Hybrid CO2 laser-polishing process for improving material removal of silicon carbide

2020 ◽  
Vol 106 (7-8) ◽  
pp. 3139-3151 ◽  
Author(s):  
Mincheol Kim ◽  
Sangmin Bang ◽  
Dong-Hyeon Kim ◽  
Hyun-Taek Lee ◽  
Geon-Hee Kim ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Co2 Laser ◽  
Material Removal ◽  
Polishing Process ◽  
Laser Polishing

Investigation on Smoothing Silicon Carbide Wafer With a Combined Method of Mechanical Lapping and Photocatalysis Assisted Chemical Mechanical Polishing

2018 ◽  
Author(s):  
Zewei Yuan ◽  
Kai Cheng ◽  
Yan He ◽  
Meng Zhang
Keyword(s):  
Silicon Carbide ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Combined Method ◽  
Polishing Process ◽  
High Quality ◽  
Quality Surface ◽  
High Quality Surface

The high quality surface can exhibit the irreplaceable application of single crystal silicon carbide in the fields of optoelectronic devices, integrated circuits and semiconductor. However, high hardness and remarkable chemical inertness lead to great difficulty to the smoothing process of silicon carbide. Therefore, the research presented in this paper attempts to smooth silicon carbide wafer with photocatalysis assisted chemical mechanical polishing (PCMP) by using of the powerful oxidability of UV photo-excited hydroxyl radical on surface of nano-TiO2 particles. Mechanical lapping was using for rough polishing, and a material removal model was proposed for mechanical lapping to optimize the polishing process. Several photocatalysis assisted chemical mechanical polishing slurries were compared to achieve fine surface. The theoretical analysis and experimental results indicate that the material removal rate of lapping process decreases in index form with the decreasing of abrasive size, which corresponds with the model developed. After processed with mechanical lapping for 1.5 hours and subsequent photocatalysis assisted chemical mechanical polishing for 2 hours, the silicon carbide wafer obtains a high quality surface with the surface roughness at Ra 0.528 nm The material removal rate is 0.96 μm/h in fine polishing process, which is significantly influenced by factors such as ultraviolet irradiation, electron capture agent (H2O2) and acidic environment. This combined method can effectively reduce the surface roughness and improve the polishing efficiency on silicon carbide and other hard-inert materials.

scholarly journals Modeling and Optimization of Laser Polishing Process

2014 ◽  
Vol 575 ◽  
pp. 766-770 ◽  
Author(s):  
Benoit Rosa ◽  
Jean Yves Hascoet ◽  
Pascal Mognol
Keyword(s):  
Laser Power ◽  
Quadratic Model ◽  
Operating Parameters ◽  
Primary Process ◽  
Initial Surface ◽  
Polishing Process ◽  
Laser Polishing ◽  
Finishing Process ◽  
Optimal Set ◽  
Melting Material

Laser polishing is a finishing process based on melting material, with the objective of improving surface topography. Some operating parameters must be taken into consideration, such as laser power, feed rate, offset, and overlapping. Moreover, because of its dependence on the primary process, the initial topography has also an impact on the final result. This study describes a quadratic model, conceived to optimize final topography according to the primary process and laser polishing. Based on an experimental matrix, the model takes into account both laser operating parameters and the initial topography, in order to predict polished surfaces and to determine optimal set of parameters. After the phase of experimentation and the creation of the quadratic model, an optimal final topography is introduced, taking into account the initial surface and the laser parameters.

Material Removal and Application by Chemical Impact Reaction in Nano-Abrasive Jet Polishing

2013 ◽  
Vol 631-632 ◽  
pp. 550-555
Author(s):  
Wen Qiang Peng ◽  
Sheng Yi Li ◽  
Chao Liang Guan ◽  
Xin Min Shen
Keyword(s):  
Material Removal ◽  
Abrasive Particle ◽  
Precision Machining ◽  
Optical Surface ◽  
Polishing Process ◽  
Abrasive Particles ◽  
Mechanical Process ◽  
Abrasive Jet Polishing ◽  
Ultra Precision ◽  
Machining Properties

Material removed by mechanical process inevitably causes surface or subsurface damage containing cracks, plastic scratch, residual stress or dislocations. In nano-abrasive jet polishing (NAJP) the material is removed by chemical impact reaction. The chemical impact reaction is validated by contrast experiment with traditional lap polishing process in which the material is mainly removed through mechanical process. Experiment results show the dependence of the abrasive particles on the choice of materials. Even if the abrasive particle and the workpiece are composed of similar components, the machining properties are remarkably different due to slight differences in their physical properties or crystallography etc. Plastic scratches on the sample which was polished by the traditional mechanical process are completely removed by NAJP process, and the surface root-square-mean roughness has decreased from 1.403nm to 0.611nm. The NAJP process will become a promising method for ultra precision machining method for ultrasmooth optical surface.

