Research on Ultra-Precision Machining Technology for KTP

2004 ◽  
Vol 471-472 ◽  
pp. 473-476 ◽  
Author(s):  
Ju Long Yuan ◽  
Fei Yan Lou ◽  
Zhi Wei Wang ◽  
M. Chang ◽  
W.P. Du ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Frequency Conversion ◽  
Removal Rate ◽  
Nonlinear Coefficient ◽  
Damage Threshold ◽  
Green Laser ◽  
Machining Process ◽  
Polished Surface ◽  
Nonlinear Frequency ◽  
Ultra Precision

Potassium Titanium Oxide Phosphate (KTP) is a new nonlinear frequency-conversion crystal. It has chemical stability, high nonlinear coefficient, high damage threshold, easily-polished surface, and a broad transparency range. It is be used in solid green laser with medium and low power widely. The requirement for surface roughness is less than 1nm.In this paper, the removal rate and surface roughness are discussed with different velocity, pressure and size of abrasive powder. In order to satisfy the requirement, new polishing techniques with ultra-precision plane polishing machine (Nanopoli-100), and fine AL2O3, SiO2 powders are proposed in this study. The final surface roughness of the KTP is less than 1nm.The machining process and characteristics are also indicated.

Effect of Frequency to Ultrasonic Vibration-Assisted Wire-EDM

2019 ◽  
Vol 814 ◽  
pp. 127-131
Author(s):  
Patittar Nakwong ◽  
Apiwat Muttamara
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Electrical Discharge Machine ◽  
Machining Process ◽  
Wire Electrode ◽  
Ultrasonic Machine ◽  
Lower Amplitude ◽  
Wedm Process

Wire electrical discharge machine (WEDM) is non-conventional machining process. It can be used for hard cutting material. The study has been presented the combining WEDM with an ultrasonic machine (USM) with brass and tungsten were used as a wire electrode and workpiece respectively. The experiment was carried out with an ultrasonic transducer at 40, 80 kHz. The results were observed with the material removal rate (MRR) and surface roughness (Ra). This research introduced the method of USM setup and described the effected of vibration with the wire electrode on the displacement of amplitude. The result shows that the WEDM process with USM at 40 kHz can be more improved with the material removal rate and surface roughness than that of USM at 80 kHz. This can be explained that higher frequency affected to vibration displacement which makes lower amplitude.

Fundamental Studies on the Mechanisms of Oxide CMP

2000 ◽  
Vol 613 ◽  
Author(s):  
Uday Mahajan ◽  
Seung-Mahn Lee ◽  
Rajiv K. Singh
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Wear Rate ◽  
Removal Rate ◽  
Polished Surface ◽  
Electrostatic Repulsion ◽  
Polishing Process ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Slurry Stability

ABSTRACTIn this paper, results of studies on the addition of salt to a polishing slurry, in terms of its effect on slurry stability, SiO2 polishing rate and surface roughness of the polished surface are presented. Three salts, viz. LiCl, NaCl and KCl were selected, and three concentrations were tested. Polishing rate measurements using these slurries show that adding salt leads to increased removal rate without affecting surface roughness significantly. Based on these results, we can say that the agglomerates formed by adding salt to the slurry are fairly soft and easily broken during the polishing process. In addition, turbidity and particle size measurements show that significant coagulation of the particles in the slurry occurs only at the highest salt concentration, and is fastest for LiCl and NaCl, with KCl showing the slowest coagulation. From these results, it can be concluded that the enhancement in polish rate is due to increased contact at the wafer-pad-slurry interface, and not due to formation of larger agglomerated particles in the slurry. This is because of reduced electrostatic repulsion between these three surfaces, due to the screening of their negative surface charge by the metal ions in solution, resulting in a higher wear rate.

Comparison of Processing Features between Semi Bonded Abrasive Lapping and Loose Abrasive Lapping

2009 ◽  
Vol 416 ◽  
pp. 439-442
Author(s):  
Xun Lv ◽  
Ju Long Yuan ◽  
Dong Hui Wen
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Processing Parameters ◽  
Good Surface ◽  
Ultra Precision ◽  
New Processing ◽  
Short Time

Semi bonded abrasive lapping is an effective ultra-precision lapping method. It can obtain good surface quality of workpiece in short time. This paper focused on the differences of processing features by comparing semi bonded abrasive lapping and loose abrasive lapping in several groups processing parameters. The results showed that the surface roughness of workpiece in semi bonded abrasive lapping was far superior to that of loose abrasive lapping in same processing parameters. And the MRR (material removal rate) of semi bonded abrasive lapping was slightly lower than that of loose abrasive lapping. For these features of semi bonded abrasive, a new processing flow would also be proposed in this paper.

scholarly journals An Experimental Study on the Precision Abrasive Machining Process of Hard and Brittle Materials with Ultraviolet-Resin Bond Diamond Abrasive Tools

