Improving the Surface Roughness of a CVD Coated Silicon Carbide Disk by Performing Ductile Regime Single Point Diamond Turning

2008 ◽  
Author(s):  
Deepak Ravindra ◽  
John Patten
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Surface Quality ◽  
Removal Rate ◽  
Single Point ◽  
Extreme Environments ◽  
High Hardness ◽  
Diamond Turning ◽  
Ductile Regime Machining

Silicon carbide (SiC) is one of the advanced engineered ceramics materials designed to operate in extreme environments. One of the main reasons for the choice of this material is due to its excellent electrical, mechanical and optical properties that benefit the semiconductor, MEMS and optoelectronic industry respectively. Manufacture of this material is extremely challenging due to its high hardness, brittle characteristics and poor machinability. Severe fracture can result when trying to machine SiC due to its low fracture toughness. However, from past experience it has been proven that ductile regime machining of silicon carbide is possible. The main goal of the subject research is to improve the surface quality of a chemically vapor deposited (CVD) polycrystalline SiC material to be used in an optics device such as a mirror. Besides improving the surface roughness of the material, the research also emphasized increasing the material removal rate (MRR) and minimizing the diamond tool wear. The surface quality was improved using a Single Point Diamond Turning (SPDT) machining operation from 1158nm to 88nm (Ra) and from 8.49μm to 0.53μm (Rz; peak-to-valley).

scholarly journals Rotary Ultrasonic Machining of Alumina Ceramic: An Experimental Investigation of Tool Path and Tool Overlapping

2020 ◽  
Vol 10 (5) ◽  
pp. 1667 ◽  
Author(s):  
Basem M. A. Abdo ◽  
Abdualziz El-Tamimi ◽  
Emad Abouel Nasr
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Surface Quality ◽  
Tool Path ◽  
Removal Rate ◽  
Ultrasonic Machining ◽  
Rotary Ultrasonic Machining ◽  
Roughness Surface ◽  
Tool Wear Mechanisms

Pocket milling has been regarded as one of the most widely used operations in machining. The surface quality of the machined pockets is an essential aspect of any engineering and medical applications. In the current study, rotary ultrasonic machining (RUM) was applied for milling micro-pockets on alumina (Al2O3) ceramic. The objective of this research was to analyze the effect of the tool overlapping parameters on the surface roughness, surface morphology and the profiles of the machined pockets. Subsequently, the effect of different tool path strategies was analyzed on the surface quality and the material removal rate (MRR) of the machined pockets. A scanning electron microscope is used for analyzing the tool wear mechanisms. The experimental results provide evidence that the surface roughness, surface morphology and the MRR have been significantly affected by the considered tool overlapping and the tool path strategies. Furthermore, among the selected tool overlapping parameters (5–25%) and the tool path strategies, the best surface roughness (Ra = 0.155 μm and Rt = 1.432 µm) of the machined pockets can be found at 20% of the tool overlapping with a mix of uni-directional and zigzag tool path strategy.

Fixed Abrasive Lapping and Polishing of Hard Brittle Materials

2010 ◽  
Vol 426-427 ◽  
pp. 589-592 ◽  
Author(s):  
Jun Li ◽  
Yong Wei Zhu ◽  
Dun Wen Zuo ◽  
Kui Lin ◽  
M. Li
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Removal Rate ◽  
Brittle Materials ◽  
Process Conditions ◽  
High Productivity ◽  
Fixed Abrasive ◽  
K9 Glass ◽  
Panel Glass

Fixed abrasive lapping and polishing (FALP) is a new machining technology and was adopted to manufacture hard brittle materials and obtain the high productivity because of fixed abrasive. The preparation process of fixed abrasive pad (FAP) was described. FALP of K9 glass, mobile panel glass and Si were investigated with fixed 5-10 µm diamond abrasives. The effect on material removal rate (MRR) and surface quality of different materials was studied. The results show that in the same FALP process conditions, Si is the highest MRR and reaches 4428 nm/min, mobile panel glass is inferior to and K9 glass is the lowest. And surface quality of mobile panel glass that surface roughness Sa is 2.10 nm and little and less damages is the best, Si is followed and K9 glass is the worst. So FALP can obtain the higher MRR and reaches several micrometers per minute and the better quality that surface roughness Sa can reach nanometer level for different materials.

