Sage Journals: Discover world-class research

Abstract

This paper elucidates the effects of different gases on the dominant mechanisms of the material ejection and removal and the cooling rate during laser percussion drilling. In particular, work was conducted for the reactive O₂ and inert Ar assist gases, in terms of their effects on (a) the behaviour and characteristics of spatter, (b) the recast layer characteristics and (c) the material ejection spark distribution for the drilling of Nimonic 263 alloy sheets using a Nd-doped yttrium aluminium garnet laser. It was shown that using O₂ assist gas, the material ejection was characterized with increased liquid particle ejection, coupled with volatile burning, possibly similar to that of nucleation-induced explosions, while the employment of Ar assist gas influenced the material ejection to be dominated by bulk radial liquid ejection.

Keywords

laser drilling spatter recast layer assist gas Nd:YAG laser material ejection

References

Patel

R. S.

Brewster

M. Q.

Gas-assisted laser-metal drilling: Experimental results. J. Thermophysics, 1991, 5(1), 26–31.

Allmen

Mv.

Blatter

Laser beam Interactions with Materials, 1994 (Springer-Verlag, Berlin).

Dabby

F. W.

Paek

U. C.

High-intensity laser induced vaporization and explosion of solid material. IEEE J. Quantum Electronics, 1972, QE-8(2), 106–111.

Yilbas

B. S.

Sami

Liquid ejection and possible nucleate boiling mechanisms in relation to the laser drilling process. J. Phys. D: Appl. Phys., 1997, 30, 1996–2005.

Wei

P. S.

Chiau

L. R.

Molten metal flow around the base of a cavity during a high-energy beam penetrating process. Int. J. Heat Transfer, 1988, 110, 918–923.

Yilbas

B. S.

Experimental study into ejected materials during laser-metal interaction at subatmospheric pressures of drilling ambients. Doga Turkish J. Engng Environmental Sci., 1988, 12(1), 68–73.

Heglin

L. M.

Laser drilling. In The Industrial Laser Annual Handbook (Eds Belforte

Levitt

), 1986, pp. 116–120 (Penn Well, Tulsa, Oklahoma).

Patel

R. S.

Brewster

M. Q.

Effect of oxidation and plume formation on low power Nd: YAG laser metal interaction. Trans. ASME, J. Heat Transfer, 1990, 112, 170–177.

Low

D. K. Y.

Corfe

A. G.

Effects of assist gas on the spatter physical characteristics during laser percussion drilling of NIMONIC 263 alloy. Appl. Surf. Sci., 2000, 154, 689–695.

10.

Low

D. K. Y.

Corfe

A. G.

Characteristics of spatter formation under the effects of different process parameters during laser drilling. In Proceedings of International AMPT 1999 Symposium on Manufacturing Processes, Dublin, 1999, Vol. 1, pp. 457–466 (Dublin City University, Dublin).

11.

Wallis

P. B.

Applications. In The Nimonic Alloys (Eds Betteridge

Heslop

), 1974 (J. W. Arrowsmith, Bristol).

12.

Brandes

E. A.

Brook

G. B.

(Eds) Smithells Metals Reference Book, 1992 (Butterworths-Heinemann, Oxford).

13.

Abott

D. H.

Albright

C. E.

CO₂ shielding gas effects in laser welding mild steel. J. Laser Applics, 1994, 6, 69–80.

14.

Allmen

M. V.

Laser drilling velocity in metals. J Appl. Phys., 1976, 47(12), 5460–5463.

15.

Ganesh

R. K.

Bowley

W. W.

Bellantone

R. R.

Hahn

A model for laser hole drilling in metals. J. Computational Phys., 1996, 125, 161–176.

16.

Easterling

Introduction to the Physical Metallurgy of Welding, 1983 (Butterworths-Heinemann, Oxford).

17.

Bauerle

Laser Processing and Chemistry, 1996 (Springer-Verlag, Berlin).

18.

Steen

W. M.

Laser Material Processing, 1998 (Springer-Verlag, London).

19.

Draper

C. W.

Poate

I. M.

Laser surface alloying. Int. Metal Rev., 1985, 30, 85.

20.

Chan

Mazumder

Chen

M. M.

A two-dimensional transient model for convection in a laser melted pool. Metall. Trans. A, 1984, 15(12), 2175–2184.

The influence of assist gas on the mechanism of material ejection and removal during laser percussion drilling

Abstract

Abstract

Keywords

References