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 125 ◽  
Author(s):  
Lei Guo ◽  
Xinrong Zhang ◽  
Shibin Chen ◽  
Jizhuang Hui
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Manufacturing Process ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Process ◽  
Abrasive Machining ◽  
Machining Performance ◽  
Machined Surface ◽  
Ultraviolet Curable

Ultraviolet-curable resin was introduced as a bonding agent into the fabrication process of precision abrasive machining tools in this study, aiming to deliver a rapid, flexible, economical, and environment-friendly additive manufacturing process to replace the hot press and sintering process with thermal-curable resin. A laboratory manufacturing process was established to develop an ultraviolet-curable resin bond diamond lapping plate, the machining performance of which on the ceramic workpiece was examined through a series of comparative experiments with slurry-based iron plate lapping. The machined surface roughness and weight loss of the workpieces were periodically recorded to evaluate the surface finish quality and the material removal rate. The promising results in terms of a 12% improvement in surface roughness and 25% reduction in material removal rate were obtained from the ultraviolet-curable resin plate-involved lapping process. A summarized hypothesis was drawn to describe the dynamically-balanced state of the hybrid precision abrasive machining process integrated both the two-body and three-body abrasion mode.

A Novel Tape and Diamond Process Developed for Polishing Hard Substrates

2015 ◽  
Vol 656-657 ◽  
pp. 416-421
Author(s):  
Rong Hwei Yeh ◽  
T.M. Chao ◽  
Cheng Kuo Lee ◽  
A.H. Tan
Keyword(s):  
Surface Roughness ◽  
Removal Rate ◽  
Lower Surface ◽  
Polished Surface ◽  
Closed Chamber ◽  
Glass Substrates ◽  
Nominal Size ◽  
Hard Glass ◽  
High Removal Rate ◽  
Diamond Abrasive

A nanoscale polish process with improved desired characteristics of low roughness and low scratch counts has been developed using a novel polish tape and diamond abrasive on hard glass substrates. For an improved polishing performance with high removal rate properties and preventing scratches, a novel tape was developed having a nanofiber level, densified surface and a flatter surface by slenderizing the fiber and dispersing ultrafine fiber using an innovative technique. Using this novel polishing tape with a fiber size of 200nm, one can produce a 17% lower surface roughness (Ra) (from 1.05A to 0.87A) and a reduced polished surface scratch count of 53 reduced to 18. The novel nanocluster diamond abrasive is synthesized from carbon atoms of explosives created by detonation in a closed chamber under an oxygen leaked atmosphere ambient. Several crystals are bonded together by layers of non-diamond carbon and other elements, forming aggregates with a nanocluster structure. Using this novel nanocluster diamond along with an ultra-fine diamond mixture with a nominal size of 15nm, one is able to produce an improvement of a 48% lower surface roughness Ra (from 0.87A to 0.45A) and a lower polishing surface scratch count reduced from 18 to 7. Overall, these results indicate that a smoother and a reduced scratch polished substrate results in a significant improvement in disk defects and related magnetic performances.

The Performance and Optimization of Slurry on the Double Sided Polishing Process of Silicon Wafer

2007 ◽  
Vol 359-360 ◽  
pp. 324-328
Author(s):  
Wei Li ◽  
Gang Xiang Hu ◽  
Xiao Dong Hu ◽  
Xiao Zhen Hu
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Process Parameters ◽  
Ph Value ◽  
Removal Rate ◽  
Polished Surface ◽  
Polishing Process ◽  
Stock Removal

This study compares the effectiveness of different polishing slurries for Double Sided Polishing process of Silicon wafer in the polished surface roughness and stock removal rate, discusses the mechanism of Double Sided Polishing for silicon wafer with different type slurries, also the influence of the pH value, temperature and concentration of the slurries are discussed in this paper. Furthermore, by the optimization of the process parameters, the ultra-smooth of polished surface of silicon wafer has been got with higher efficient.

Optimising the Process Conditions in Ultra-Precision Grinding to Achieve Surface Finish of Optical Quality

2006 ◽  
Vol 304-305 ◽  
pp. 8-13 ◽  
Author(s):  
T. Jin ◽  
D.J. Stephenson
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Material Removal ◽  
Removal Rate ◽  
Optical Quality ◽  
Process Conditions ◽  
Low Alloy Steel ◽  
Optical Surface ◽  
Precision Grinding ◽  
Ultra Precision

Optical surface finish below Ra 10nm can be achieved on a ‘Tetraform C’ grinder of ultra-high stiffness, when grinding a low alloy steel with or without the help of ELID (electrolytic in process dressing). Surface roughness generation modelling has been carried out to predict thepossible surface roughness values. Efforts have been made to transfer the process knowledge to different grinding mode using a rigid 5-axis Edgetek CNC grinder. The effects of material removal rate and grit size and also that of spark out passes on the surface roughness generated have been investigated.