A Study of Cutting Strategy in Single-Point Diamond Turning of Micro V-Groove Patterns on Precision Roller Drums

2014 ◽  
Vol 625 ◽  
pp. 742-747
Author(s):  
C.H. Mak ◽  
C.F. Cheung ◽  
M.J. Ren ◽  
L.B. Kong ◽  
S. To
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Cutting Parameters ◽  
Diamond Turning ◽  
Surface Generation ◽  
Depth Of Cut ◽  
Tool Paths ◽  
Cutting Strategy ◽  
Groove Pattern

This paper presents a study of cutting strategies on the surface generation in single-point diamond turning of micro V-groove patterns on precision roller drums. An aluminium precision roller drum with a diameter 250mm and 100 long was diamond turned with a V-groove pattern. A series of cutting experiments were designed to study the effect of the variation of various cutting parameters and cutting tool paths on the surface quality in diamond turning of the precision roller drum. The parameters under investigation included the depth of cut, number of steps and the depth for each cut when diamond turning V-grooves on the cylindrical surface of a workpiece. The measurement result indicates that the surface quality of V-grooves machined on the precision roller drums is affected by cutting strategies. The optimal cutting strategy for machining a V-groove pattern on a precision drum with 5µm depth was obtained.

Ultra-Precision Turning Technology of Gold Cone in Fast Ignition

2013 ◽  
Vol 562-565 ◽  
pp. 147-151
Author(s):  
Guo Li ◽  
Yan Hua Huang ◽  
Wei Chao Tong ◽  
Guang Hui Yuan ◽  
Yang Tao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wall Thickness ◽  
Single Point ◽  
Fast Ignition ◽  
Diamond Turning ◽  
End Effect ◽  
Processing Parameter ◽  
Ultra Precision ◽  
Cone Surface

Fast Ignition (FI) attracts much attention owing to its advantages. The fabrication of fast ignition targets is one of the key technologies in FI study. Based on the single point diamond turning (SPDT) technology, Diamond post-turning method is adopted in this paper for the fabrication of gold cone. It not only helps to reduce the end-effect of cone mandrel and consequently improve the coaxiality of internal and external cone surface, but also helps to improve the quality of cone surface and the wall thickness consistency. Besides, the processing parameter of diamond post-turning is experimentally studied in this paper for its effect on the cone surface roughness. According to results, the cone surface roughness is Ra 9.21nm, the wall thickness consistency is 3μm and the cone end surface roughness is Ra5.72nm。

Effects of Electricity Parameters on Surface Quality of Reaction Bonded Silicon Carbide Ceramic with Electrical Discharge Diamond Grinding

2016 ◽  
Vol 874 ◽  
pp. 15-21 ◽  
Author(s):  
Xiao Shuang Rao ◽  
Fei Hu Zhang ◽  
Chen Li
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Machining Process ◽  
Hybrid Machining ◽  
Micro Cracks ◽  
Sic Ceramic ◽  
Hybrid Machining Process

With some conductivity and low grinding affectivity, a hybrid machining process termed electrical discharge diamond grinding (EDDG) is applied to the precision machining of reaction bonded silicon carbide (RB-SiC) ceramic. As there is electrical spark in the hybrid machining process, the electrical parameters are varied to explore their effects on the surface quality of RB-SiC ceramic with EDDG. In this paper, the experiments of different polarity and gap voltage with EEDG were investigated, and the microstructure and surface roughness on the machined surface of RB-SiC ceramic were analyzed. The surface morphology and micro-cracks were examined with a scanning electron microscope, and the surface roughness was measured with a confocal scanning laser microscope. It is found that surface roughness initially increases and then decreases with increase of the gap voltages and is higher with negative polarity than that with positive polarity. The micromorphology Micro-cracks were observed on the surface machined and are outstanding in re-solidified zone with EDDG.

