The Experts below are selected from a list of 114651 Experts worldwide ranked by ideXlab platform
Dong Yang - One of the best experts on this subject based on the ideXlab platform.
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Surface Topography analysis and cutting parameters optimization for peripheral milling titanium alloy ti 6al 4v
International Journal of Refractory Metals & Hard Materials, 2015Co-Authors: Dong Yang, Zhan Qiang LiuAbstract:Abstract This paper presents the effect of cutting parameters (cutting speed, feed rate and radial depth of cut) on Surface Topography in peripheral milling of titanium alloy Ti–6Al–4V. Peripheral milling experiments based on the Taguchi method have been conducted on Ti–6Al–4V to characterize Surface topographies by various milling conditions. Surface analysis techniques including Surface defects, multiple linear regression analysis of Surface parameters and auto-correlation analysis of the Surface profile, were implemented to characterize the machined Surface Topography. The experimental results have shown that the main forms of Surface defect in peripheral milling of Ti–6Al–4V are feed marks, scratch marks, adhered material particles, etc. The high quality of the machined Surface can be obtained in the combined conditions with high cutting speed, low feed and small radial depth of cut. Auto-correlation analysis is used to describe the spatial relation dependence of the Surface Topography, the direction and periodicity of the Surface texture. Increasing cutting speed is helpful to reduce the random components in the auto-correlation spectra of the machined Surfaces. However, increasing feed rate has the opposite effect. Radial depth of cut has no significant influence on auto-correlation spectra in finish milling.
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Surface plastic deformation and Surface Topography prediction in peripheral milling with variable pitch end mill
International Journal of Machine Tools & Manufacture, 2015Co-Authors: Dong YangAbstract:Abstract Peripheral milling with variable pitch end mills is available to improve the Surface integrity during final machining. Among the indicators of Surface integrity, Surface plastic deformation and Surface Topography are the foremost characteristics. In this paper, two main aspects are included. On the one hand, a unique generic technique in terms of depth of plastic deformation, plastic strains distribution for analyzing the plastic deformations on the work piece is presented. The presented technique applies the problem of the Flamant–Boussinesq in the plastic deformation problem. Through experimental verification, the analytical results have a higher accuracy. On the other hand, the Surface generation mechanism in peripheral milling with variable pitch end mills is studied. Corresponding Surface generation model, which is used to predict the generated Surface Topography with incorporating the cutting process parameters and several sources of machining error such as tilting, run-out, deflection of the tool and work piece displacement, is proposed. Through a set of cutting tests, it is confirmed that the presented model predicts the Surface texture and roughness parameters precisely. By the sensitivity analysis, Helix angle and feed rate have significant influences on Surface Topography, while the effects of cutting speed on Surface Topography can be neglected when the effects of the machining error sources on the behavior and performance of the model are not considered. Among the sources of machining errors, the deflection of the tool has the most significant impact on the Surface profile. The sequence is the displacement of the work piece and the run-out of the tool.
Richard Leach - One of the best experts on this subject based on the ideXlab platform.
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noise evaluation of a point autofocus Surface Topography measuring instrument
Measurement Science and Technology, 2018Co-Authors: Giacomo Maculotti, Xiaobing Feng, Maurizio Galetto, Richard LeachAbstract:In this work, the measurement noise of a point autofocus Surface Topography measuring instrument is evaluated, as the first step towards establishing a route to traceability for this type of instrument. The evaluation is based on the determination of the metrological characteristics for noise as outlined in draft ISO specification standards by using a calibrated optical flat. The static noise and repeatability of the autofocus sensor are evaluated. The influence of environmental disturbances on the measured Surface Topography and the built-in software to compensate for such influences are also investigated. The instrument was found to have a measurement noise of approximately 2 nm or, when expressed with the measurement bandwidth, 0.4 nm/√Hz for a single-point measurement.
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Surface Topography investigations on nickel alloy 625 fabricated via laser powder bed fusion
The International Journal of Advanced Manufacturing Technology, 2018Co-Authors: Tugrul Ozel, Alka Donmez, Ayca Altay, Richard LeachAbstract:Laser powder bed fusion as an additive manufacturing process produces complex Surface Topography at multiple scales through rapid heating, melting, directional cooling, and solidification that are often governed by laser path and layer-to-layer scanning strategies and influenced by process parameters such as power, scan velocity, hatch distance, and resultant energy density. Investigations on manufactured Surfaces, as-built and after applying electropolishing, are performed using stylus profilometry, digital optical microscopy, and scanning electron microscopy techniques to reveal the complex Surface texture of the nickel alloy 625 test cubes that are produced by following an experimental design. Surface texture is further explored using image processing together with machine learning-based algorithms. Measurement uncertainty is also discussed briefly. The results reveal a complex nature of laser powder bed fusion created Surface Topography and textures as exposed with electropolishing that may further lead to a quantitative understanding of such textures and their formations influenced by different scanning strategies and process parameters.
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calibration of the scales of areal Surface Topography measuring instruments part 3 resolution
Measurement Science and Technology, 2013Co-Authors: Claudiu Giusca, Richard LeachAbstract:Calibration of the scales of areal Surface Topography measuring instruments requires testing of the resolution. Several designs of artefact that allow testing of the resolution of such instruments are currently available; however, analysis methods need to be developed to provide comparable results. A novel method for determining the lateral resolution of areal Surface Topography measuring instruments is presented. The method uses a type ASP (star-shaped) material measure. To demonstrate the validity of the method, the resolution of a phase shifting interferometer was determined based on the ISO definition of the lateral period limit. Using the proposed method, the type ASP material measure, which is often used to judge qualitatively an instrument's resolution, can be used to quantitatively estimate the resolution of instruments using the Topography data.