Optimization of Process Parameters on Ti-6Al-4V Using Central Composite Design Method

2011 ◽  
Vol 189-193 ◽  
pp. 1393-1400 ◽  
Author(s):  
M.M. Rahman
Keyword(s):  
Surface Roughness ◽  
Wear Rate ◽  
Process Parameters ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Process ◽  
Peak Current ◽  
Long Pulse ◽  
Pulse On Time

Electrical discharge machining (EDM) is relatively modern machining process having distinct advantages over other machining processes and able to machine Ti-alloys effectively. This paper attempts to investigate the effects of process parameters on output response of titanium alloy Ti-6Al-4V in EDM utilizing copper tungsten as an electrode and positive polarity of the electrode. Mathematical models for material removal rate (MRR), electrode wear rate (EWR) and surface roughness (SR) are developed in this paper. Design of experiments method and response surface methodology techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through analysis of variance. It can be seen that as the peak current increases the TWR decreases till certain ampere and then increases. The excellent surface finish is investigated in this study at short pulse on time and in contrast the long pulse duration causes the lowest EWR. Long pulse off time provides minimum EWR and the impact of pulse interval on EWR depends on peak current. The result leads to wear rate of electrode and economical industrial machining by optimizing the input parameters. It found that the peak current, servo voltage and pulse on time are significant in material removal rate and surface roughness. Peak current has the greater impact on surface roughness and material removal rate.

scholarly journals Cutting Parameter Optimization in Finishing Milling of Ti-6Al-4V Titanium Alloy under MQL Condition using TOPSIS and ANOVA Analysis

2021 ◽  
Vol 11 (1) ◽  
pp. 6775-6780
Author(s):  
V. C. Nguyen ◽  
T. D. Nguyen ◽  
D. H. Tien
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Titanium Alloys ◽  
Contact Area ◽  
Removal Rate ◽  
Multiple Criteria Decision Making ◽  
Machining Process ◽  
Anova Analysis ◽  
Wide Range ◽  
Cutting Parameter Optimization

Titanium and its alloys give immense specific strength, imparting properties such as corrosion and fracture resistance, making them the right candidate for medical and aerospace applications. There is a wide range of engineering applications that use titanium alloys in a variety of forms. The cost of these alloys is slightly higher in comparison to other variants due to the problematic extraction of the molten process. To reduce costs, titanium alloy products could be made by casting, isothermal forging, radial swaging, or powder metallurgy, although these techniques require some kind of finishing machining process. Titanium and its alloys are difficult to machine due to skinny chips leading to a small cutting tool-workpiece contact area. The thermal conductivity of titanium alloys is too low and the stress produced is too large due to the small contact area, which results in very high cutting temperatures. This paper deals with the experimental study of the influence of the Minimum Quantity Lubricant (MQL) environment in the milling of Ti-6Al-4V alloy considering the optimization of surface roughness and production rate. Taguchi-based TOPSIS and ANOVA were used to analyze the results. The experimental results show that MQL with vegetable oil is successfully applied in the milling of Ti-6Al-4V. The research confirms the suitability of TOPSIS in solving the Multiple Criteria Decision Making (MCDM) issue, by choosing the best alternative at Vc=120m/min, fz=0.065mm/tooth, and ap=0.2mm, where the surface roughness and material removal rate are 0.41µm and 44.1492cm3/min respectively. Besides, ANOVA can be used to predict the best parameters set in the milling process based on the regression model. The parameters predicted by ANOVA analysis do not coincide with any implemented parameters

scholarly journals Tool Wear Rate Prediction by using Optimization Techniques

2019 ◽  
Vol 9 (2) ◽  
pp. 1271-1277
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Optimization Techniques ◽  
Machining Process ◽  
Machining Parameters ◽  
Tungsten Carbides ◽  
Electro Discharge Machining ◽  
Pulse On Time

Electro discharge machining is a non-traditional machining process used for machining hard-to-machine materials, such as various grades of titanium alloys, heat-treated alloy steels, composites, tungsten carbides, and so forth. These materials are hard to machine with customary machining procedures like drilling, milling and hence electro-discharge machining is used to machine such materials to get better quality and efficiency. These materials are generally utilized in current industries like die making industries, aeronautics, nuclear industries, and medical fields. This type of machining is thermalbased, and machining takes place due to repetitive electric sparks that generate between workpiece and tool. Both tools and workpieces are inundated in a dielectric liquid, which has two primary functions. In the first place, it behaves like a medium between the work metal and the tool. Second, it is a flushing agent to expel the machined metal from the machined zone. Machining parameters like a pulse on time, current, wire feed the tool and gap voltage affect the output responses like surface roughness and material removal rate. The material removal rate is a significant parameter that determines machining efficiency. Surface roughness is also a vital parameter that decides machining quality. A lot of research has been conducted to determine the optimum parameters for obtaining the best results. In the present work, a comprehensive review of different types of EDM and the effect of various machining parameters on the surface roughness, material removal rate, and other response parameters has been done.

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