scholarly journals Создание равномерных покрытий импульсным лазерным осаждением

2021 ◽  
Vol 57 (6) ◽  
pp. 25-35
Author(s):  
Н. И. Анякин ◽  
◽  
Р. О. Жук ◽  
Е. В. Проценко ◽  
В. С. Коваленко ◽  
...  
Keyword(s):  
Laser Beam ◽  
Processing Parameters ◽  
Work Piece ◽  
Uniform Illumination ◽  
Large Area ◽  
Thin Coatings ◽  
Minimal Deviation ◽  
Direct Dependency ◽  
Selection Of ◽  
Beam Deposition

The present paper deals with the selection of laser beam processing parameters that guarantee the formation of thin coatings with even thickness by means of the laser beam deposition. Laser deposition was carried out in the atmosphere of Ar and Si and SiC samples were used as a source for the deposited material. Preliminary experiments show that there is a direct dependency between the brightness of the image of the deposited layer (at uniform illumination conditions) and its thickness. Therefore, it was possible to determine the thickness of the deposited layer for various processing parameters and to calculate the laws of motion of the work piece that guarantee the deposition of the layer with a minimal deviation of thickness from the required value. Calculated parameters were successfully used for the deposition of coatings on a substrate of a relatively large area.

scholarly journals Mechanical and Metallurgical Characterisation of CO2 Laser Beam Welding AISI 4130 and AISI 310 Sheets of Steel

2021 ◽  
Vol 71 (2) ◽  
pp. 19-30
Author(s):  
Bijivemula Narayana Reddy ◽  
Pothur Hema ◽  
Chevireddy Eswara Reddy
Keyword(s):  
Laser Beam ◽  
Focal Point ◽  
Focal Length ◽  
Weld Zone ◽  
Laser Beam Welding ◽  
Processing Parameters ◽  
Fusion Welding ◽  
Work Piece ◽  
Steel Aisi ◽  
Aisi 4130

Abstract Laser Beam Welding (LBW) is the fusion welding technique in which coalescence is produced by heating the work piece by impingement of concentrated beam of laser light. In this paper a full depth butt welding of alloy steel AISI 4130 and stainless steel AISI 310 of 2 mm thickness by using CO2 Laser Beam Welding machine has been performed. Design of experiment is done by using Taguchi method L25 i.e. level 5 by considering process parameters i.e. power, welding speed, beam angle, focal point position and focal length. The experimental output results that are measured for the mechanical properties of welds (Ultimate Tensile Strength and Hardness). The analysis was carried out to explain the influence of the LBW processing parameters values on the mechanical and microstructural aspects. The weld Joint is analysed by Optical Microstructure and Scanning Electron Microscopy (SEM). The Energy Dispersive X-Ray Analysis (EDAX) was carried out to determinate the chemical composition of the weld zone.

High Resolution Displacement of Functional Groups onto Fluorocarbon Resin Surface by Using ArF Excimer Laser

1996 ◽  
Vol 451 ◽  
Author(s):  
T. Shimizu ◽  
M. Murahara
Keyword(s):  
Contact Angle ◽  
High Resolution ◽  
Laser Beam ◽  
Thin Layer ◽  
Functional Groups ◽  
Excimer Laser ◽  
Laser Fluence ◽  
Large Area ◽  
Three Solutions ◽  
Arf Excimer Laser

ABSTRACTA Fluorocarbon resin surface was selectively modified by irradiation with a ArF laser beam through a thin layer of NaAlO2, B(OH)3, or H2O solution to give a hydrophilic property. As a result, with low fluence, the surface was most effectively modified with the NaAlO2 solution among the three solutions. However, the contact angle in this case changed by 10 degrees as the fluence changed only 1mJ/cm2. When modifying a large area of the surface, high resolution displacement could not be achieved because the laser beam was not uniform in displacing functional groups. Thus, the laser fluence was successfully made uniform by homogenizing the laser beam; the functional groups were replaced on the fluorocarbon resin surface with high resolution, which was successfully modified to be hydrophilic by distributing the laser fluence uniformly.

scholarly journals Rapid Single Image-Based DTM Estimation from ExoMars TGO CaSSIS Images Using Generative Adversarial U-Nets