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determination of the transfer function for optical Surface Topography measuring instruments a review
Measurement Science and Technology, 2013Co-Authors: Claudiu Giusca, Matthew R Foreman, Jeremy M Coupland, Peter Torok, Richard LeachAbstract:A significant number of areal Surface Topography measuring instruments, largely based on optical techniques, are commercially available. However,implementation of optical instrumentation into production is currently difficult dueto the lack of understanding of the complex interaction between the light and the component Surface. Studying the optical transfer function of the instrument can help address this issue. Herea review is given of techniques for the measurement of optical transfer functions. Starting from the basis of a spatially coherent, monochromatic confocal scanning imaging system, the theory of optical transfer functions in three-dimensional (3D) imaging is presented. Further generalizations are reviewed allowing the extension of the theory to the description of conventional and interferometric 3D imaging systems. Polychromatic transfer functions and Surface Topography measurements are also discussed. Following presentation of theoretical results, experimental methods to measure the optical transfer function of each class of system are presented, with a focus on suitable methods for the establishment of calibration standards in 3D imaging and Surface Topography measurements.
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calibration of the scales of areal Surface Topography measuring instruments part 1 measurement noise and residual flatness
Measurement Science and Technology, 2012Co-Authors: Richard Leach, Claudiu L Giusca, Franck Helary, Tadas Gutauskas, Lakshmi NimishakaviAbstract:In this paper, we present methods for determining the measurement noise and residual flatness of areal Surface Topography-measuring instruments. The methods are compliant with draft international specification standards on areal Surface texture. We first introduce the international standards framework and then present current methods based on averaging and subtraction to isolate the measurement noise and residual flatness from the sample Surface Topography. These methods are relatively difficult to apply and time consuming in practice. An alternative method is presented based on thresholding and filtering techniques. This method is simple to apply in practice. Traceability and measurement uncertainty are discussed.
Zhan Qiang Liu - One of the best experts on this subject based on the ideXlab platform.
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Surface Topography analysis and cutting parameters optimization for peripheral milling titanium alloy ti 6al 4v
International Journal of Refractory Metals & Hard Materials, 2015Co-Authors: Dong Yang, Zhan Qiang LiuAbstract:Abstract This paper presents the effect of cutting parameters (cutting speed, feed rate and radial depth of cut) on Surface Topography in peripheral milling of titanium alloy Ti–6Al–4V. Peripheral milling experiments based on the Taguchi method have been conducted on Ti–6Al–4V to characterize Surface topographies by various milling conditions. Surface analysis techniques including Surface defects, multiple linear regression analysis of Surface parameters and auto-correlation analysis of the Surface profile, were implemented to characterize the machined Surface Topography. The experimental results have shown that the main forms of Surface defect in peripheral milling of Ti–6Al–4V are feed marks, scratch marks, adhered material particles, etc. The high quality of the machined Surface can be obtained in the combined conditions with high cutting speed, low feed and small radial depth of cut. Auto-correlation analysis is used to describe the spatial relation dependence of the Surface Topography, the direction and periodicity of the Surface texture. Increasing cutting speed is helpful to reduce the random components in the auto-correlation spectra of the machined Surfaces. However, increasing feed rate has the opposite effect. Radial depth of cut has no significant influence on auto-correlation spectra in finish milling.
Xiaoliang Liang - One of the best experts on this subject based on the ideXlab platform.
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Tool wear behaviors and corresponding machined Surface Topography during high-speed machining of Ti-6Al-4V with fine grain tools
Tribology International, 2018Co-Authors: Xiaoliang LiangAbstract:Abstract Rapid tool wear of machining Ti-6Al-4V causes the Surface deterioration and manufacturing cost increasing. This work studied tool wear behaviors and machined Surface Topography during high-speed machining of Ti-6Al-4V. Firstly, detailed wear of tool rake face and flank face were studied in wear Topography and chemical elements. Tool rake face was related to the combined effects of adhesion-diffusion-abrasion wear, while predominant wear mechanism of flank face was adhesion-abrasion. The cutting edge chippings and deformation destroyed the structure and strength of cutting tools. Secondly, the effects of tool wear on the corresponding Surface Topography were evaluated in Surface roughness and defects. The tool flank wear should be controlled in less than 0.2 mm from the viewpoint of getting better Surface Topography.
Alexander S. Arseniev - One of the best experts on this subject based on the ideXlab platform.
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Protein Surface Topography as a tool to enhance the selective activity of a potassium channel blocker.
Journal of Biological Chemistry, 2019Co-Authors: Antonina A. Berkut, Steve Peigneur, Anton O Chugunov, Valentin M Tabakmakher, Konstantin S. Mineev, Nikolay A. Krylov, Peter B. Oparin, Alyona F. Lihonosova, Ekaterina V. Novikova, Alexander S. ArsenievAbstract:: Tk-hefu is an artificial peptide designed based on the α-hairpinin scaffold, which selectively blocks voltage-gated potassium channels Kv1.3. Here we present its spatial structure resolved by NMR spectroscopy and analyze its interaction with channels using computer modeling. We apply protein Surface Topography to suggest mutations and increase Tk-hefu affinity to the Kv1.3 channel isoform. We redesign the functional Surface of Tk-hefu to better match the respective Surface of the channel pore vestibule. The resulting peptide Tk-hefu-2 retains Kv1.3 selectivity and displays ∼15 times greater activity compared with Tk-hefu. We verify the mode of Tk-hefu-2 binding to the channel outer vestibule experimentally by site-directed mutagenesis. We argue that scaffold engineering aided by protein Surface Topography represents a reliable tool for design and optimization of specific ion channel ligands.
