scholarly journals Fabrication of superhydrophilic surfaces for long time preservation on 316L stainless steel by ultraviolet laser etching

2022 ◽  
Author(s):  
Chunyang Pan ◽  
Changfeng Xu ◽  
Jun Zhou
Keyword(s):  
Stainless Steel ◽  
Process Parameters ◽  
316L Stainless Steel ◽  
Scanning Speed ◽  
Textured Surface ◽  
Laser Process ◽  
Maintenance Time ◽  
316L Steel ◽  
Long Time ◽  
Good Biocompatibility

Abstract Due to the good biocompatibility, 316L stainless steel is widely used in the manufacture of medical instru-ments and human implants. The super hydrophilic 316L steel surface is used for reducing friction and adhe-sion. By choosing appropriate laser process parameters 316L steel surfaces with super-hydrophilic were ob-tained. The effects of laser process parameters including repeat frequency, pulse width, scanning speed, and the number of scanning were investigated to find the relationship between surface microstructure and wet-ting ability. To investigate the super-hydrophilic maintenance time on the textured surface, the textured sur-faces were preserved in ambident air, distilled water, and absolute ethanol. The results showed that by choosing appropriate laser process parameters surface with super-hydrophilicity can be maintained for 30 days.

Influence of the Temperature in the Direct Forming Laser Process of 316L Stainless Steel with CO2 Laser

2014 ◽  
Vol 802 ◽  
pp. 334-337
Author(s):  
C.L. Santos ◽  
G. Vasconcelos ◽  
H.S. Oliveira ◽  
L.G. Oliveira ◽  
J.F. Azevedo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Melting Point ◽  
Laser Beam ◽  
316L Stainless Steel ◽  
Turbine Blades ◽  
Scanning Speed ◽  
Sample Surface ◽  
Laser Process

This study shows the influence of the temperature in the Direct Forming Laser process (DFL) of 316L stainless steel metal powder. Results shows that an increasing in the sample surface temperature can improve the laser beam absorption in the DFL process. A pre-heating in the substrate and in the powder contributed to decrease the time to reach the melting point and to improve the surface roughness. This effect was investigated with constant lasers parameters (scanning speed and intensity) and a heating in the samples in the temperature range of 20oto 200oC. It was possible to evaluate the DFL process and to optimize the quality of the sample surface roughness. These results will benefit the knowledge of the DFL technology that can be applied in the development of turbine blades.

scholarly journals Forming Process, Microstructure, and Mechanical Properties of Thin-Walled 316L Stainless Steel Using Speed-Cold-Welding Additive Manufacturing

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 109 ◽  
Author(s):  
Wei Wu ◽  
Jiaxiang Xue ◽  
Leilei Wang ◽  
Zhanhui Zhang ◽  
Yu Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
316L Stainless Steel ◽  
Scanning Speed ◽  
Cooling Time ◽  
Bottom Current ◽  
Cold Welding ◽  
Thin Walled

Wire and arc additive manufacturing (WAAM) produces thin-walled parts superior to other additive manufacturing methods, because of its high efficiency, good compactability, and low cost. However, the WAAM accuracy is limited by its large heat input. Here, 0.8 mm 316L stainless steel welding wire is deposited via speed cold welding to form 30-layered thin-walled samples, with 2 mm thickness, and up to 65 mm height. The effects of three process parameters (the bottom current mode, scanning speed, and cooling time) on the deposition process stability, macro morphology, structure, and mechanical properties are studied. In the experiment, the probability density curves of electrical parameters of sample #GRBC-30 cm/min-10 s on the third and tenth layers were narrower than other samples, which implied a more stable process. The three process parameters mainly affect the deposition morphology and have a minor performance effect. The hardness and tensile properties mainly depend on the deposition direction. Gradual, layer-by-layer current reduction improves the bottom molding and performance, and the deposition efficiency, and stabilizes the process. Scanning speed enhancement or cooling time reduction destabilizes the end formation, reduces the effective deposition rate, and slightly degrades the performance. All deposited samples are distinctly anisotropic, but satisfy the industrial standard. Overall, deposition in speed cold welding mode, with 10 s cooling time, 30 cm/min scanning speed, and gradually reduced bottom current exhibits good stability, and the molding efficiency and mechanical properties are optimal.

Determination of Optimum Parameters Effect on Kerf Width of 316L Stainless Steel Tube in Nd:YAG Laser Cutting

2005 ◽  
Vol 475-479 ◽  
pp. 277-280
Author(s):  
J.M. Ahn ◽  
H.Y. Kim ◽  
T.H. Kim
Keyword(s):  
Stainless Steel ◽  
Cooling Rate ◽  
Process Parameters ◽  
Laser Power ◽  
316L Stainless Steel ◽  
Scanning Speed ◽  
Steel Tube ◽  
Gas Pressure ◽  
Kerf Width ◽  
Stainless Steel Tube

The effects of following four factors, which are laser power, assist gas pressure, cooling rate and scanning speed on the quality characteristics of laser cut 316L stainless steel tubes have been studied. 24 full factorial design and central composite design were used to evaluate optimum condition of process parameters. Regression analysis was used to develop empirical models for the combined effects of the independent process parameters on laser cut quality. As the results, it was observed that laser power, assist gas pressure and scanning speeds did the major effects on kerf width. The smallest kerf width was obtained with the condition of low laser power, assist gas pressure, scanning speed and moderate cooling rate. Calculated regression model was kerf width = 64.47 + 0.91W + 1.25P + 0.41S + 0.41C2 - 0.45P2

scholarly journals Analysis of the Process Parameter Influence in Laser Cladding of 316L Stainless Steel

