A Survey of the Machining Characteristics and Mechanical Polishing Technology of CVD Diamond Films

2009 ◽  
Vol 69-70 ◽  
pp. 192-197
Author(s):  
Li Zhang ◽  
Dong Hui Wen ◽  
Shi Ming Ji ◽  
Qiao Ling Yuan ◽  
Zhen Hao Xu
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Removal Rate ◽  
Diamond Films ◽  
Surface Characteristics ◽  
Cvd Diamond ◽  
Mechanical Polishing ◽  
Polishing Process ◽  
Machining Characteristics ◽  
Processing Mechanism

The rough surfaces and non-uniform thicknesses of chemically vapor-deposited (CVD) diamond films and substrates affect their industrial application. In recent years, many polishing and planarization methods have been reported, but each method has its relative merits. This paper reviews the necessity for processing of the CVD diamond films first. Then the processing mechanism of micro-cracking and the characteristics of mechanical polishing of diamond films are discussed. The remove form of the material and surface characteristics are compared by three mechanical polishing method, including free abrasive polishing, fixation abrasive polishing and membrane on the membrane polishing method. No matter what form of mechanical polishing process is adopted, because of its inherent characteristics and the principles of processing, mechanical polishing CVD diamond films can only be as polish processing to remove large residual. The macro-surface roughness of processing is about the 2μm. The micro-rough surface roughness is for the 40nm or so. The material removal rate is 10nm/h.

EDM with USM Combination Process of Sintered NdFeB Permanent Magnet

2010 ◽  
Vol 44-47 ◽  
pp. 1066-1069
Author(s):  
Li Li ◽  
Li Ling Qi ◽  
Zong Wei Niu
Keyword(s):  
Permanent Magnet ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Dielectric Fluid ◽  
Machined Surface ◽  
Combination Process ◽  
Electro Discharge Machining ◽  
Ndfeb Permanent Magnet ◽  
Machining Characteristics

This paper presents an experimental investigation of the machining characteristics of sintered NdFeB permanent magnet using a combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). Concentration of abrasive in the dielectric fluid is changed to explore its effect on the material removal rate (MRR). MRR of EDM /USM, conventional EDM are compared, machined surface characteristics are also compared between them. It is concluded that the combination EDM/USM process can increase the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate abrasive concentration can improve its machining efficiency.

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.

Multi Response Optimization of Process Parameters of Abrasive Water Jet Machining for Stainless Steel AISI 304 Using VIKOR Approach Coupled with Signal to Noise Ratio Methodology

2015 ◽  
Vol 14 (02) ◽  
pp. 107-121 ◽  
Author(s):  
Vedansh Chaturvedi ◽  
Diksha Singh
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Aisi 304 ◽  
Steel Aisi ◽  
Machining Characteristics ◽  
Stainless Steel Aisi ◽  
Experimental Runs

As the population of the world is continuously increasing, demand of the mechanical manufactured products is also increasing. Machining is the most important process in any mechanical manufacturing, and in machining two factors, i.e. material removal rate (MRR) and surface roughness (SR) are the most important responses. If the MRR is high, the product will get desired shape in minimum time so the production rate will be high, but we could not scarify with the surface finishing also because in close tolerance limit parts like in automobile industry, if the surface is rough exact fit cannot take place. The term optimization is intensively related to the field of quality engineering. Abrasive water jet machining is an important unconventional machining, in order to obtain better response, i.e. material removal rate and surface roughness. Various process parameters of AWJM need to be observed and selected to improve machining characteristics. Better machining characteristics can be achieved by optimizing various process parameters of AWJM. This study considers four process control parameters such as transverse speed, standoff distance, abrasive flow rate and water pressure. The response is taken to be material removal rate and surface roughness. The work piece for stainless steel AISI 304 material of size 15 cm × 10 cm × 2 cm is selected for experiments. Sixteen experimental runs (two trials for each experimental runs) were carried out for calculating MRR and SR and average value of these two trials have been taken for analysis. MRR is normalized according to higher-is-better and SR is normalized according to lower is better. The experiment data analysis is done and VIKOR index is found. Finally, the analysis of VIKOR index using S/N ratio is done and found the most significant factor for AWJM and predicted optimal parameters setting for higher material removal rate and lower surface roughness. Verification of the improvement in quality characteristics has been made through confirmation test with the predicted optimal parameters setting. It is found that the determined optimum combination of AWJM parameters gives the lowest VIKOR INDEX which shows the successful implementation of VIKOR Method coupled with S/N ratio in AWJM.

