Abstract

This work defines a model to predict the characteristics of materials processed using reactive spray atomization and deposition. The materials considered are aluminum alloys while target dispersoids are primarily oxides. These may be obtained by the reaction of oxygen-containing atomization gas mixtures with molten alloy droplets. Droplet position and velocity histories are obtained from the numerical solution of the one-dimensional equation of motion. The energy equation inside the droplet is solved numerically using finite differences to predict the spatially resolved temperature field. The solid/liquid interface progression rate is estimated using a power law while an oxidation rate expression based on the Mott-Cabrera theory is used for the oxide thickness. Such a model should prove very valuable in determining the parameters controlling the volume fraction and the size distribution of the dispersoids for various systems. [S0022-1481(00)02901-7]

1.
Lavernia, E. J., and Wu, Y., 1996, “Spray Atomization and Deposition,” Wiley, New York.
2.
Dai
,
S. L.
,
Delplanque
,
J.-P.
, and
Lavernia
,
E. J.
,
1998
, “
Microstructural Characteristics of 5083 Al Alloys Processed by Reactive Spray Deposition for Net-Shape Manufacturing
,”
Metall. Mater. Trans. A
,
29A
, pp.
2597
2611
.
3.
Liu
,
H.
,
Rangel
,
R. H.
, and
Lavernia
,
E. J.
,
1994
, “
Modeling of Reactive Atomization and Deposition Processing of Ni3Al
,”
Acta Metall. Mater.
,
42
, No.
10
, pp.
3277
3289
.
4.
Kubaschewski, O., and Hopkins, B. E., 1953, “Oxidation of Metals and Alloys,” Butterworths, London.
5.
Hirth
,
J. P.
,
1978
, “
Nucleation, Undercooling and Homogeneous Structures in Rapidly Solidified Powders
,”
Metall. Trans. A
,
9A
, pp.
401
404
.
6.
Flemings, M. C., 1974, Solidification Processing, McGraw-Hill, New York.
7.
Lawrynowicz
,
D. E.
,
Li
,
B.
, and
Lavernia
,
E. J.
,
1997
, “
Particle Penetration During Spray Forming and Co-Injection of Ni3Al+B/Al2O3 Intermetallic Matric Composite
,”
Metall. Mater. Trans. B
,
28B
, No.
5
, pp.
877
897
.
8.
Mathur
,
P.
,
Applian
,
D.
, and
Lawley
,
A.
,
1989
, “
Analysis of the Spray Deposition Process
,”
Acta Metall. Mater.
,
37
, No.
2
, pp.
429
443
.
9.
Levi
,
C. G.
, and
Mehrabian
,
R.
,
1982
, “
Heat Flow During Rapid Solidification of Undercooled Metal Droplets
,”
Metall. Trans. A—Physical Metallurgy and Materials Science
,
13A
, No.
2
, pp.
221
234
.
10.
Ranz
,
W. E.
, and
Marshall
,
W. R.
,
1952
, “
Evaporation From Drops (Part I)
,”
Chem. Eng. Prog.
,
48
, No.
3
, pp.
141
180
.
11.
Grant
,
P. S.
,
Cantor
,
B.
, and
Katgerman
,
L.
,
1993
, “
Modelling of Droplet Dynamics and Thermal Histories During Spray Forming—I. Individual Droplet Behavior
,”
Acta Metall. Mater.
,
41
, No.
11
, pp.
3097
3108
.
12.
Thomas, L. H., 1949, “Elliptic Problems in Linear Difference Equations Over a Network,” Report, Watson Scientific Computing Laboratory, Columbia University, New York.
13.
Burden, R. L., and Faires, J. D., 1997, Numerical Analysis, Brooks/Cole, Pacific Grove, CA.
14.
Staniek, G., 1982, “Observation of Oxide Skin in Powder Metallurgy,” Technical Report, Air Force Wright Aeronautical Laboratory.
You do not currently have access to this content.