Turning parameter optimization for diffraction effect suppression of diamond-turned surface combining surface micro-topography model and scattering theory

2021 ◽  
pp. 1-22
Author(s):  
Pengfeng Sheng ◽  
Zhengxiang Shen ◽  
Li Jiang ◽  
Shenghuan Fang ◽  
Zhanshan Wang
Keyword(s):  
Surface Finish ◽  
Scattering Theory ◽  
Diamond Turning ◽  
Diffraction Effect ◽  
Optical Surface ◽  
Diffraction Intensity ◽  
Tool Marks ◽  
Topography Model ◽  
The Relationship ◽  
Micro Topography

Abstract The diamond-turning process is a mean optical surface generation technique with high figure accuracy and surface finish. The diamond-turned surface has a significant diffraction effect introduced by the tool marks remaining on the surface, which heavily degrade the optical performance in the visible wavelength spectrum. The traditional approach that was used to eliminate this effect was polishing. In this paper, we present a method to find turning parameters that can generate an optical surface without diffraction effect directly by coupling a surface micro-topography model of a turned surface via the scattering theory The surface micro-topography model of the turned surface reveals the relationship between tool marks and the diamond-turning parameters (DTPs). The scattering theory reveals the relationship between diffraction intensity distributions (DIDs) and surface micro-topography of the turned surface. Therefore, we obtained the relationship between DIDs and DTPs. The diffraction effect is considered to be eliminated when the first-order diffraction intensity is less than 0.01% of incidence intensity. The criterion of turning parameters for diffraction elimination is then obtained. Finally, turning experiments are performed to confirm the effectiveness of this method, and the diffraction-free surface finish is achieved.

Form Accuracy of Optical Mould Inserts Made from Rapidly Solidified Aluminium Alloys

2015 ◽  
Vol 828-829 ◽  
pp. 62-68
Author(s):  
Khaled Abou-El-Hossein
Keyword(s):  
High Precision ◽  
Surface Finish ◽  
Single Point ◽  
Cutting Parameters ◽  
Diamond Turning ◽  
Machining Parameters ◽  
Optical Surface ◽  
Form Accuracy ◽  
Optical Surfaces ◽  
Rapidly Solidified

Plastic optical components and lenses produced in mass quantities are usually manufactured using high-precision plastic injection technology. For that, high-precision plastic moulds with aluminium optical inserts made with extremely high dimension accuracy and high optical surface quality are used. Ultra-high precision single-point diamond turning have been successfully used in shaping optical mould inserts from various aluminium grades such as traditional 6061. However, extreme care should be taking when selecting machining parameters in order to produce optically valid surfaces before premature tool wear takes place especially when the machined optical materials has inadequate machining database. The current experimental study looks at the effect of cutting conditions on optical surfaces made from aluminium. The study embarks on helping establish some diamond machining database that helps engineers select the most favourable cutting parameters. The papers reports on the accuracy and surface finish quality received on an optical surface made on mould inserts from a newly developed aluminium alloy. Rapidly solidified aluminium (RSA) grades have been developed recently to address the various problems encountered when being cut by single-point diamond turning operation. The material is characterised by its extremely fine grained microstructure which helps extend the tool life and produce optical surfaces with nanometric surface finish. It is found the RSA grades can be successfully used to replace traditional optical aluminium grades when making optical surfaces. Surface finishes of as low as 10 nanometres and form accuracy of less than one micron can be achieved on RSA.

One-Dimensional Diffraction Grating of Poly(Methacrylic Acid) Brushes For The Rapid Label-Free Detection of Yersinia Pestis With a Reflective Laser System

2021 ◽  
Author(s):  
Feng-Ping Lin ◽  
Hui-Ling Hsu ◽  
Hui-Chung Lin ◽  
Hsin-Hsien Huang ◽  
Chien-Hsing Lu ◽  
...  
Keyword(s):  
Laser Beam ◽  
Yersinia Pestis ◽  
Methacrylic Acid ◽  
Limit Of Detection ◽  
Incident Angle ◽  
Diffraction Effect ◽  
Label Free ◽  
Diffraction Intensity ◽  
One Dimensional ◽  
Label Free Detection

