scholarly journals Influence of ns-Laser Cleaning Parameters on the Removal of the Painted Layer and Selected Properties of the Base Metal

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5363
Author(s):  
Xinyan Li ◽  
Dan Wang ◽  
Juming Gao ◽  
Weiwei Zhang ◽  
Canyang Li ◽  
...  
Keyword(s):  
Base Metal ◽  
Three Dimensional ◽  
Hardness Test ◽  
Scanning Speed ◽  
Laser Cleaning ◽  
Laser Source ◽  
Maximum Hardness ◽  
Fine Grain ◽  
Electron Back Scattered Diffraction ◽  
Painted Layer

The removal of the surface paint of Q345 (Gr·B) steel, as well as microstructure and hardness of the cleaned surface were investigated. The laser source used in this study is a nanosecond pulsed Gaussian light source. The surface morphology and microstructure were characterized by a scanning electron microscope and electron back-scattered diffraction. A hardness test was used for capturing variations of the parameter of the cleaned region in comparison to the base metal. The results show that when the X-scanning speed was 1500 mm/s and Y-moving speeds was 7 mm/s during ns-laser cleaning, respectively, the cleaned surface was relatively flat and there was only a few small residual paint. In addition, the contents of Fe and C elements on the cleaned surface reached to 89% and 9%, respectively. Moreover, the roughness was the lowest of 0.5 μm through the observation of the three-dimensional topography. In addition, a fine grain layer appeared on the cleaned surface after laser cleaning at the X-scanning speeds of 500 mm/s and 1000 mm/s. The maximum hardness of the fine grain layer was more than 400 HV, higher than the base metal.

The Effect of Stand - Off Distance on the Mechanical Properties of TIG Butt Joints of 316 Stainless Steel

2020 ◽  
Vol 833 ◽  
pp. 59-65
Author(s):  
Hala M. Gnedi ◽  
Khawla T. Snoussi ◽  
Abulmaali M. Taher ◽  
Thoria G. Sharef ◽  
Yousef Arebi
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Base Metal ◽  
Welded Joints ◽  
Hardness Test ◽  
Scanning Speed ◽  
Geometrical Parameters ◽  
Worst Case ◽  
316 Stainless Steel ◽  
Hardness Values

The objective of this study is to investigate and determine the effect of the stand-off distance (distance between the welded plates) on the mechanical properties of the Tungsten Inert Gas (TIG) welded joints. Butt TIG welding was performed for 316 stainless steel (SS) by using different pre welding stand-off distances with fixing the other parameters (thickness of welded plates, voltage, current, groove shape, and scanning speed). The influence of the stand-off distance parameter was examined by using tensile test, hardness test in the three different regions (base metal, heat effected zone, and molten zone), non-destructive testing (including visual inspection, liquid pentrant and X – ray) and microscopic examinations. Results show that the stand-off distance is one of the most important geometrical parameters of the Butt welded joints to end by good mechanical properties. It is found that the optimum stand-off distance was about 1 mm (shows the highest hardness results), but still there were some defects in some spots in the molten metal zone which caused a decrease in the hardness values in these locations. The 2 mm stand-off distance shows reasonable results, and the worst case was recorded for the 0 mm stand-off distance condition. Generally the hardness values of the heat affected zone in all conditions were the highest when compared to both metal welding zone and the base metal zone.

scholarly journals Time efficient laser modification of steel surfaces for advanced bonding in hybrid materials

2020 ◽  
Author(s):  
D. Voswinkel ◽  
D. Kloidt ◽  
O. Grydin ◽  
M. Schaper
Keyword(s):  
Adhesive Bonding ◽  
Scanning Speed ◽  
Laser Source ◽  
Lap Shear ◽  
Carbon Fibre Reinforced Polymer ◽  
Bonding Properties ◽  
Fibre Reinforced Polymer ◽  
Yvo4 Laser ◽  
Steel Surfaces ◽  
High Scanning Speed

