Study on the Surface Roughness and Surface Shape Simulation Based on STEP-NC Turning

2008 ◽  
Author(s):  
Xiusheng Chen ◽  
Chengrui Zhang ◽  
Riliang Liu ◽  
Hongbo Lan
Keyword(s):  
Surface Roughness ◽  
Surface Shape ◽  
Simulation Based

Videooptical Surface Shape and Integrity Estimation in Robots Machining

2013 ◽  
Vol 332 ◽  
pp. 270-275 ◽  
Author(s):  
Tadeusz Mikolajczyk
Keyword(s):  
Surface Roughness ◽  
Industrial Robot ◽  
Surface Shape ◽  
Engineering System ◽  
Machined Surface ◽  
Reflectivity Method ◽  
Machining System ◽  
Grinding Tool ◽  
Smart Machining ◽  
Usb Camera

Paper shows system to surface shape and quality control in machining using industrial robot. To surface control videooptical methods were used. Surface shape was controlled using the special reverse engineering system. To surface roughness measure machined surface reflectivity method was used. Used own constructions non contact system was equipped with red laser light and USB camera. Wrist of robot was equipped with grinding tool. In paper shows some algorithms of presented processes. Shown too examples of experiments results in surface roughness measure in start end of grinding process. First trials of presented system shows possibility to build smart machining system for finishing of surface with unknown shape.

Fractal Dimension and Multifractal Spectra of INGAN/GAN Self-Assembled Quantum Dots Films

2008 ◽  
Author(s):  
K. T. Lam
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Fractal Dimension ◽  
High Speed ◽  
Surface Characterization ◽  
Chemical Vapor ◽  
Surface Shape ◽  
Root Mean Square Roughness ◽  
Multifractal Spectra ◽  
Self Assembled

The surface shape and microstructure of semiconductor thin films, especially nanometer thin films, greatly influence such physical characteristics as the electricity, magnetic and optics nature to the thin films, etc. In this work, we use the fractal dimension and multifractal spectra to study the surface morphology of annealed InGaN/GaN self-assembled quantum dot (SAQD) films. Samples used in this study were grown on (0001)-oriented sapphire (Al2O3) substrates in a vertical low-pressure metalorganic chemical vapor deposition (MOCVD) reactor with a high-speed rotation disk. The fractal dimension and multifractal spectra can be used to describe the influence of different annealing conditions on surface characterization. Fractal analysis reveals that both the average surface roughness and root-mean-square roughness of nanostructure surfaces decreased after thermal annealing. It can be seen that a smoother surface was obtained after an annealing temperature of 800°C, and it implies that the surface roughness of this case is minimum in all tests. The results of this paper also include a mathematical model to describe the observation of fractal and multifractal characteristics in semiconductor nanostructure films.

scholarly journals Influence of Surface State in Micro-Welding of Copper by Nd:YAG Laser

2018 ◽  
Vol 8 (12) ◽  
pp. 2364 ◽  
Author(s):  
Martin Maina ◽  
Yasuhiro Okamoto ◽  
Reiki Inoue ◽  
Shin-ichi Nakashiba ◽  
Akira Okada ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface State ◽  
Nd:Yag Laser ◽  
Absorption Rate ◽  
Processing Condition ◽  
Energy Utilization ◽  
Surface Shape ◽  
Deep Penetration ◽  
Welding Quality ◽  
Enhanced Absorption

Laser welding of copper is characterized by low and unstable light absorption around 1000 nm wavelength. Combination of high thermal conductivity and low melting point makes it difficult to obtain good welding quality and leads to low energy utilization. To improve efficiency and welding quality, a technique to enhance process stability using 1064 nm wavelength Nd:YAG laser has been proposed, and absorption rate and molten volume in laser micro-welding were discussed. Since the surface state of specimen affects absorption phenomena, effects of surface shape and surface roughness were investigated. Absorption rate and molten volume were increased by creating appropriate concave holes and by controlled surface roughness. Stable micro-welding process with deep penetration and good surface quality was achieved for transitional processing condition between heat conduction and keyhole welding, by enhanced absorption rate.