2021 ◽  
Vol 13 (15) ◽  
pp. 2877
Author(s):  
Yu Tao ◽  
Siting Xiong ◽  
Susan J. Conway ◽  
Jan-Peter Muller ◽  
Anthony Guimpier ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Imaging System ◽  
Landing Site ◽  
Parameter Tuning ◽  
Processing Parameters ◽  
Input Image ◽  
Large Area ◽  
Laser Altimeter ◽  
Imaging Science

The lack of adequate stereo coverage and where available, lengthy processing time, various artefacts, and unsatisfactory quality and complexity of automating the selection of the best set of processing parameters, have long been big barriers for large-area planetary 3D mapping. In this paper, we propose a deep learning-based solution, called MADNet (Multi-scale generative Adversarial u-net with Dense convolutional and up-projection blocks), that avoids or resolves all of the above issues. We demonstrate the wide applicability of this technique with the ExoMars Trace Gas Orbiter Colour and Stereo Surface Imaging System (CaSSIS) 4.6 m/pixel images on Mars. Only a single input image and a coarse global 3D reference are required, without knowing any camera models or imaging parameters, to produce high-quality and high-resolution full-strip Digital Terrain Models (DTMs) in a few seconds. In this paper, we discuss technical details of the MADNet system and provide detailed comparisons and assessments of the results. The resultant MADNet 8 m/pixel CaSSIS DTMs are qualitatively very similar to the 1 m/pixel HiRISE DTMs. The resultant MADNet CaSSIS DTMs display excellent agreement with nested Mars Reconnaissance Orbiter Context Camera (CTX), Mars Express’s High-Resolution Stereo Camera (HRSC), and Mars Orbiter Laser Altimeter (MOLA) DTMs at large-scale, and meanwhile, show fairly good correlation with the High-Resolution Imaging Science Experiment (HiRISE) DTMs for fine-scale details. In addition, we show how MADNet outperforms traditional photogrammetric methods, both on speed and quality, for other datasets like HRSC, CTX, and HiRISE, without any parameter tuning or re-training of the model. We demonstrate the results for Oxia Planum (the landing site of the European Space Agency’s Rosalind Franklin ExoMars rover 2023) and a couple of sites of high scientific interest.

Influence of Thermal Deformations in the Solid Laser Medium on the Emitted Radiation Parameters

2005 ◽  
Vol 219 (8) ◽  
pp. 823-827
Author(s):  
O Donţu ◽  
S Ganatsios ◽  
D Duminica
Keyword(s):  
Laser Beam ◽  
Radial Distribution ◽  
Thermal Deformation ◽  
Processing Parameters ◽  
Beam Intensity ◽  
Laser Medium ◽  
Laser Beam Intensity ◽  
Active Laser ◽  
Thermal Deformations ◽  
Active Laser Medium

The paper presents some remarks about the way in which the thermal deformation in the solid active laser medium influences the radial distribution of the emitted laser beam intensity, implicitly the processing parameters.

FABRICATION OF POLYMER MASTER FOR ANTIREFLECTIVE SURFACE USING HOT EMBOSSING AND AAO PROCESS

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5887-5894 ◽  
Author(s):  
HONG GUE SHIN ◽  
JONG TAE KWON ◽  
YOUNG HO SEO ◽  
BYEONG HEE KIM
Keyword(s):  
Aspect Ratio ◽  
Silicon Layer ◽  
Processing Parameters ◽  
Hot Embossing ◽  
Large Area ◽  
Anodized Aluminum ◽  
Simple Method ◽  
Anodized Aluminum Oxide ◽  
Coating Method ◽  
Automobile Components

A simple method for the fabrication of polymer master for antireflective surface is presented. In conventional fabrication methods for antireflective surface, coating method with low refractive index have usually been used. However, it is required to have a high cost and a long processing time for mass production. In this paper, antireflective surface was fabricated by using hot embossing process with porous anodized aluminum oxide. Through multi-AAO and etching processes, nano patterned master with high aspect ratio was fabricated at the large area. Size and aspect ratio of nano patterned master are about 175 ± 25 nm and 2 ~ 3, respectively. In order to replicate nano patterned master, hot embossing process was performed by varying the processing parameters such as temperature, pressure and embossing time etc. Finally, antireflective surface can be successfully obtained after etching process to remove selectively silicon layer of AAO master. Optical and rheological characteristics of antireflective surface were analyzed by using SEM, EDX and spectrometer inspection. Antireflective structure by replicating hot embossing process can be applied to various displays and automobile components.