AbstractLaser surface treatment of metals is one option to improve their properties for adhesive bonding. In this paper, a pulsed YVO4 Laser source with a wavelength of 1064 nm and a maximum power of 25 W was utilized to increase the surface area of the steel HCT490X in order to improve its bonding properties with a carbon fibre reinforced polymer (CFRP). Investigated was the influence of the scanning speed of the laser source on the bonding properties. For this purpose, the steel surfaces were ablated at a scanning speed between 1500 and 4500 mm/s. Afterwards the components were bonded with the adhesive HexBond™ 677. After lap shear tests were carried out on the specimen, the surfaces were inspected using scanning electron microscopy (SEM). The experiments revealed that the bonding quality can be improved with a high scanning speed, even when the surface is not completely ablated.

The Method of Eliminating Banded Structure and the Effects of Banded Structure on the Transverse Properties in 20G Steel

2013 ◽  
Vol 347-350 ◽  
pp. 1171-1175 ◽  
Author(s):  
Bin Wang ◽  
Hong Mei Hu ◽  
Cui Zhou
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Stress Concentration ◽  
Base Metal ◽  
Metallic Inclusion ◽  
Banded Structure ◽  
Grain Sizes ◽  
Fine Grain ◽  
Treatment Processes ◽  
Metallic Inclusions

The transverse properties were inferior to the longitudinal properties for the existence of banded structure in 20G steel. In order to eliminate the banded structure and improve the transverse performance of 20G steel, different heat treatment processes were adopted. The results showed that conventional normalizing could reduce the banded structure and refine the grain sizes. When 20G was heated with 10°C/min heating rated and then held at 920°C for 2h, the banded structure in the steel was almost eliminated and the microstructure was homogeneous with fine grain size, the strength increased by 14%. The non-metallic inclusion and carbide in the microstructure leaded to stress concentration and separation with the base metal. To some extent, heat treatment can improve the distribution and form of non-metallic inclusions.

Investigations of The Hybrid Effects of The Operational Parameters In The Radial Forging Process Based On The Validation of The Hardness Test

2022 ◽  
Author(s):  
Saeed Darki ◽  
Evgeniy Yurevich Raskatov
Keyword(s):  
Effective Strain ◽  
Three Dimensional ◽  
Hardness Test ◽  
Radial Forging ◽  
Operational Parameters ◽  
Three Dimensional Model ◽  
Temperature Changes ◽  
Forging Process ◽  
Specimen Tube ◽  
Radial Forging Process

Abstract In this study, considering all the parameters in radial forging and a three-dimensional model has been simulated using the finite element method. By implementing an elastoplastic state for the specimen tube, parameters such as friction type, residual stress distribution, effective strain distribution, material flow velocity and its effect on the neutral plate and the distribution of force in the die have been studied and analyzed. The effects of angle on the quality and characteristics of the specimen and the longevity of the die have also been obtained. Experimental results have been used to confirm the accuracy of the simulation. The results of the hardness test after forging were compared with the simulation results. Good agreement between the results indicates the accuracy of the simulation in terms of hardness. Therefore, this validation allows confirming the other obtained results for the analysis and prediction of various components in the forging process. After the validation and confirmation of the results through the hardness test, the hardness distribution was obtained by considering temperature changes and the effective strain on the specimen.

On three-dimensional printing of 17-4 precipitation-hardenable stainless steel with direct metal laser sintering in aircraft structural applications

2021 ◽  
pp. 146442072110448
Author(s):  
Rupinder Singh ◽  
Rishab ◽  
Jashanpreet S Sidhu
Keyword(s):  
Stainless Steel ◽  
Structural Engineering ◽  
Three Dimensional ◽  
Surface Hardness ◽  
Dimensional Accuracy ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Structural Components ◽  
Direct Metal Laser Sintering ◽  
Structural Applications

