Energy redistribution during CO2 laser cladding

Abstract

This article examines the factors that effect the efficiency of the CO2-laser powder cladding process. By theoretical calculation and experimental work it has been possible to identify how much of the original laser energy contributes to the cladding process and how much is lost to the surrounding environment by reflection, radiation, convection, etc. Every aspect of energy redistribution has been analyzed and quantified and this has led to a deeper understanding of the process. The article concludes with a number of suggestions for improving the efficiency of blown powder laser cladding.

Numerical simulation of heat transfer and fluid flow in coaxial laser cladding process for direct metal deposition

“…A comparable experimental result was reported in Ref. 22 where 11% of the total CO 2 laser beam was found to be reflected and absorbed by a lateral-injected steel powder stream. The temperature and the liquid fraction distribution of the powder flow at 6 g / min after traveling 7 mm at the speed of 1 m / s ͑Ref.…”

Residual Stress Generation during Laser Cladding of Steel with a Particulate Metal Matrix Composite

“…The percentage of the incident laser power absorbed by the substrate p as , was taken as 30 %, based on published values for the energy distribution of CO 2 laser beams. [18] The proportion of total power reflected by powder and substrate was thus taken to be about 60 %. [18] Other thermal boundary conditions ) to an environment at 25°C.…”

“…[18] The proportion of total power reflected by powder and substrate was thus taken to be about 60 %. [18] Other thermal boundary conditions ) to an environment at 25°C. Build-up of the cladding was modeled using a volume element activation technique.…”

Solute transport and composition profile during direct metal deposition with coaxial powder injection

“…Qi et al [2] considered the coaxial laser powder interaction while modelling heat transfer and fluid flow during DMD. A semiempirical method of evaluating the laser energy redistribution during CO 2 laser cladding with lateral powder injection was reported by Gedda et al [5]. It was found that 50% of the laser power was reflected off the cladding melt, 10% was reflected off the powder cloud, 30% was used to heat the substrate, and 10% was used to melt the clad layer.…”

“…Attenuation of laser power during interaction between a laser and powder was investigated a lot [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Qi et al [2] considered the coaxial laser powder interaction while modelling heat transfer and fluid flow during DMD.…”