysed. The experimental results show that the arithmetic roughness Sa of the workpiece increases gradually with increasing slope degree. By using optimised cutting parameters, a constant surface roughness Sa of 3 nm to 4 nm at different slope degrees was achieved by the applied high-frequency UVAC technique. This study provides guidance for ultra-precision machining of steel moulds with great variation in slope degree in the pursuit of optical quality on the whole surface.


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