scholarly journals A steady-state semi-analytical approximation of melt pool evolution in pulsed laser surface melting

2022 ◽  
Vol 74 ◽  
pp. 123-135
Author(s):  
Utsavkumar Mistry ◽  
Madhu Vadali
Keyword(s):  
Steady State ◽  
Pulsed Laser ◽  
Analytical Approximation ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Melt Pool

scholarly journals A Steady State Semi-analytical Approximation of Melt Pool Evolution in Pulsed Laser Surface Melting

2021 ◽  
Author(s):  
Utsavkumar Mistry ◽  
Madhu Vadali
Keyword(s):  
Thin Film ◽  
Steady State ◽  
Analytical Solution ◽  
Pulse Duration ◽  
Pulsed Laser ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Surface Geometry ◽  
Melt Pool

Pulsed laser surface melting (pLSM) is a technique that offers an efficient and effective way to modify the geometry surfaces without any addition or removal of material. The resultant surface geometry plays a critical role in several applications. This paper presents a steady-state thin-film approximation of the melt pool created by pLSM and the resulting semi-analytical solution for the evolved surface geometry. These predictions of the semi-analytical solution are then compared with a validated numerical solution. The comparison demonstrates a good match with errors ranging from ~4% to ~25% across several pulse duration. Larger errors are observed at comparatively lower and higher pulse duration, and smaller errors are observed for intermediate pulse duration values. Overall, the thin film solution is a reasonable and useful approximation of the evolved surface geometry through the pLSM process, thus saving significant computational costs.

Influence of Surface Geometry on Melt Pool Flows and Shape in Pulsed Laser Surface Melting

2021 ◽  
Author(s):  
Utsavkumar Mistry ◽  
Madhu Vadali
Keyword(s):  
Surface Tension ◽  
Numerical Study ◽  
Pulsed Laser ◽  
Surface Displacement ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Initial Surface ◽  
Surface Geometry ◽  
Melt Pool

Abstract Pulsed Laser Surface Melting (pLSM) is a technique that offers an efficient way to modify the geometry surfaces without any addition or removal of material. In pLSM, an incident laser beam melts a small region on the surface and induces surface tension and viscosity-driven flows that modify the surface geometry. Initial surface geometry plays an important role in deciding the melt pool flows and shape as it governs the initial surface tension acting on the melt pool. In this paper, we present a systematic numerical study that captures the effects of initial geometries using a two-dimensional axisymmetric model. The results show that geometries with higher curvatures result in deeper melt pools and higher surface displacement because higher fluid velocities aid the convection heat transfer. Additionally, we define a modified capillary number (CaM) which elegantly captures these effects.

scholarly journals Fabrication of nano-sized grains by pulsed laser surface melting

2010 ◽  
Vol 43 (9) ◽  
pp. 095402 ◽  
Author(s):  
Chengtao Wang ◽  
Hong Zhou ◽  
Pengyu lin ◽  
Na Sun ◽  
Qingchen Guo ◽  
...  
Keyword(s):  
Pulsed Laser ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting

scholarly journals Study of Optical Properties of Surface Layers Produced by Laser Surface Melting and Laser Surface Nitriding of Titanium Alloy

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3112 ◽  
Author(s):  
Aleksander Lisiecki
Keyword(s):  
Titanium Alloy ◽  
Optical Properties ◽  
High Power ◽  
Thermal Conditions ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Surface Layers ◽  
Melt Pool ◽  
Titanium Alloy Ti6al4v

This study measured optical properties, such as specular, diffuse, and total reflection for 808 nm wavelength, characteristic for high power diode lasers radiation, from the surface of titanium alloy Ti6Al4V at delivery conditions, polished, and oxidized. Moreover, the optical properties of surface layers produced by high power direct diode laser (HPDDL) melting and nitriding were determined. Additionally, a methodology for determining the value of absorption for 808 nm wavelength of the HPDDL radiation on the surface of a melt pool during laser surface melting and nitriding of titanium alloy was proposed. The results show that the distinct differences in absorption affect the heat transfer, thermal conditions of laser heating and thereby the penetration depth during laser melting and nitriding of the titanium alloy.

Study of Melt Pool Geometry and Solidification Microstructure during Laser Surface Melting of Inconel 625 Alloy

Optik ◽  
2021 ◽  
pp. 167766
Author(s):  
Jitender K. Chaurasia ◽  
A N Jinoop ◽  
P Parthasarathy ◽  
C.P. Paul ◽  
K.S. Bindra ◽  
...  
Keyword(s):  
Surface Melting ◽  
Laser Surface ◽  
Solidification Microstructure ◽  
Laser Surface Melting ◽  
Inconel 625 ◽  
Melt Pool ◽  
Inconel 625 Alloy

Local Microstructure and Hardness Variation After Pulsed Laser Micromelting on S7 Tool Steel

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Justin D. Morrow ◽  
Frank E. Pfefferkorn
Keyword(s):  
Tool Steel ◽  
Surface Hardness ◽  
Pulsed Laser ◽  
Processing Parameters ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Microstructure And Properties ◽  
Surface Polishing ◽  
Diffusion Controlled

Laser surface melting is being increasingly used as a method of surface polishing steels and other alloys, but understanding the effect of this process on the microstructure and properties is still incomplete. This work experimentally explores several basic questions about how the surface microstructure and properties of S7 tool steel change during a pulsed laser micromelting (PLμM) process. Evaluations of the microstructure and hardness suggest that diffusion-controlled processes such as melt homogenization and surface back-tempering are relevant during rapid microscale laser melting and that the laser parameters and process planning contribute to determining the final surface hardness. The results also suggest that some influence can be exerted over the final hardness obtained from laser surface melting by changing the processing parameters.

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