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.

Effects of the Tool Angles on the Machined Surface Quality of KDP Crystal in Diamond Turning

2007 ◽  
Vol 364-366 ◽  
pp. 297-301 ◽  
Author(s):  
Jing He Wang ◽  
Ming Jun Chen ◽  
Shen Dong ◽  
Shi Qian Wang
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Rake Angle ◽  
Diamond Turning ◽  
Precision Machining ◽  
Machined Surface ◽  
Kdp Crystal ◽  
Factors Affecting ◽  
Ultra Precision ◽  
Back Angle

In the ultra-precision machining of KDP crystal, there are many factors affecting the surface quality[1-3]. The experiments show that the rake angle and back angle of the tool have significant effects on machined surface roughness. Therefore, an efficient way to improve the surface roughness is to select a proper negative rake angle. In this study, the ANSYS static analysis method was employed to analyze the stress field distribution within the whole cutting region. A finite element simulation model was set up to calculate the residual stresses variation with tool’s angles, which can be considered to select optimal rake and back angles in the ultra-precision machining of KDP crystal. Results show that the optimal tool rake angle and back angle are -49° and 7°, respectively. Finally, by using different tool angles to process KDP crystal and utilizing AFM to analyze the surface roughness, it can be found that the measurement results agree well with what are deduced from theoretical calculation.

EVALUATION OF A REGRESSION PREDICTION MODEL FOR SURFACE ROUGHNESS OF WOOD–POLYETHYLENE COMPOSITE (WPC)

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850033
Author(s):  
WENYONG SHI ◽  
YAN MA ◽  
CHUNMEI YANG ◽  
BIN JIANG ◽  
ZHE LI
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Prediction Model ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Wood Powder ◽  
Polyethylene Composite ◽  
Milled Surface ◽  
Powder Content

Milling processing is an important way to obtain wood–polyethylene composite (WPC) end products. In order to improve the processing efficiency and surface quality of WPC and meet the practical application requirements, this paper focussed on morphology and roughness of the WPC-milled surface and studied surface quality changes under different cutting parameters and milling methods through multi-parameters milling experiments. The milling surface morphology and roughness of WPC were analyzed and measured during cut-in, cutting and cut-out sections. It also revealed the affect rule of different cutting parameters and milling methods on milled surface morphology and roughness. The results show that the milling surface roughness of WPC products with wood powder content of 70% is significantly larger than the one whose wood powder content is 60%, and defects such as holes are also relatively more. Finally, a surface roughness prediction model was established based on the mathematical regression method and its multi-factor simulation was carried out. A comparative analysis of predictive and experimental values was performed to verify the reliability of the model. It could also provide theoretical guidance and technical guarantee for high processing quality of WPC milling and cutting.

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。

scholarly journals Effect of cutting conditions on quality of milled surface of medium-density fibreboards

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 746-766
Author(s):  
Richard Kminiak ◽  
Mikuláš Siklienka ◽  
Rastislav Igaz ◽  
Ľuboš Krišťák ◽  
Tomáš Gergeľ ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Feed Rate ◽  
Medium Density ◽  
Milling Cutter ◽  
Operation Speed ◽  
Constant Operation ◽  
Milled Surface ◽  
Cutting Direction

The quality of milled surface medium-density fibreboards (MDF) and the effect of the wrong milling direction during the process of automatic milling in real conditions in practice (production machine, production tool, and material) are presented in the paper. Moreover, the effect of the double vs. single bladed milling cutter on the final surface quality with the simultaneous changes in individual parameters of feed rate, thickness of the removed layer, and cutting direction was investigated. The MDF was separated using the strategy “one per pass“ with required cutting direction (climb or conventional) and the required thick strips cutting off (4 mm to 16+ mm) at a constant operation speed of the milling cutter (n = 20000 min−1) and a changing feed rate from vf = 1 m/min−1 to vf = 5 m/min−1. The use of a multi-bladed milling cutter resulted in the higher quality of the milled surface in all cases (change in feed rate, thickness of removed layer, and cutting direction). The effect of the wrong milling direction during automatic milling was observed only for a single-bladed milling cutter used. An increase in surface roughness (Ra) occurred; therefore, using the double-bladed milling cutter, which was not associated with an increase in surface roughness, is recommended.

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).

Effect of Honing Parameters on Generated Surface Quality of Cylinder Liner within Automotive Engine Production

2017 ◽  
Vol 261 ◽  
pp. 189-194 ◽  
Author(s):  
Marek Vrabel' ◽  
Ildikó Maňková ◽  
Numan M. Durakbasa
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Experimental Testing ◽  
Cutting Speed ◽  
Cylinder Liner ◽  
Cutting Parameters ◽  
Automotive Engine ◽  
Machining Allowance ◽  
Process Factors

One of the key parameter in evaluation of cylindrical surface quality of the engine liners is surface roughness. A large number of process factors affecting a final surface topography, which has direct impact on fuel consumption and CO2 emission. A suitable choice of honing conditions can results not only to better surface quality, but it can contributes to reducing of environmental impacts in automobile transport. Twelve different engine cylinder liners were machined in various combinations of cutting parameters. Experimental testing was realised on real production machine tool, where process factors were cutting speed, machining allowance and stone pressure of honing tool. All factors have 4 levels and parameters of surface roughness CR, CF, CL were selected as a variables and suitable indicators for surface quality assessment. The results show that influence of the tool stone pressure on honed surface is more significant than effect of cutting speed. Effect of machining allowance is negligible as well.