Large Area DPB Free (111) β-SiC Thick Layer Grown on (0001) α-SiC Nominal Surfaces by the CF-PVT Method

2005 ◽  
Vol 483-485 ◽  
pp. 225-228 ◽  
Author(s):  
Didier Chaussende ◽  
Laurence Latu-Romain ◽  
Laurent Auvray ◽  
M. Ucar ◽  
Michel Pons ◽  
...  
Keyword(s):  
Growth Rate ◽  
Optical Microscopy ◽  
Cross Section ◽  
Thick Layer ◽  
Vapour Transport ◽  
Large Area ◽  
Continuous Feed ◽  
Heating Up ◽  
Cross Section Geometry ◽  
Selection Of

Thick (111) oriented β-SiC layers have been grown by hetero-epitaxy on a (0001) a-SiC substrate with the Continuous Feed-Physical Vapour Transport (CF-PVT) method. The growth rate was 68 µm/h at a pressure of 2 torr and a temperature of 1950°C. The nucleation step of the β-SiC layer during the heating up of the process was studied in order to manage first the a to b heteropolytypic transition and second the selection of the b-SiC orientation. With a adapted seeding stage, we grew a 0.4mm thick layer almost free of Double Positioning Boundaries on a 30mm diameter sample. First observations of the layer by cross-polarised optical Microscopy are presented both in planar view and in cross section geometry.

Mass selection of neutral clusters in Low‐Energy Cluster Beam Deposition experiments: Is it realistic?

1994 ◽  
Vol 64 (10) ◽  
pp. 1212-1214 ◽  
Author(s):  
J. F. Roux ◽  
B. Cabaud ◽  
G. Fuchs ◽  
D. Guillot ◽  
A. Hoareau ◽  
...  
Keyword(s):  
Low Energy ◽  
Mass Selection ◽  
Cluster Beam ◽  
Cluster Beam Deposition ◽  
Energy Cluster ◽  
Selection Of ◽  
Beam Deposition

scholarly journals Studies on friction behaviour of aluminium AA4032 alloy during forging using ring compression test

2021 ◽  
Vol 13 (3) ◽  
pp. 23-36
Author(s):  
Desalegn Wogaso ◽  
Mohammed Hamda
Keyword(s):  
Friction Factor ◽  
Metal Surface ◽  
Palm Oil ◽  
Compression Test ◽  
Metal Flow ◽  
Work Piece ◽  
Ring Compression Test ◽  
Ring Compression ◽  
Friction Behaviour ◽  
Selection Of

In metal forming, friction has a negative effect on the deformation load & energy requirements, homogeneity of metal flow, quality of formed surfaces, etc.; however, its effect can be reduced through the use of proper lubricants. Mostly, in industrial applications, selection of proper lubricant for specific material is challenging and quantification of magnitude of friction at diework piece interface is essential. Hence, for metallic alloys, a realistic friction factor is needed to be known and used at the diework piece interface for better control of deformation process. Thus, this research, generally, aims at experimental investigation of the friction behavior of aluminum AA4032 alloy and selection of suitable lubricant for its effective processing using ring compression test and finite element (FE) simulations. Meanwhile, the effect of metal surface conditions and different lubricants namely palm oil, grease, emulsion oil and dry conditions on the friction behaviour has been evaluated. A commercial FEM software, DEFORM 3D, is used to analyze the flow of metal, determine the geometry changes of the specimen and generate friction calibration curves. The results revealed that the nature of metal surface and lubricating conditions have significantly affected the metal flow pattern, deformation load requirement, induced effective stress and strain, and geometry of the metal. The friction factor at die-work piece is determined for different lubricating conditions. Among lubricants employed, palm oil is found to be suitable and effective for industrial processing of aluminium AA4032 alloy, specifically for forging. The FE simulation results are in a good agreement with the experimental one.

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