scholarly journals Design and Fabrication of Laser Protective Lenses Based on Multilayered Notch Filter with Low Residual Stress and Low Surface Roughness

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1513
Author(s):  
Chuen-Lin Tien ◽  
Hong-Yi Lin ◽  
Kuan-Sheng Cheng ◽  
Chih-Kai Chang
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Filter Design ◽  
Notch Filter ◽  
Transmission Band ◽  
Optical Transmittance ◽  
Electron Beam Evaporation ◽  
Center Wavelength ◽  
Stress Surface ◽  
Probe Microscope

We present a new laser protective lens based on a multilayered notch filter design with low residual stress and low surface roughness. An18-layer notch filter was prepared by electron beam evaporation with an ion-assisted deposition technique, which was composed of SiO2 and Nb2O5 with a center wavelength of 532 nm. The optical transmittance, residual stress, surface roughness, and surface morphology were measured by a UV/VIS/NIR spectrophotometer, Twyman–Green interferometer, scanning probe microscope, Linnik microscopic interferometer, and field-emission scanning electron microscopy (FE-SEM). The transmittance of the notch filters at center wavelength is 0.2%, and the average transmittance of the transmission band is about 70%. The residual stress of the notch filter is −0.298 GPa, and the root mean square surface roughness is 1.88 nm. The experimental results show that the optical transmittance meets the design requirements.

scholarly journals Design and Fabrication of a Cost-Effective Optical Notch Filter for Improving Visual Quality

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Chuen-Lin Tien ◽  
Hong-Yi Lin ◽  
Kuan-Sheng Cheng ◽  
Chun-Yu Chiang ◽  
Ching-Ying Cheng
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Notch Filter ◽  
Transmission Band ◽  
Visual Quality ◽  
Cost Effective ◽  
Optical Transmittance ◽  
Electron Beam Evaporation ◽  
Central Wavelength ◽  
Multilayer Design

This study presents a multilayer design and fabrication of an optical notch filter for enhancing visual quality. A cost-effective multilayer design of notch filter with low surface roughness and low residual stress is proposed. A 9-layer notch filter composed of SiO2 and Nb2O5 with a central wavelength of 480 nm is prepared by electron beam evaporation combined with ion-assisted deposition. The optical transmittance, residual stress, and surface morphology are measured by a UV/VIS/NIR spectrophotometer, Twyman-Green interferometer and field emission scanning electron microscopy (FE-SEM). The transmittance of the notch filter at the central wavelength is above 15%, and the average transmittance of the transmission band is about 80%. The residual stress of the notch filter is −0.235 GPa, and the root mean square surface roughness is 1.85 nm. For improving the visual quality, a good image contrast can be obtained by observing the microscopic image using the proposed notch filter.

scholarly journals Effect of Lubrication and Forging Load on Surface Roughness, Residual Stress, and Deformation of Cold Forging Tools

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 783
Author(s):  
Karunathilaka ◽  
Tada ◽  
Uemori ◽  
Hanamitsu ◽  
Fujii ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
High Speed ◽  
Compressive Force ◽  
Cold Forging ◽  
Metallic Contact ◽  
Heat Treated ◽  
Stress Surface ◽  
Stress And Deformation ◽  
Forging Load

Cold forging is a metal forming that which uses localized compressive force at room temperature. During the cold forging process, the tool is subjected to extremely high loads and abrasive wear. Lubrication plays an important role in cold forging to improve product quality and tool life by preventing direct metallic contact. Surface roughness and residual stress also greatly affects the service life of a tool. In this study, variations in surface roughness, residual stress, and specimen deformation with the number of cold forging cycles were investigated under different forging conditions. Specimens that were made of heat-treated SKH51 (59–61 HRC), a high-speed tool steel with a polished working surface, were used. The specimens were subjected to an upsetting process. Compressive residual stress, surface roughness, and specimen deformation showed a positive relationship with the number of forging cycles up to a certain limit and became almost constant in most of the forging conditions. A larger change in residual stress and surface roughness was observed at the center of the specimens in all the forging conditions. The effect of the magnitude of the forging load on the above discussed parameters is large when compared to the effect of the lubrication conditions.