Modeling for Prediction of Surface Roughness and Experimental Research in Ultra-Precision Flycutting Machining

2018 ◽  
Author(s):  
Jiasheng Li ◽  
Yang Jiao ◽  
Pinkuan Liu
Keyword(s):  
Surface Roughness ◽  
Prediction Model ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Machining Parameters ◽  
Ultra Precision ◽  
Set Up ◽  
Validation Tests ◽  
The Relationship

To improve the surface quality of the copper and reduce the diamond tool wear, a prediction model is established experimentally for the relationship between surface roughness and machining parameters. Based on the processing principle of flycutting machining, the prediction model for surface roughness is set up by response surface methodology. Then, a machining experiment for the copper is conducted under different cutting parameters designed by Taguchi method and the surface roughness is tested by 4D technology dynamic laser interferometer. After that, the prediction model is obtained by analyzing the experimental data, and the accuracy of the model is verified by analysis of variance (ANOVA), R2 value and residual analysis. Furthermore, the effect of cutting parameters upon the surface roughness is analyzed. Finally, validation tests are conducted to verify the model. Experimental results demonstrate that the prediction model is adequate at 95% confidence level. The output of prediction model helps to select cutting parameters to reduce surface roughness which ensures surface quality in ultra-precision fly cutting machining.

Observation in the Surface Roughness of Silicon Wafer during Semi-Fixed Abrasive Machining with Large Grains

2009 ◽  
Vol 69-70 ◽  
pp. 253-257
Author(s):  
Ping Zhao ◽  
Jia Jie Chen ◽  
Fan Yang ◽  
K.F. Tang ◽  
Ju Long Yuan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Silicon Wafer ◽  
Processing Parameters ◽  
Wafer Surface ◽  
Abrasive Machining ◽  
Fixed Abrasive ◽  
Is Failure ◽  
Better Than

Semi-fixed abrasive is a novel abrasive. It has a ‘trap’ effect on the hard large grains that can prevent defect effectively on the surface of the workpiece which is caused by large grains. In this paper, some relevant experiments towards silicon wafers are carried out under the different processing parameters on the semi-fixed abrasive plates, and 180# SiC is used as large grains. The processed workpieces’ surface roughness Rv are measured. The experimental results show that the surface quality of wafer will be worse because of higher load and faster rotating velocity. And it can make a conclusion that the higher proportion of bond of the plate, the weaker of the ‘trap’ effect it has. Furthermore the wet environment is better than dry for the wafer surface in machining. The practice shows that the ‘trap’ effect is failure when the workpiece is machined by abrasive plate which is 4.5wt% proportion of bond in dry lapping.

The mechanism of process parameters influencing the AlSi10Mg side surface quality fabricated via laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shimin Dai ◽  
Hailong Liao ◽  
Haihong Zhu ◽  
Xiaoyan Zeng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Laser Power ◽  
Side Surface ◽  
Laser Powder Bed Fusion ◽  
Scanning Velocity ◽  
Content Type ◽  
Powder Bed

Purpose For the laser powder bed fusion (L-PBF) technology, the side surface quality is essentially important for industrial applicated parts, such as the inner flow parts. Contour is generally adopted at the parts’ outline to enhance the side surface quality. However, the side surface roughness (Ra) is still larger than 10 microns even with contour in previous studies. The purpose of this paper is to study the influence of contour process parameters, laser power and scanning velocity on the side surface quality of the AlSi10Mg sample. Design/methodology/approach Using L-PBF technology to manufacture AlSi10Mg samples under different contour process parameters, use a laser confocal microscope to capture the surface information of the samples, and obtain the surface roughness Ra and the maximum surface height Rz of each sample after analysis and processing. Findings The results show that the side surface roughness decreases with the increase of the laser power at the fixed scanning velocity of 1,000 mm/s, the side surface roughness Ra stays within the error range as the contour velocity increases. It is found that the Ra increases with the scanning velocity increasing and the greater the laser power with the greater Ra increases when the laser power of contour process parameters is 300 W, 350 W and 400 W. The Rz maintain growth with the contour scanning velocity increasing at constant laser power. The continuous uniform contour covers the pores in the molten pool of the sample edge and thus increase the density of the sample. Two mechanisms named “Active adhesion” and “Passive adhesion” cause sticky powder. Originality/value Formation of a uniform and even contour track is key to obtain the good side surface quality. The side surface quality is determined by the uniformity and stability of the contour track when the layer thickness is fixed. These research results can provide helpful guidance to improve the surface quality of L-PBF manufactured parts.

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