scholarly journals Comparative Analysis of Machining Characteristics of EDM and ECM during Machining of Ti-6Al-4V

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Banwait S.S. ◽  
◽  
Sanjay S ◽  
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Electric Discharge ◽  
Material Removal ◽  
Removal Rate ◽  
Electric Discharge Machining ◽  
Pulse On Time ◽  
Surface Finish Effect ◽  
Machining Characteristics

The present work explains the machining of Titanium alloy using Electric Discharge Machining & Electro-Chemical Machining. This work aims to analyze the role of Current, Pulse on Time, Voltage and hence optimize the Material Removal Rate and Surface Roughness in Electric Discharge Machining. In the same way, it also aims to analyze the role of Concentration, Feed, and Voltage and optimize the Material Removal Rate and Surface Roughness in Electro-Chemical Machining. The various approaches like Taguchi & Analysis of Variance are executed to study the performance characteristics of the input parameters on the output parameters. The whole work is followed by a validation test and hence confirming the obtained values. Thus, it reveals the acceptability of the model. The work tells that Material Removal Rate and Surface Finish effect is more in Electro-Chemical Machining as compared to Electric Discharge Machining. For Material Removal Rate, Current and Feed are more responsible parameters for Electric Discharge Machining. In the same way; electrolyte concentration and Feed are more responsible parameters for Electro-Chemical Machining respectively.

Analysis on the Influence of Oxidant in CMP of Ultra-Thin Stainless Steel

2014 ◽  
Vol 1027 ◽  
pp. 167-170 ◽  
Author(s):  
Jian Xiu Su ◽  
Jia Peng Chen ◽  
Hai Feng Cheng ◽  
Song Zhan Fan
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
304 Stainless Steel ◽  
Research Results

In chemical mechanical polishing (CMP) of ultra-thin stainless steel, the oxidant of polishing slurry determines the material removal rate (MRR). In this paper, the influences of oxidant in slurry on MRR and surface roughness have been studied in CMP of ultra-thin 304 stainless steel based on alumina (Al2O3) abrasive. The research results show that, in the same conditions, the MRR increases with the increase of the oxidant C and the oxidant B, the MRR decreases with the increase of the oxidant A and the MRR is max with the oxidant C. It indicated that the oxidant C has a large effect on MRR in CMP of the 304 stainless steel. The research results can provide the reference for studying the slurry in CMP of ultra-thin stainless steel.

Principle and Experiment of Ultrasonic Subtle Atomization in CMP

2011 ◽  
Vol 279 ◽  
pp. 287-290 ◽  
Author(s):  
Xiao Peng Liu ◽  
Xiao Chun Chen ◽  
Qing Zhong Li
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Experimental System ◽  
Mechanical Polishing

The method of chemical mechanical polishing (CMP) using slurry which was ultrasonic subtle atomized was researched, and the system of Ultrasonic Subtle Atomization—Chemical Mechanical Polishing was established. The effects of polish parameters on polishing were also investigated. The results show that the experimental system can fully realize the expected function of polishing, the use of slurry is about one-tenth of the amount of traditional CMP, material removal rate can reach 113.734nm/min and the surface roughness is similar to the surface roughness in the traditional way.

Effects of Magnetic Fluid on Machining Characteristics in Magnetic Field Assisted Polishing Process

2013 ◽  
Vol 797 ◽  
pp. 396-400
Author(s):  
Shao Hui Yin ◽  
Zhi Qiang Xu ◽  
Hong Jie Duan ◽  
Feng Jun Chen
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Magnetic Fluid ◽  
Material Removal ◽  
Magnetorheological Fluid ◽  
Magnetic Fluids ◽  
Magnetic Characteristics ◽  
Polishing Process ◽  
Magnetic Cluster ◽  
Machining Characteristics

Magnetic characteristics of three magnetic polishing fluids such as magnetic fluid (MF), magnetorheological fluid (MRF), and magnetic compound fluid (MCF) under magnetic field are experimentally investigated and analyzed. Their magnetic cluster structures under action of magnet field are observed, and their magnetic cluster models are established. Magnetic flied assisted polishing experiments for tungsten carbide are developed used these three kinds of magnetic fluids, material removal and surface roughness are respectively measured. At last, the machining characteristic of three magnetic fluids are contrasted and discussed according to experimental results.

