The distinct transient geometry and material response of a deforming glass surface during CO2 laser heating are related to the temperature history and the thermal regimes resulting from different energy deposition and heating rates. The transient deformation is measured using a probing system based on the photo thermal deflection technique. The variation with temperature of the optical constants yields a variable reflection signal which ultimately decreases, corresponding to a permanent volume expansion. The transient deflection signal associated with the variable deformation results from the distinct physical mechanisms in three thermal regimes, i.e., the elastic behavior, the glass transition, and the viscous flow regimes.

Issue Section:
Heat Transfer in Manufacturing
Keywords:
Heat Transfer, Laser, Manufacturing, Measurement Techniques, Nonintrusive Diagnostics, Participating Media
Topics:
Glass, Heating, Lasers, Surface deformation, Transients (Dynamics), Deflection, Deformation, Signals, Temperature, Carbon dioxide lasers, Elasticity, Geometry, Glass transition, Heat transfer, Manufacturing, Reflection, Viscous flow
1.
Kuo
D.
,
Vierk
S. D.
,
Rauch
O.
, and
Polensky
D.
,
1997
, “
Laser zone texturing on glass and glass-ceramic substrates
,”
IEEE Transactions on Magnetics
, Vol.
33
, No.
1
, Pt. 2, pp.
94
–
99
.
2.
Miller, R., and Bhushan, B., 1996, “Alternative substrates for gigabit recording,” Data Storage, pp. 37–42.
3.
Olmstead
M. A.
, and
Amer
N. M.
, and
Kohn
S.
,
1983
, “
Photothermal displacement spectroscopy: An optical probe for solids and surfaces
,”
Appl. Phys. A
, Vol.
32
, pp.
141
–
154
.
4.
Palik, E. D., 1985, Handbook of Optical Constants of Solids, Academic Press, San Diego.
5.
Tam
A. C.
,
Brannon
J.
,
Baumgart
P.
, and
Pour
I. K.
,
1997
, “
Laser texturing of glass disk substrates
,”
IEEE Transactions on Magnetics
, Vol.
33
, No.
5
, Pt. 1, pp.
3181
–
3183
.
6.
Teng
E.
,
Goh
W.
, and
Eltoukhy
A.
,
1996
, “
Laser zone texture on the alternative substrate disks
,”
IEEE Transactions on Magnetics
, Vol.
32
, No.
5
, Pt. 1, pp.
3759
–
3761
.
7.
Scherer, G. W., 1986, Relaxation in glass and composites, John Wiley and Sons, New York.
8.
Varshneya, A. K., 1994, Fundamental of inorganic glasses, Academic Press, San Diego.
9.
Zimmerman
P.
, and
Welsch
E.
,
1994
, “
Modeling of signal detection by using the photothermal probe beam deflection technique
,”
Rev. Sci. Instrum.
, Vol.
65
, No.
1
, pp.
97
–
101
.
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