Effects of the Profile of Workpiece Surface on Material Removal Rate Distribution in Polishing Process

2016 ◽  
Vol 851 ◽  
pp. 149-154
Author(s):  
Zhen Gang Wu ◽  
Dong Shan He ◽  
Ping Zhou ◽  
Dong Ming Guo
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Profile ◽  
Prediction Method ◽  
Quantitative Prediction ◽  
Polishing Process ◽  
Workpiece Surface ◽  
Coefficient Distribution ◽  
Polishing Pad

Accurate prediction of the material removal rate (MRR) distribution is very important for the control of the polishing process. However, the widely used prediction method of MRR based on the Preston equation is still incapable of predicting the roll-off phenomenon in polishing process. One of the reasons is that many of the researchers’ neglected the effect of the surface profile of the workpiece on the MRR. In this paper, the evolutionary process of MRR distribution with the change of surface profile using two different polishing pad is studied, it is found that MRR varies gradually with the change of surface profile and tends to be uniform finally. Based on the analysis of contact pressure considering the actual surface profile of workpiece and modified Preston equation, the distribution of MRR is analyzed. It is found that the Preston coefficient distribution on workpiece surface is stable when the surface profile variation is small and shows obvious differences from the center to the edge of the workpiece. Through the comparison it is found that correlation between the regularities of Preston coefficient distribution and the type of polishing pad is significant. The research results in this paper will play an important guiding role in the quantitative prediction method research of polishing process.

scholarly journals Steel mould surface improvement by robot fluid jet polishing and robot pad polishing for polymer optic production

2019 ◽  
Vol 215 ◽  
pp. 05003
Author(s):  
Rui Almeida ◽  
Timon Ebert ◽  
Rainer Börret ◽  
Mario Pohl
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Geometrical Shape ◽  
Polishing Process ◽  
Shape Deviation ◽  
Mould Surface ◽  
Shape Correction ◽  
Steel Mould ◽  
Surface Improvement

In order to improve the quality of injection-moulded polymer optic parts, it is necessary to improve the quality of the respective steel moulds. For this reason, it is not only necessary to improve the surface roughness of the mould, but also its geometrical shape. The material removal obtained from robot pad polishing is too low. This makes a shape correction after the milling step a very prolonged process. The aim of this work is to use a polishing chain to improve the surface quality of steel samples in terms of shape deviation and surface roughness. This correction polishing chain uses the robot fluid jet polishing for the geometrical shape correction and afterwards the robot pad polishing for the improvement of the surface roughness. Due to the high material removal rates of the fluid jet polishing, it is possible to correct the geometrical shape of steel moulds very fast up to a certain deviation. The pad polishing process improves the surface roughness of the steel samples. A correction of the shape deviation of more than 80% with a RMS of approximately 8 nm was obtained.

Material removal characteristics of full aperture optical polishing process

2017 ◽  
Vol 21 (4) ◽  
pp. 493-525 ◽  
Author(s):  
Raj Kumar Pal ◽  
Harry Garg ◽  
Vinod Karar
Keyword(s):  
Material Removal ◽  
Polishing Process ◽  
Optical Polishing

Estimation of the minimum material removal thickness during the polishing process of ceramic tiles by laser triangulation

2018 ◽  
Vol 44 (5) ◽  
pp. 4646-4652 ◽  
Author(s):  
J.E. Soares Filho ◽  
J.C. Aurich ◽  
F.J.P. Sousa ◽  
R.M. Nascimento ◽  
C.A. Paskocimas
Keyword(s):  
Material Removal ◽  
Laser Triangulation ◽  
Ceramic Tiles ◽  
Polishing Process
Sign in / Sign up

Export Citation Format

Share Document