Modeling of dynamic process in the laser-off period during laser drilling

Tingzhong Zhang; Xiaowu Ni; Jian Lu

doi:10.3788/COL201513.081403

Journals >Chinese Optics Letters >Volume 13 >Issue 8 >Page 081403 > Article

Chinese Optics Letters
Vol. 13, Issue 8, 081403 (2015)

Modeling of dynamic process in the laser-off period during laser drilling

Tingzhong Zhang^*, Xiaowu Ni, and Jian Lu^**

Author Affiliations

School of Science, Nanjing University of Science and Technology, Nanjing 210094, China

show less

DOI: 10.3788/COL201513.081403 Cite this Article Set citation alerts

Tingzhong Zhang, Xiaowu Ni, Jian Lu. Modeling of dynamic process in the laser-off period during laser drilling[J]. Chinese Optics Letters, 2015, 13(8): 081403 Copy Citation Text

EndNote(RIS)

BibTex

Plain Text

show less

Fig. 1. Scheme of numerical model.

Download full size | View in the Article

Fig. 2. (a) Numerical and (b) experimental comparisons of the keyhole shape with a laser energy of 4.86 J. The white bar represents 0.5 mm.

Download full size | View in the Article

Fig. 3. Image sequences of the keyhole fabricated by a single laser pulse with a laser energy of 4.86 J in both the laser-on and -off periods. The white bar represents 1 mm.

Download full size | View in the Article

Fig. 4. Temperature distributions of the keyhole fabricated by a single laser pulse with a laser energy of 4.86 J in both the laser-on and -off periods. The white bar represents 1 mm.

Download full size | View in the Article

Fig. 5. Velocity distributions of the keyhole fabricated by a single laser pulse with a laser energy of 4.86 J in both the laser-on and -off periods. The white bar represents 1 mm.

Download full size | View in the Article

Nomenclature (unit)	Symbol	Value
Melting/evaporation temperature (K)	$T_{m} / T_{v}$	933/793
Solid/liquid density ( $kg / m^{3}$ )	$ρ_{s} / ρ_{l}$	2702/2385
Solid/liquid specific heat (J/m/K)	$c_{s} / c_{l}$	917/1080
Solid/liquid conductivity (W/m/K)	$k_{s} / k_{l}$	237/100
Latent heat of fusion/evaporation (J/kg)	$L_{m} / L_{v}$	$3.6 \times 10^{5} / 1.09 \times 10^{7}$
Temperature coefficient of surface tension (N/m/K)	$\frac{\partial σ}{\partial T}$	$- 0.3 \times 10^{- 3}$
Dynamic viscosity (Pa s)	$μ$	$1.6 \times 10^{- 3}$
Convective heat transfer coefficient ( $W / m^{2} / K$ )	$h_{c}$	20
Radiation emissivity ( $W / m^{2} / K^{4}$ )	$ε$	0.2
Absorption coefficient	$η$	0.26
Stefan–Boltzmann constant ( $W / m^{2} / K^{4}$ )	$σ_{s}$	$5.67 \times 10^{8}$
Focal radius (μm)/Pulse width (μs)	$r_{0} / τ$	300/1000

Table 1. Properties of Aluminum and Constants in Simulation.[22,23]

View in the Article

Energy (J)	Depth^a (mm)	Depth^b (mm)	Diameter^a (mm)	Diameter^b (mm)
1.22	0.894	0.902	0.518	0.523
2.07	1.322	1.313	0.752	0.741
3.13	1.448	1.420	0.824	0.817
4.86	1.523	1.510	0.872	0.870
6.31	2.070	2.109	0.863	0.875
8.01	2.745	2.693	0.901	0.920
10.20	3.120	3.131	0.943	0.958
13.27	3.439	3.357	1.052	1.046

Table 2. Numerical and Experimental Data for Both Keyhole Depth and Width.

Tingzhong Zhang, Xiaowu Ni, Jian Lu. Modeling of dynamic process in the laser-off period during laser drilling[J]. Chinese Optics Letters, 2015, 13(8): 081403

Download Citation

EndNote(RIS)

BibTex

Plain Text

Set citation alerts for the article

Tools

Set citation alerts for the article

Save the article for my favorites

Paper Information