2018 ◽  
Vol 2 (3) ◽  
pp. 55 ◽  
Author(s):  
Piera Alvarez ◽  
M. Montealegre ◽  
Jose Pulido-Jiménez ◽  
Jon Arrizubieta
Keyword(s):  
Stainless Steel ◽  
Laser Cladding ◽  
Process Parameters ◽  
Cross Sections ◽  
316L Stainless Steel ◽  
Deposition Process ◽  
Process Parameter ◽  
Optimum Process ◽  
Processing Times ◽  
Manufacturing Technologies

Laser Cladding is one of the leading processes within Additive Manufacturing technologies, which has concentrated a considerable amount of effort on its development. In regard to the latter, the current study aims to summarize the influence of the most relevant process parameters in the laser cladding processing of single and compound volumes (solid forms) made from AISI 316L stainless steel powders and using a coaxial nozzle for their deposition. Process speed, applied laser power and powder flow are considered to be the main variables affecting the laser cladding in single clads, whereas overlap percentage and overlapping strategy also become relevant when dealing with multiple clads. By setting appropriate values for each process parameter, the main goal of this paper is to develop a processing window in which a good metallurgical bond between the delivered powder and the substrate is obtained, trying simultaneously to maintain processing times at their lowest value possible. Conventional metallography techniques were performed on the cross sections of the laser tracks to measure the effective dimensions of clads, height and width, as well as the resulting dilution value. Besides the influence of the overlap between contiguous clads and layers, physical defects such as porosity and cracks were also evaluated. Optimum process parameters to maximize productivity were defined as 13 mm/s, 2500 W, 30% of overlap and a 25 g/min powder feed rate.

Effects of process parameters, debinding and sintering on the microstructure of 316L stainless steel produced by binder jetting

2021 ◽  
pp. 142108
Author(s):  
Nora Lecis ◽  
Marco Mariani ◽  
Ruben Beltrami ◽  
Lorena Emanuelli ◽  
Riccardo Casati ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Process Parameters ◽  
316L Stainless Steel ◽  
Binder Jetting

scholarly journals Improving the Corrosion Resistance of AISI 316L Steel for Semiconductor Piping by Controlled Delta-Ferrite Content

2022 ◽  
Vol 60 (1) ◽  
pp. 46-52
Author(s):  
Young Woo Seo ◽  
Chan Yang Kim ◽  
Bo Kyung Seo ◽  
Won Sub Chung
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
316L Stainless Steel ◽  
Sem Analysis ◽  
Ferrite Content ◽  
Aisi 316L ◽  
Delta Ferrite ◽  
Aisi 316L Stainless Steel ◽  
316L Steel ◽  
The Difference

This study evaluated changes in delta-ferrite content depending on the preheating of AISI 316L stainless steel. We also determined the reasons for the variation in delta-ferrite content, which affects corrosion resistance. Changes in delta-ferrite content after preheating was confirmed using a Feritscope, and the microstructure was analyzed using optical microscopy (OM). We found that the delta-ferrite microstructure size decreased when preheating time was increased at 1295 oC, and that the delta-ferrite content could be controlled through preheating. Potentiodynamic polarization test were carried out in NaCl (0.5 M) + H2SO4 (0.5 M) solution, and it was found that higher delta-ferrite content resulted in less corrosion potential and passive potential. To determine the cause, an analysis was conducted using energy-dispersive spectroscopy (EDS), which confirmed that higher delta-ferrite content led to weaker corrosion resistance, due to Cr degradation at the delta-ferrite and austenite boundaries. The degradation of Cr on the boundaries between austenite and delta-ferrite can be explained by the difference in the diffusion coefficient of Cr in the ferrite and austenite. A scanning electron microscopy (SEM) analysis of material used for actual semiconductor piping confirmed that corrosion begins at the delta-ferrite and austenite boundaries. These results confirm the need to control delta-ferrite content in AISI 316L stainless steel used for semiconductor piping.

scholarly journals Influence of Scanning Strategy Parameters on Residual Stress in the SLM Process According to the Bridge Curvature Method for AISI 316L Stainless Steel

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1659 ◽  
Author(s):  
Jiri Hajnys ◽  
Marek Pagáč ◽  
Jakub Měsíček ◽  
Jana Petru ◽  
Mariusz Król
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Process Parameters ◽  
316L Stainless Steel ◽  
Stress Generation ◽  
Aisi 316L ◽  
Laser Melting ◽  
Scanning Strategy ◽  
Aisi 316L Stainless Steel ◽  
Strategy Parameters

The present paper deals with the investigation and comparison of the influence of scanning strategy on residual stress in the selective laser melting (SLM) process. For the purpose of the experiment, bridge geometry samples were printed by a 3D metal printer, which exhibited tension after cutting from the substrate, slightly bending the samples toward the laser melting direction. Samples were produced with the variation of process parameters and with a change in scanning strategy which plays a major role in stress generation. It was evaluated using the Bridge Curvature Method (BCM) and optical microscopy. At the end, a recommendation was made.

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