Chemical Mechanical Polishing Slurries for Chemically Vapor-Deposited Diamond Films

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Zewei Yuan ◽  
Zhuji Jin ◽  
Youjun Zhang ◽  
Quan Wen
Keyword(s):  
Potassium Permanganate ◽  
Surface Finish ◽  
Diamond Film ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Mechanical Polishing ◽  
Potassium Ferrate ◽  
Cvd Diamond Film

The objective of this study is to investigate slurries for chemical mechanical polishing (CMP) of chemically vapor-deposited (CVD) diamond films based on the principle of thermokinetics combined with physical and chemical properties. The study uses the mechanical work, surface energy and oxidability of a slurry with diamond carbon as the main physical-chemical indicators in selecting the slurries. The study indentifies 10 CMP slurries of different oxidants, such as potassium ferrate, potassium permanganate, chromium trioxide and potassium dichromate, for CVD diamond film polishing. Prior to a CMP process, prepolishing with a boron carbide plate is performed to prepare a CVD diamond film with acceptable surface finish and flatness. After polishing with the CMP process a CVD diamond film is examined with optical microscopy, surface profilometry, atomic force microscopy and X-ray photoelectron spectroscopy for information on surface finish and quality, material removal and mechanisms. The study demonstrates that among the ten CMP slurries, the one with potassium ferrate as an oxidant provides the highest material removal rate of 0.055 mg/hour, and the best surface finish (Ra = 0.187 nm) and surface quality (no surface scratches nor pits), which is followed by potassium permanganate. It then discusses how mechanical stress may promote the chemical oxidation of an oxidant with diamond by forming “C-O” and “C=O” on diamond surface. The study concludes that chemical mechanical polishing is effective for CVD diamond films.

Effect of Operated Parameters on Removal Rate and Surface Roughness in Precision Atomization Ultra-Polishing Process of Copper Surface

2011 ◽  
Vol 189-193 ◽  
pp. 4141-4144 ◽  
Author(s):  
Qing Zhong Li ◽  
Yong Guang Wang ◽  
Zhi Xue Guo ◽  
Dong Ming Guo
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Atmospheric Pressure ◽  
Material Removal ◽  
Removal Rate ◽  
Copper Surface ◽  
The Novel ◽  
Optimal Parameters ◽  
Polishing Process ◽  
Insight Into

Compared with the traditional chemical mechanical polishing (CMP) technique, the precision atomization ultra-polishing (PAUP) technology has the advantages of friendly environmental and damage-free. This paper established a novel PAUP tester based on the atmospheric pressure theory, and explored the possibility of PAUP technique. Furthermore, effects of operated parameters on the material removal rate and surface roughness were investigated in PAUP process. It was found that a material removal rate of 78.302 nm/min was obtained with a surface roughness of 0.015 µm at the optimal parameters. This study provides insight into the development of the novel ultra-polishing methods and its underlying theoretical foundation.

Chemical-Assisted Mechanical Polishing of Diamond Film on Wafer

2006 ◽  
Vol 505-507 ◽  
pp. 1225-1230 ◽  
Author(s):  
Hong Ho Cheng ◽  
C.C. Chen
Keyword(s):  
Surface Roughness ◽  
Potassium Permanganate ◽  
Diamond Film ◽  
Removal Rate ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Industrial Applications ◽  
Potassium Persulfate ◽  
Ceramic Plate ◽  
Cvd Diamond Film

Diamond has been well recognized a strategic engineering material. It possesses excellent physical and chemical properties including the highest hardness and thermal conductivity, and good resistance to chemical erosion. Although CVD diamond film has good potential outstanding properties, its industrial applications have been limited by the non-uniform thickness and rough surface. In the current study, the CVD diamond film is polished by the chemical-assisted mechanical method with different slurries. These slurries contain strong oxidation chemical and diamond powder. During the process, the diamond film was held against the rotational ceramic plate with transverse oscillation at 90 °Cor lower. The profilometer, atomic force microscope and scanning electron microscope were used to evaluate the surface integrity of the diamond films before and after polishing. Based on the experimental results, the slurry containing potassium persulfate (K2S2O8) produces the highest material removal rate while potassium permanganate (KMnO4) develops the best local surface roughness. The strategy of using potassium persulfate for coarse polishing followed by potassium permanganate for fine polishing yields the diamond films of the best global surface roughness. The average surface roughness of the diamond film produced by the proposed technique is below 10 nm after 5 hours.

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