Dash, S. ; Tyagi, A. K. ; Baldev Raj, (2011) Melt pool vorticity in deep penetration laser material interaction Sadhana (Academy Proceedings in Engineering Sciences), 36 . pp. 251-265. ISSN 0256-2499
![]()
|
PDF
- Publisher Version
478kB |
Official URL: http://www.ias.ac.in/sadhana/Pdf2011Apr/251.pdf
Abstract
In the present study, the vorticity of melt motion in the keyhole and weld pool has been evaluated in case of high power CO2 laser beam welding. The circulation of vorticity is obtained as a function of Reynolds number for a given keyhole volume which is linked to Mach number variation. The shear stress and thermal fluxes present in the turbulent pool are linked to diffusivity and Prandtl number variation. It was shown that below a critical value of Rayleigh number, the conduction mode of melt transfer signifying beam absorption becomes dominant. Above this value, convective heat transfer indicates melting and evaporation occurring in the weld pool during laser welding. The evaporative recoil pressure expels the liquid while surface tension and hydrostatic pressure help to retain the melt in the keyhole cavity in this high power laser beam welding. The understanding of several hydrodynamic phenomena occuring in the weld pool is valuable not only for understanding basic mechanistic aspects but also for process optimization involved in laser beam welding.
Item Type: | Article |
---|---|
Source: | Copyright of this article belongs to Indian Academy of Sciences. |
Keywords: | Keyhole; Melt Pool; Vorticity; Dimensionless Numbers; Liquid-vapour Phase |
ID Code: | 91267 |
Deposited On: | 17 May 2012 10:30 |
Last Modified: | 19 May 2016 05:09 |
Repository Staff Only: item control page