Abstract Background: Because of the low sensitivity of commercial products, development of a facile method to rapidly identify plague on-site remains highly attractive. Line arrays of poly(methacrylic acid) (PMAA) brushes were grafted using a photoresist template to fabricate one-dimensional diffraction gratings (DGs). The as-prepared samples first bound protein G to immobilize and orient the tails of the antibody of Yersinia pestis (abY). A laser beam was employed to analyze the 2D and 3D reflective signals of DGs at an incident angle of 45°. The abY-tailed PMAA DG possessed an optical feature with a characteristic diffraction effect along the SII, in which the projection of the laser beam on the plane of the DG chip was parallel to the strips, and ST configurations, in which they were perpendicular. A fluidic diffraction chip based on the abY-tailed PMMA DG was fabricated to examine the ability to detect Yersinia pestis along the ST configuration. Results: Upon flowing through the chip, Yersinia pestis was attached to the abY-tailed PMMA DG, which changed the diffraction intensity. The degree of the diffraction intensity exhibited a linear response to Yersinia pestis at concentrations from 102 to 107 CFU mL−1, and the limit of detection was 75 CFU mL−1, 1000 times lower than a commercial product (Alexter Bio-Detect Test). The diffractive sensor could selectively detect Yersinia pestis in spiked serum samples, with excellent standard deviation and recovery. Conclusion: Our platform provides a simple, label-free method for on-site plague diagnosis to prevent the highly rapid transmission of plague.

Study of the Relationship between Tool Wear and Surface Finish in Turning with Carbide Tool

2014 ◽  
Vol 902 ◽  
pp. 95-100 ◽  
Author(s):  
Heraldo J. Amorim ◽  
Augusto O. Kunrath Neto
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Surface Finish ◽  
Cutting Speed ◽  
Single Equation ◽  
Carbon Steels ◽  
High Dispersion ◽  
Exponential Relationship ◽  
Processed Material ◽  
The Relationship

The aim of this work is to analyze the tool wear effects on surface finish of machined components. Long-term machinability tests were performed for ASTM 1040 and 1045 carbon steels with carbide tools, in which tool wear and surface roughness were periodically evaluated. Surface finish was analyzed as a function of processed material and cutting speed with new machining tool, and a significant influence was found for cutting speed at a confidence interval of 10%. When evaluated as a function of time and tool wear, surface roughness showed an exponential relationship with both variables. However, a high dispersion occurs close to the end of tool life, especially for AISI 1040 steel. Weak influence of cutting speed (for the range of speeds tested) was observed on the relationship between tool wear and surface finish, indicating that a single equation can describe its behavior for all studied conditions. The relationship between the surface roughness and the cutting time was found to be stronger for the ABNT 1040 steel.

Fundamentals of Kinematical X-Ray Scattering Theory

2014 ◽  
pp. 1-14
Keyword(s):  
Scattering Theory ◽  
Profile Analysis ◽  
Reciprocal Lattice ◽  
Line Profile Analysis ◽  
X Ray ◽  
X Ray Scattering ◽  
Basic Concepts ◽  
Lattice Planes ◽  
The Relationship ◽  
Ray Scattering

The broadening of X-ray line profiles is usually described by the kinematical scattering theory. In this chapter, the basic concepts and equations of the kinematical X-ray scattering are presented in order to better understand the theory of line profile analysis. The correlation between the crystal structure and the diffracted intensity distribution is shown. The scattering angles of the diffracted peak maxima are given by the Ewald construction in the reciprocal space. The correspondence between the reciprocal lattice vectors and the lattice planes is also presented, and the relationship between the scattering angle and the lattice plane spacing is given by Bragg’s law.

The Effect of Surface Finish on Zinc Whisker Growth

2012 ◽  
Vol 472-475 ◽  
pp. 2756-2759
Author(s):  
Wen Cui ◽  
Shao Jun Qi
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Finish ◽  
Whisker Growth ◽  
Experimental Conditions ◽  
Steel Substrates ◽  
The Relationship ◽  
Rough Surface Finish ◽  
Scanning Electron ◽  
Effect Of Surface

To understand the relationship between surface finish and zinc whisker growth, this study investigated the growth of whiskers on two mild steel substrates of different surface finish by Field Emission Gun Scanning Electron Microscope (FEG SEM). Results show that, under the same experimental conditions, deposits on substrates with a mirror finish grew less whiskers and nodules than substrates with a rough surface finish.

Planar nanogrinding of a fine grained WC-Co composite for an optical surface finish

2005 ◽  
Vol 26 (7-8) ◽  
pp. 766-773 ◽  
Author(s):  
Ling Yin ◽  
J.P. Pickering ◽  
K. Ramesh ◽  
H. Huang ◽  
A.C. Spowage ◽  
...  
Keyword(s):  
Surface Finish ◽  
Optical Surface ◽  
Fine Grained
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