Heat and Mass Transfer in the Process of EB Penetration


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The incident energy flux impinged on the free surface of liquid layer was considered to be balanced with the latent heat in evaporation and the heat in directional conduction but neglecting convective heat transfer due to a small Peclet number at the cavity base. The quasi-steady state model was developed in this study to analyze the effect of the energy density during the penetration process and an exponential expression for penetration velocity as a function of liquid-thickness and temperature was also derived. The penetration velocity versus energy density calculated by the present model showed good agreements with the experimental data for drilling copper, which the relative errors between the calculated and the experimental data are less than 15%. By the setup of non-uniform grids distribution in numerical method, this work had successfully predicted the variation of the penetration velocity with energy density distribution. The effects of the energy density on flow rate, thickness of liquid layer, base temperature of fusion zone had also been discussed in this study.



Materials Science Forum (Volumes 561-565)

Main Theme:

Edited by:

Young Won Chang, Nack J. Kim and Chong Soo Lee




J. E. Ho and C. Y. Ho, "Heat and Mass Transfer in the Process of EB Penetration", Materials Science Forum, Vols. 561-565, pp. 1987-1990, 2007

Online since:

October 2007




[1] A.V. Luikov, T. L. Perelman and S. I. Anisimov, Evaporation of a solid into vacuum, Int. J. Anisimov, Evaporation of a solid into vacuum, Int. J. Heat Mass Transfer 14, 177-184(1971).

DOI: https://doi.org/10.1016/0017-9310(71)90087-1

[2] C.J. Knight. Transient vaporization from a surface into vacuum, AIAAJ. 20, 950-954 (1982).

[3] I. Langmuir, The vapor pressure of metallic tungsten, Phys. Rev. 2, 329-342(1973).

[4] J. F. Ready, Effects due to absorption of laser radiation, J. Appl. Phys. 36, 462-468 (1965).

[5] M. von Allmen, Laser drilling velocity in metals, J. Appl. Phys. 47, 5460-5463 (1976).

[6] N. A. Ol'Shanskii, Movement of molten metal during electron beam welding, Svar. Proiz. 21, 12-14(1974).

[7] P. S. Wei, and C. Y. Ho, Beam focusing characteristics effect on energy reflection and absorption in a drilling or welding cavity of paraboloid of revolution, International Journal of Heat and Mass Transfer 41, 3299-3308 (1998).

DOI: https://doi.org/10.1016/s0017-9310(98)00036-2

[8] P. S. Wei, and J. Y. Ho, Energy considerations in high-energy beam drilling, Int. J. Heat Mass Transfer. Vol. 33, No. 10, pp.2207-2217, (1990).

DOI: https://doi.org/10.1016/0017-9310(90)90121-a

[9] P. S. Wei and L. R. Chiou, Molten metal flow around the base of a cavity during a high-energy beam penetrating process, J. Heat Transfer110, 918-923(1988).

DOI: https://doi.org/10.1115/1.3250593

[10] W. H. Giedt and P. S. Wei, Temperature and velocity distributions in the liquid flowing around the front of an electron beam welding cavity, Proc. 7 th Int. Heat Trans-fer Conf, Vol. 6, pp.403-407. Hemisphere, Washington, DC(1982).