Radial Throw in Micromilling: A Simulation-Based Study to Analyze the Effects on Surface Quality and Uncut Chip Thickness

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Sudhanshu Nahata ◽  
Recep Onler ◽  
O. Burak Ozdoganlar
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Accurate Determination ◽  
Chip Thickness ◽  
Quality Metrics ◽  
Uncut Chip Thickness ◽  
Total Displacement ◽  
Simulation Based ◽  
Thickness Variations ◽  
Sidewall Surface

This paper presents a simulation study toward analyzing the effect of radial throw in micromilling on quality metrics and on the deviation in tool-tip trajectory from its prescribed pattern. Both the surface location error (SLE) and the sidewall (peripheral) surface roughness are analyzed. The deviation in tool-tip trajectory is evaluated considering the flute-to-flute variations in the uncut chip thickness and changes in the tooth spacing angle. Radial throw indicates the instantaneous radial location of the tool axis, thereby capturing all salient features of tool-tip trajectory deviations, such as the general elliptical form of the radial motions. This is in contrast to the concept of run-out, which is a scalar quantity (total indicator reading) indicating the total displacement or change in the radial throw measured from a perfect cylindrical surface for one complete rotation of the axis. As such, measurement and analysis of radial throw is essential to understanding micromachining processes. In our previous work, we described an experimental approach for accurate determination of radial throw when using ultra-high-speed micromachining spindles. In this work, we present a simulation-based study to relate radial throw parameters and form to SLE, sidewall surface roughness, flute-to-flute variations of uncut chip thickness, and changes in tooth spacing angle for a two fluted micro-endmill. As expected, our study concludes that the magnitude, orientation, and form of radial throw all significantly affect the studied quality metrics, tooth spacing angle, and the flute-to-flute chip thickness variations. Specifically, the presence of radial throw with an elliptical form induces up to 50% variation in SLE, up to 20% variation in sidewall surface roughness, up to 60% variation in tooth spacing angle deviations, and up to 50% variation in flute-to-flute chip thickness. As such, the presented simulation approach can be used to assess the direct (kinematic) effects of the radial throw parameters on the quality metrics and chip thickness variations.

Evolution of Surface Roughness of a Strained Epitaxial Film Due to Interface Misfit Dislocations

1993 ◽  
Vol 317 ◽  
Author(s):  
F. Jonsdottir ◽  
L. B. Freund
Keyword(s):  
Surface Roughness ◽  
Surface Diffusion ◽  
Chemical Potential ◽  
Epitaxial Film ◽  
Potential Gradient ◽  
Surface Shape ◽  
Misfit Dislocations ◽  
Chemical Potential Gradient ◽  
Strained Layer

ABSTRACTThe appearance of misfit dislocations at the interface between a strained layer and its substrate induces a nonuniform chemical potential along the surface of the layer. Under the assumption that the resulting chemical potential gradient will drive coherent mass rearrangement by surface diffusion, a model of evolution of surface shape is considered which leads to estimates of the surface roughness induced by this mechanism.

Research on Mid-Large-Aperture Aspherical Optical Components Rapid Powerful NC Polishing Technology

2014 ◽  
Vol 487 ◽  
pp. 413-416
Author(s):  
Feng Ming Nie ◽  
Zhan Guo Li ◽  
Qing Tang Wu ◽  
Shan Li ◽  
Huan Wu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Optical Glass ◽  
Surface Shape ◽  
Mode Structure ◽  
Processing Efficiency ◽  
Shape Accuracy ◽  
Optical Components ◽  
Large Aperture ◽  
Polishing Path ◽  
Five Axis

This paper introduces a new devices and technology of large-aperture quadratic optical components rapid powerful NC polishing, it has greatly improved the efficiency and precision of aspheric polishing. Through self-designed five-axis CNC polishing machine, to achieve the controlling of rotation, revolution integral rapid powerful polishing head. By optimizing the process parameters, determine a reasonable polishing path and polishing mode structure, to obtain good experimental results. Size 340mm × 340mm aspheric optical glass, surface shape accuracy PV λ / 5, surface roughness Rq 1.2nm, processing efficiency has been effectively improved, surface shape convergence stable.

