This paper presents the investigation of the macrostructure, microstructure, and solidification structure of a 316L/15% nickel coated TiC metal matrix composite produced by the laser engineered net shaping (LENS) process. The focus of this work was to (1) identify the solidification structure and to estimate growth/cooling rates at the solid/liquid interface, (2) identify and quantify discontinuities in the build structure, and (3) examine the effect of solidification and thermal history on the sample microstructure to further the understanding of the LENS process. A Numerical method was also developed to examine the influence of material type and LENS™ process parameters on the forming of the specific microstructures from thermodynamics and fluid dynamics point of view. Samples of 316L stainless steel were examined, microstructures of samples were used to estimate the corresponding cooling rate, and the cooling rate was compared with the results of numerical modeling. The computational results show reasonable agreement with experimentally determined cooling rate.

References

References
1.
Gu
,
D. D.
,
Meiners
,
W.
,
Wissenbach
,
K.
, and
Poprawe
,
R.
,
2012
, “
Laser Additive Manufacturing of Metallic Components: Materials, Processes and Mechanisms
,”
Int. Mater. Rev.
,
57
(
3
), pp.
133
164
.10.1179/1743280411Y.0000000014
2.
Keicher
,
D. M.
,
Romero
,
J. A.
,
Atwood
,
C. L.
,
Smugeresky
,
J. E.
,
Griffith
,
M. L.
,
Jeantette
,
F. P.
,
Harwell
,
L. D.
, and
Greene
,
D. L.
,
1996
, “
Free Form Fabrication Using the Laser Engineered Net Shaping (LENS™) Process
,”
Proceeding of Rapid Prototyping and Manufacturing ‘96, Dearborn, MI, published by the Society of Manufacturing Engineers
,
Dearborn, MI
, June 16–21.
3.
Smugeresky
,
J. E.
,
Keicher
,
D. M.
,
Romero
,
J. A.
,
Griffith
,
M. L.
, and
Harwell
,
L. D.
,
1997
, “
Laser Engineered Net Shaping (LENS™) Process: Optimization of Surface Finish and Microstructural Properties
,”
International Conference and Exhibition on Powder Metallurgy and Particulate Materials
, Chicago, IL, June 29–July 2, pp.
33
42
.
4.
Hofmeister
,
W.
,
Wert
,
M.
,
Smugeresky
,
J.
,
Philliber
,
J. A.
,
Griffith
,
M.
, and
Ensz
,
M.
,
1999
, “
Investigating Solidification With the Laser-Engineered Net Shaping (LENS™) Process
,”
JOM-e
,
51
(
7
).
5.
Wei
,
W.
,
Zhou
,
Y.
,
Ye
,
R. Q.
,
Lee
,
D.
,
Craig
,
J. E.
,
Smugeresky
,
J. E.
, and
Lavernia
,
E. J.
,
2002
, “
Investigation of the Thermal Behavior During the LENS™ Process
,”
International Conference on Metal Powder Deposition for Rapid Manufacturing
,
San Antonio, TX
, April 8–10.
6.
Zhang
,
Y.
,
Xi
,
M.
,
Gao
,
S.
, and
Shi
,
L.
,
2003
, “
Characterization of Laser Direct Deposited Metallic Parts
,”
J. Mater. Process. Technol
.,”
142
(
2
), pp.
582
585
.10.1016/S0924-0136(03)00663-0
7.
Elmer
,
J. W.
,
Allen
,
S. M.
, and
Eager
,
T. W.
,
1989
, “
Microstructural Development During Solidification of Stainless Steel Alloys
,”
Metall. Trans. A
,
20
(
10
), pp.
2117
2131
.10.1007/BF02650298
8.
Griffith
,
M. L.
,
Lane
,
H. D.
,
Romero
,
T. J.
,
Schlienger
,
E.
,
Atwood
,
C. L.
, and
Smugeresky
,
J. E.
,
1997
, “
Multi-Material Processing by LENS™
,” Proc. of the Solid Freeform Fabrication Symposium, Austin, TX, Aug. 11–13, pp.