Effects of different shot peening parameters on residual stress, surface roughness and cell size

2020 ◽  
Vol 398 ◽  
pp. 126054 ◽  
Author(s):  
Qinjie Lin ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Difa Chen ◽  
Shuangshuang Zhou
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Cell Size ◽  
Shot Peening ◽  
Stress Surface

Parametric Study of Machining Effect on Residual Stress and Surface Roughness of Nickel Base Super Alloy UDIMET 720

2008 ◽  
Vol 47-50 ◽  
pp. 13-16 ◽  
Author(s):  
S.V. Joshi ◽  
S. Paul Vizhian ◽  
B.R. Sridhar ◽  
K. Jayaram
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Turbine Engine ◽  
Milling Parameters ◽  
Stress Surface ◽  
Nickel Base ◽  
Engine Components ◽  
Super Alloy

Machining parameters such as speed (v), feed (f) and depth of cut (d) play an important role in determining the residual stress as well as the surface roughness of a material. The material used for the present study is a nickel based super alloy Udiment 720 which finds applications in the manufacture of gas turbine engine components. Residual stress and surface roughness measured on this material showed different magnitudes for different combinations of milling parameters but did not reveal any definite trend. Analytical relationships developed between the magnitudes of residual stress, surface roughness and milling parameters indicated that combined effects of the milling parameters influence both residual stress and surface roughness.

Materials Factors Influencing the Initiation of Near-Neutral pH SCC on Underground Pipelines

2000 ◽  
Author(s):  
John A. Beavers ◽  
Joshua T. Johnson ◽  
Robert L. Sutherby
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Chemical Composition ◽  
Cyclic Stress ◽  
Strain Behavior ◽  
Inclusion Properties ◽  
Neutral Ph ◽  
Underground Pipelines ◽  
Factors Influencing ◽  
Stress Surface

This paper summarizes the results of research, funded by the Canadian Energy Pipeline Association (CEPA), to determine whether the initiation of near-neutral pH stress corrosion cracking (SCC) could be correlated with pipe metallurgical factors. The factors considered included residual stress, surface roughness, chemical composition, cyclic stress-strain behavior, inclusion properties (number, area, and composition), microhardness, and local galvanic behavior. The project focused on pipes installed from the 1950s through 1970s that exhibit near-neutral-pH SCC. Fourteen pipe samples were examined, ranging in diameter from 8 to 42 inches and grades from X52 to X70.

The Study on Surface Morphology and Residual Stress of Al2O3 Film

2013 ◽  
Vol 275-277 ◽  
pp. 2006-2009
Author(s):  
Ying Dong Pu ◽  
Wu Tang ◽  
Yu Tong Yang
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Film Surface ◽  
Electron Beam Evaporation ◽  
Important Condition ◽  
Force Microscopy ◽  
Atom Force Microscopy ◽  
Film Microstructure

The aluminum oxide (Al2O3) films are grown on n-type Si-(100) substrate by electron beam evaporation at substrate temperature 500°C~800°C. The Al2O3film surface morphology is characterized by atom force microscopy (AFM) to evaluate the grain microstructure, and the residual stress was investigated by wafer stress analyzer. The results show that different substrate temperature is important condition to the properties of Al2O3film. Microstructure characterization indicates that the film surface at low substrate temperature is smoother, and the surface roughness of these Al2O3films is in the range 1-6 nm. The residual stress increases with increasing the substrate temperature, while the stress decreases after annealing in N2condition. It also can be concluded that the microstructure is correlated with residual stress.

scholarly journals Effect of Oxygen Flow Rate on the Optical, Electrical, and Mechanical Properties of DC Sputtering ITO Thin Films

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Chuen-Lin Tien ◽  
Hong-Yi Lin ◽  
Chih-Kai Chang ◽  
Chien-Jen Tang
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Surface Roughness ◽  
Flow Rate ◽  
Optical Transmittance ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
Ito Thin Films ◽  
Effect Of Oxygen

This study presents the effect of oxygen flow rate on the optical, electrical, and mechanical properties of indium tin oxide (ITO) thin films prepared by the DC magnetron sputtering technique. The oxygen flow rate was varied from 10 to 50 sccm. The ITO thin films deposition under different oxygen flow rates exhibits different properties. We used an optical spectrometer to measure the optical transmittance and a four-point probe instrument to determine the resistivity. A home-made Twyman-Green interferometer was used to evaluate residual stress and a microscopic interferometer was used to measure the surface roughness of ITO thin films. The experimental results show that the average optical transmittance is larger than 85% in visible range; the electrical resistivity has a minimum 6.85×10-4 ohm-cm for the oxygen flow of 10 sccm. The residual stress is varied from −0.15 GPa to −0.34 GPa in the range of 10–50 sccm. The root-mean-square (rms) surface roughness is changed from 2.64 nm to 2.74 nm as the oxygen flow rate increases. The results show that the oxygen flow rate has significant influence on the electrical resistivity, residual stress, and surface roughness of the ITO thin film.

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