Velopharyngeal mucosal surface topography in healthy subjects and subjects with obstructive sleep apnea

2017 ◽  
Vol 122 (3) ◽  
pp. 482-491 ◽  
Author(s):  
Christopher Lambeth ◽  
Jason Amatoury ◽  
Ziyu Wang ◽  
Sheryl Foster ◽  
Terence Amis ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Surface Topography ◽  
Upper Airway ◽  
Magnetic Resonance Images ◽  
Mucosal Surface ◽  
Surface Shape ◽  
Obstructive Sleep ◽  
Surface Models

Macroscopic pharyngeal anatomical abnormalities are thought to contribute to the pathogenesis of upper airway (UA) obstruction in obstructive sleep apnea (OSA). Microscopic changes in the UA mucosal lining of OSA subjects are reported; however, the impact of these changes on UA mucosal surface topography is unknown. This study aimed to 1) develop methodology to measure UA mucosal surface topography, and 2) compare findings from healthy and OSA subjects. Ten healthy and eleven OSA subjects were studied. Awake, gated (end expiration), head and neck position controlled magnetic resonance images (MRIs) of the velopharynx (VP) were obtained. VP mucosal surfaces were segmented from axial images, and three-dimensional VP mucosal surface models were constructed. Curvature analysis of the models was used to study the VP mucosal surface topography. Principal, mean, and Gaussian curvatures were used to define surface shape composition and surface roughness of the VP mucosal surface models. Significant differences were found in the surface shape composition, with more saddle/spherical and less flat/cylindrical shapes in OSA than healthy VP mucosal surface models ( P < 0.01). OSA VP mucosal surface models were also found to have more mucosal surface roughness ( P < 0.0001) than healthy VP mucosal surface models. Our novel methodology was utilized to model the VP mucosal surface of OSA and healthy subjects. OSA subjects were found to have different VP mucosal surface topography, composed of increased irregular shapes and increased roughness. We speculate increased irregularity in VP mucosal surface may increase pharyngeal collapsibility as a consequence of friction-related pressure loss. NEW & NOTEWORTHY A new methodology was used to model the upper airway mucosal surface topography from magnetic resonance images of patients with obstructive sleep apnea and healthy adults. Curvature analysis was used to analyze the topography of the models, and a new metric was derived to describe the mucosal surface roughness. Increased roughness was found in the obstructive sleep apnea vs. healthy group, but further research is required to determine the functional effects of the measured difference on upper airway airflow mechanics.

Effects analysis of processing factors on surface quality in optical grinding using ɛ-support vector regression

2015 ◽  
Vol 229 (18) ◽  
pp. 3449-3458 ◽  
Author(s):  
Dongxu Zhang ◽  
Ping Yang ◽  
Yanting Zhang ◽  
Guo Bi ◽  
Yinbiao Guo
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Support Vector Regression ◽  
Surface Quality ◽  
Processing Condition ◽  
Surface Shape ◽  
Support Vector ◽  
Technological Parameters ◽  
Effect Factor ◽  
Processing Factors

The aim of this study was to quantitatively analyze the effects of the processing factors on the surface quality in precision optical grinding. A novel identifying model which incorporates an effect factor is proposed based on ɛ-support vector regression ( ɛ-SVR). Experiments were designed and performed to investigate the effects of the processing factors comprising the technological parameters and processing condition factors on the surface quality, and the experimental data were used to train the ɛ-SVR. Subsequently, the values of effect factor were solved to quantify the effects of the respective processing factors on the surface quality. Further experiments were performed to verify the effectiveness of effect factor. ɛ-SVRs of which the input vectors were multiplied and not multiplied by effect factor were respectively used to predict the surface quality including the surface roughness and surface shape peak–valley value. The values calculated by ɛ-SVR using effect factor were found to be much more accurate than those calculated without using effect factor. The results confirmed the effectiveness of identifying model for precision optical grinding.