387
394
.
9.
Zheng
,
B.
,
Smugeresky
,
J. E.
,
Zhou
,
Y.
,
Baker
,
D.
, and
Lavernia
,
E. J.
,
2008
, “
Microstructure and Properties of Laser-Deposited Ti6Al4V Metal Matrix Composites Using Ni-Coated Powder
,”
Metall. Mater. Trans. A
,
39
(
5
), pp.
1196
1205
.10.1007/s11661-008-9498-1
10.
Zheng
,
B.
,
Topping
,
T.
,
Smugeresky
,
J. E.
,
Zhou
,
Y.
,
Biswas
,
A.
,
Baker
,
D.
, and
Lavernia
,
E. J.
, “
The Influence of Ni-Coated TiC on Laser-Deposited IN625 Metal Matrix Composites
,”
Metall. Mater. Trans. A
,
41
(
3
), pp.
568
573
.10.1007/s11661-009-0126-5
11.
Abou-Ellail
,
M. M.
,
Gosman
,
A. D.
,
Lockwood
,
F. C.
, and
Megahed
,
I. E. A.
,
1978
, “
Description and Validation of a Three-Dimensional Procedure for Combustion Chamber Flows
,”
J. Energy
,
2
(3), pp.
71
80
.10.2514/3.62365
12.
Tong
,
T. W.
,
Abou-Ellail
,
M. M.
,
Li
,
Y.
, and
Beshay
,
K. R.
,
2004
, “
Numerical Computation of Reacting Flow in Porous Burners With an Extended CH4—Air Reaction Mechanism
,”
Proceedings of HTFED04, 2004 ASME Heat Transfer/Fluids Engineering Summer Conference
, Charlotte, NC, July 11–15, Paper No. HT-FED 2004-56012.
13.
Griffith
,
M. L.
,
Ensz
,
M. T.
,
Puskar
,
J. D.
,
Robino
,
C. V.
,
Brooks
,
J. A.
,
Philliber
,
J. A.
,
Smugeresky
,
E.
, and
Hofmeister
,
W. H.
,
2000
, “
Understanding the Microstructure and Properties of Components Fabricated by LENS
,” Sandia National Laboratories, Report No. SAND2000-1000C.
14.
Katayama
,
S.
, and
Matsunawa
,
A.
,
1998
, “
Formation Mechanism and Prevention of Defects in Laser Welding of Aluminum Alloys
,”
Proceedings of CISFFEL 6
, Vol.
1
, Toulon, France, June 15–19, pp.
215
222
.
15.
Fridlender
,
B. A.
,
Neshpor
,
V. S.
,
Ermakov
,
B. G.
, and
Sokolov
,
V. V.
,
1973
, “
Thermal Diffusivity and Conductivity of Pyrolytic Titanium Carbide, Columbium Carbide, and Titanium Nitride at High Temperatures
,”
J. Eng. Phys.
,
24
(
2
), pp.
210
212
.10.1007/BF00828868
16.
Brooks
,
J. A.
, and
Lippold
,
J. C.
,
1993
, “
Selection of Wrought Austenitic Stainless Steels
,”
ASM Handbook Vol. 6: Welding, Brazing and Soldering
,
American Society for Metals
,
Metals Park, OH
, pp.
457
465
.
17.
Kou
,
S.
,
NetLibrary, Inc.
,
2003
,
Welding Metallurgy
,
Wiley-Interscience
,
Hoboken, NJ
.
18.
Zheng
,
B.
,
Zhou
,
Y.
,
Smugeresky
,
J. E.
,
Schoenung
,
J. M.
, and
Lavernia
,
E. J.
,
2008
, “
Thermal Behavior and Microstructure Evolution During Laser Deposition With Laser-Engineered Net Shaping: Part II. Experimental Investigation and Discussion
,”
Metall. Mater. Trans. A
,
39
(
9
), pp.
2237
2245
.10.1007/s11661-008-9566-6
You do not currently have access to this content.