The martensitic 17-4 precipitation-hardenable stainless steel is one of the commercially established materials for structural engineering applications in aircrafts due to its superior mechanical and corrosion resistance properties. The mechanical processing of this alloy through a conventional manufacturing route is critical from the dimensional accuracy (Δ d) viewpoint for development of innovative structural components such as: slat tracks, wing flap tracks, etc. In past two decades, a number of studies have been reported on challenges being faced while conventional processing of 17-4 precipitation-hardenable stainless steel for maintaining uniform thickness of aircraft structural components. However, hitherto little has been reported on direct metal laser sintering of 17-4 precipitation-hardenable stainless steel for development of innovative functional prototypes with uniform surface hardness (HV), Δ d, and surface roughness ( Ra) in aircraft structural engineering. This paper reports the effect of direct metal laser sintering process parameters on HV, Δ d, and Ra for structural components. The results of study suggest that optimized settings of direct metal laser sintering from multifactor optimization viewpoint are laser power 100 W, scanning speed 1400 mm/s, and layer thickness 0.02 mm. The results have been supported with scanning electron microscopy analysis (for metallurgical changes such as porosity (%), HV, grain size, etc.) and international tolerance grades for ensuring assembly fitment.

scholarly journals PENINGKATAN SIFAT MEKANIS BESI COR KELABU MELALUI PROSES TEMPERING

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
A. Noor Setyo HD ◽  
Sri Widodo
Keyword(s):  
Cold Water ◽  
Hardness Test ◽  
Heating Time ◽  
Initial Energy ◽  
Test Results ◽  
Maximum Hardness ◽  
Quenching Temperature ◽  
Independent Variables ◽  
Hardness Tester ◽  
Water Media

This study aims to determine the Hardness and Toughness of cast iron after undergoing a Tempering process with independent variables heating time and dependent Hardness, microstructure and toughness Impack. Quenching was carried out at temperatures of 7750C, 8000C and 8250C in cold water media, while Tempering was carried out at temperatures of 2000C, 3000C and 4000C with a holding time of 15 minutes. Vickers Hardness test results using "Micro Hardness Tester" after Quenching have increased by an average of 95.6% at Quenching 7750C, 99.8% at Quenching 8000C and 107.1% at Quenching temperature 8250C from Hardness value of row material of 256.6 BHN or 260.8 VHN0,040. The maximum hardness value is obtained 531.4 BHN or 553.6 VHN 0,040 at Quenching temperature 8250C and the lowest Hardness of 501.8 BHN or 541,8 VHN0,040 at Quenching 7750C temperature, has Cementite phase as a matrix with little Martensite, is due to treatment The partial tempering of Martensite is replaced by the ferrite phase between Cementites. The results of the study concluded that at Tempering temperatures of 2000C, 3000C and 4000C, the toughness of FC 30 experienced an increase of 106.5%, 121.9% and 130.5% from the initial energy of 5.21 Joule / mm2, whereas violence decreased by 88, 6%, 80.8% and 40.4% of the original Hardness of 260.8 VHN 0,040

scholarly journals Estimation of the compression strength and surface roughness of the as-built SLS components using weibull distribution

2021 ◽  
pp. 1-6
Author(s):  
Hamaid Mahmood KHAN
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Compressive Strength ◽  
Weibull Distribution ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Random Variable ◽  
Production Quality ◽  
Laser Source ◽  
Distribution Method

Selective laser sintering (SLS) is a process of fabrication of three-dimensional structures by fus- ing powder particles using a guided laser source. The uncertainty in the mechanical properties of the SLS parts fabricated at the same time and with the same process parameters can affect the repeatability of the SLS process. A vast difference in the mechanical properties of the concurrently processed parts can lower the production quality of the batch. Therefore, the param- eters are required to be design based on the most probable outcome of the desired properties. Weibull distribution is one such statistical-based probability distribution method to measure the likelihood of the occurrence of a value of any random variable falling within a particular range of values. Here, the Weibull distribution was used to measure the relative likelihood (90% probability) of the surface roughness and the compressive strength values of the SLS-built polyamide PA2200 components in the given sample space that was obtained from 20 random samples. The results show that the variance in the surface roughness (scan and built plane) and the compressive strength values were in the range of 6–7 μm and around 10 MPa, respectively. Moreover, the surface roughness of the two orthogonal planes with 90% reliability was measured at 14.81 μm (scan plane) and 12.15 μm (built plane). Similarly, the yield strength and the compressive strength with 90% reliability were found 25.87 MPa and 62.64 MPa, respectively.