Multifractal Spectra of INGaN/GaN Self-Assembled Quantum Dots Films

2010 ◽  
Vol 1 (3) ◽  
Author(s):  
Artde D. K. T. Lam
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
High Speed ◽  
Surface Characterization ◽  
Chemical Vapor ◽  
Surface Shape ◽  
Root Mean Square Roughness ◽  
Organic Chemical ◽  
Multifractal Spectra ◽  
Self Assembled

The surface shape and microstructure of semiconductor thin films, especially nanometer thin films, have important influence to construct physical characteristics, such as electricity, magnetic, and optics nature to the thin films. In this work, we use the multifractal spectra to study the surface morphology of InGaN/GaN self-assembled quantum dot films after the annealed process. Samples used in this study were grown on the (0001)-oriented sapphire (Al2O3) substrates in a vertical low-pressure metal-organic chemical vapor deposition reactor with a high-speed rotation disk. The fractal dimension and multifractal spectra can be used to describe the influence of different annealed conditions on surface characterization. Fractal analysis reveals that both the average surface roughness and root-mean-square roughness of nanostructure surfaces are decreased after the thermal annealing process. It can be seen that a smoother surface was obtained under an annealing temperature at 800°C, and it implies that the surface roughness of this case is minimum in all tests. The results of this paper also described a mathematical modeling method for the observation of the fractal and multifractal characteristics in a semiconductor nanostructure films.

Surface Morphology Simulation of High Speed Milled of Face Milling Cutters

2011 ◽  
Vol 305 ◽  
pp. 225-229
Author(s):  
Ai Qin Lin ◽  
Min Li Zheng ◽  
Chun Guang Fan ◽  
Lin Yang
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Simulation Modeling ◽  
High Speed ◽  
Cutting Parameters ◽  
Geometric Shape ◽  
Surface Shape ◽  
Geometrical Parameters ◽  
High Speed Cutting ◽  
Tooth Surfaces

To surface milling cutters for research object, established considering the single spindle partial pendulum milling cutter tooth surfaces of high speed cutting 3d surface morphology simulation model by using graphic matrix transformation principle and vector algorithms. Comparing the simulation and forecast of surface morphology and surface roughness with the actual machining surface morphology and surface roughness by using the workpiece simulation algorithm meshing, we verify the correctness of the simulation model. The simulation analyses the influence regularity of surface morphology and surface roughness by changing cutting parameters and geometrical parameters. This can help us choosing the reasonable cutting parameters and geometrical parameters and have significance on the actual machining. The surface milling cutters are high efficiency and good quality of cutting big plane or curved surface. With the development of high speed cutting technology, in high speed milling process, product crumbs tumor and scales thorn hardly exists, so cutter geometrical parameters, cutting data and so on will be the main influence reasons of surface roughness. In order to satisfied the quality requirements, at present, we choice tools and determine the milling parameters depending on experience but it is limited. The surface roughness of the processing components is reflected intuitively by processed surface of microscopic geometric shape. So surface of microscopic geometric shape produced by theory emulation is significant to forecast the surface roughness and selecting reasonable cutting parameters. Currently, there are some simulation method researches about surface of microscopic geometric shape. Zhao Xiao ming et al [1, 2] has researched the simulation modeling of microscopic geometric shape of ball end mills during processing; Xu An ping et al [3, 4] has researched the simulation modeling methods of peripherally milling processing; Zhang Guang Peng et al [5] has researched the inversion multiple tooth surfaces of the milling cutter surface morphology simulation and develop simulation software. But all above researches are ideal simulation of surface shape. There are few researches about simulation of surface shape on condition of spindle partial pendulum. Based on object of surface milling cutters, this article researches simulation modeling methods of surface topography on condition of high speed milling and give an account of the corresponding simulation algorithm. From the article, we also get the influence law of microscopic geometric shape depending on different milling dosage, cutter geometrical parameters and eccentric quantity and get the significance conclusion to actual production.

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