Machinability Investigation of Reaction-Bonded Silicon Carbide by Single-Point Diamond Turning

2008 ◽  
Vol 389-390 ◽  
pp. 151-156 ◽  
Author(s):  
Zhi Yu Zhang ◽  
Ji Wang Yan ◽  
Tsunemoto Kuriyagawa
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Single Point ◽  
Diamond Turning ◽  
Machining Process ◽  
Depth Of Cut ◽  
Material Microstructure

Reaction-bonded silicon carbide (RB-SiC) is a recently developed ceramic material with many merits such as low manufacturing temperature, dense structure, high purity and low cost. In the present paper, the precision machinability of RB-SiC was studied by microindentation and single-point diamond turning (SPDT) tests. The influence of depth of cut and tool feed rate on surface roughness and cutting force was investigated. Results showed that there was no clear ductile-brittle transition in machining behavior. The material removal mechanism involves falling of the SiC grains and intergranular microfractures of the bonding silicon, which prevents from large-scale cleavage fractures. The minimum surface roughness depends on the initial material microstructure in terms of sizes of the SiC grains and micro pores. This work preliminarily indicates that SPDT can be used as a high-efficiency machining process for RB-SiC.

A Study of Factors Affecting Surface Quality in Ultra-Precision Raster Milling

2007 ◽  
Vol 339 ◽  
pp. 400-406 ◽  
Author(s):  
M.N. Cheng ◽  
Chi Fai Cheung ◽  
Wing Bun Lee ◽  
Sandy To
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Dynamic Characteristics ◽  
Diamond Turning ◽  
Factors Affecting ◽  
Cutting Geometry ◽  
Milled Surface ◽  
Ultra Precision ◽  
Process Factors

Ultra-precision raster milling is an emerging manufacturing technology for the fabrication of high precision and high quality components with a surface roughness of less than 10 nm and a form error of less than 0.2 μm without the need for any subsequent post polishing. Surface quality of a raster milled surface is affected by process factors and material factors, respectively. The process factors involve cutting conditions, cutting strategies, and relative vibration between the tool and the workpiece which are related to the cutting geometry and the dynamic characteristics of the cutting process. The material factors considered are material property and swelling of the work materials. Due to different cutting mechanics, the process factors affecting the surface quality are more complicated, as compared with ultra-precision diamond turning, such as swing distance and step distance. This paper presents an experimental investigation of the distinctive process factors affecting the surface roughness in ultra-precision multi-axis raster milling. Experimental results indicate that the influence due to the process factors can be minimized through a proper selection of operational settings and better control of dynamic characteristics of the machine.

Dry WEDM in Improving HS-WEDMed Surface Quality

2008 ◽  
Vol 392-394 ◽  
pp. 624-628 ◽  
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Shuang Shuang Hao ◽  
Shu Qiang Xie ◽  
Xiao Cun Xu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Material Removal ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Dry Wedm ◽  
Finish Cut ◽  
The Relationship

This paper studies the surface quality of mould steel with high-speed wire electrical discharge machining (WEDM) method, which is conducted in gas to improve the accuracy of finish cut, and compares the surface quality in atmosphere and in emulsion dielectric. Experiment results showed that WEDM in atmosphere offers advantages such as better surface roughness and higher material removal rate. The relationship about winding speed and worktable feed on WEDMed surface quality in semi-finishing cut and finishing cut had been obtained. Morover, a new attemption was successful in applying dry WEDM in multiple cut to improve surface roughness.

Dry WEDM in Improving LS-WEDMed Surface Quality

2008 ◽  
Vol 53-54 ◽  
pp. 387-392 ◽  
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Shu Qiang Xie ◽  
Shuang Shuang Hao ◽  
H. Zhao
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Wire Electrical Discharge Machining ◽  
Dry Wedm ◽  
Cut Surface ◽  
Discharge Gap

Utilizing gas as the dielectric instead of dielectric liquid has enabled the development of dry wire electrical discharge machining (dry WEDM) technology for finishing cut. Experiment results showed that Low-Speed WEDM (LS-WEDM) in gas offers advantages such as better straightness, and shorter discharge gap. This paper studies on influence of different gas dielectrics, wire winding speed and pulse duration on the WEDMed surface quality (discharge gap, straightness, surface roughness, removal rate) in finishing. New attempt of applying dry WEDM as the 4th cut had been proved feasible in improving conventional multiple cut surface quality of LS-WEDM.

Surface quality of large KDP crystal fabricated by single-point diamond turning

2006 ◽  
Author(s):  
Jing Hou ◽  
Jianfeng Zhang ◽  
Jinlin Chen ◽  
Xiaoli Zhang ◽  
Dezhi Hu
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Diamond Turning ◽  
Kdp Crystal
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