Three-dimensional effects in dry laser cleaning

2003 ◽  
Vol 77 (2) ◽  
pp. 209-215 ◽  
Author(s):  
B.S. Luk‘yanchuk ◽  
N. Arnold ◽  
S.M. Huang ◽  
Z.B. Wang ◽  
M.H. Hong
Keyword(s):  
Three Dimensional ◽  
Laser Cleaning ◽  
Dimensional Effects

scholarly journals Utilization of rapid prototyping technology for the fabrication of an orthopedic shoe inserts for foot pain reprieve using thermo-softening viscoelastic polymers: A novel experimental approach

2020 ◽  
Vol 53 (3-4) ◽  
pp. 519-530
Author(s):  
Shubham Sharma ◽  
Jujhar Singh ◽  
Harish Kumar ◽  
Abhinav Sharma ◽  
Vivek Aggarwal ◽  
...  
Keyword(s):  
Rapid Prototyping ◽  
Thermoplastic Polyurethane ◽  
Research Work ◽  
Testing Machine ◽  
Three Dimensional ◽  
Hardness Test ◽  
Thermoplastic Elastomer ◽  
Bending Test ◽  
Foot Orthosis ◽  
Orthotic Insoles

This research work has been completed by concentrating on the structure of inserts for foot orthosis fabricated by utilizing rapid prototyping technology. Thermoplastic elastomer and thermoplastic polyurethane are the most commonly used materials that are being used in customized three-dimensional printed orthotic insoles, which are comfortable and prevent the user in many foot disorders. Thermo-softening viscoelastic polymers, explicitly Filaflex and Ninjaflex, have been printed by utilizing Flash Forge three-dimensional printers to evaluate the mechanical properties of specimens with alterations of the percentage rate fill-up design replicas. The results are compared on the basis of hardness test, flexural/bending test, and tensile test using Durometer and Universal Testing Machine (UTM). It has also been observed that the most significant effecting factor is infill density.

scholarly journals Application of laser remote sensing technology and super continuous spectrum laser

2020 ◽  
Vol 165 ◽  
pp. 03002
Author(s):  
Li Jing ◽  
Che Ying ◽  
Jin Meishan ◽  
Zhai Yannan ◽  
Ding Changhong
Keyword(s):  
Remote Sensing ◽  
Continuous Spectrum ◽  
Oil Spill ◽  
Three Dimensional ◽  
High Energy ◽  
High Energy Density ◽  
Laser Radar ◽  
Laser Source ◽  
Spectral Information ◽  
Distant Target

Fiber optic super continuous spectrum laser technology is a new technology developed in recent years. It takes into account the advantages of good alignment of laser source, high energy density and wide wavelength range of ordinary white light source, which can not only accurately remote sense distant target, but also obtain hyperspectral information of distant target. Super continuous spectrum of laser radar is a kind of remote sensing monitoring instrument, it can obtain three-dimensional spectral information of the target, and can be accurately detected in the night of distant high spectral information, the all-weather, three-dimensional spectrum detection method with the traditional passive remote sensing compared with single/multiband laser radar technology has incomparable advantages. Based on the development trend of lidar abroad, the development status of super-continuous spectrum lidar in China and the problems in remote sensing detection of oil spill, this paper introduces the feasibility of using super-continuous spectrum laser to monitor oil spill in the sea, which lays a foundation for further research.

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