The successful joining of dissimilar metal tubes would enable the selective use of the unique properties exhibited by biocompatible materials such as stainless steel and shape memory materials, such as NiTi, to locally tailor the properties of implantable medical devices. The lack of robust joining processes for the dissimilar metal pairs found within these devices, however, is an obstacle to their development and manufacture. Traditional joining methods suffer from weak joints due to the formation of brittle intermetallics or use filler materials that are unsuitable for use within the human body. This study investigates a new process, Laser Autogenous Brazing, that utilizes a thermal accumulation mechanism to form joints between dissimilar metals without filler materials. This process has been shown to produce robust joints between wire specimens but requires additional considerations when applied to tubular parts. The strength, composition, and microstructure of the resultant joints between NiTi and stainless steel are investigated and the effects of laser parameters on the thermal profile and joining mechanism are studied through experiments and numerical simulations.

References

References
1.
Sun
,
Z.
, and
Ion
,
J. C.
,
1995
, “
Review Laser welding of Dissimilar Metal Combinations
,”
J. Mater. Sci.
,
30
(
17
), pp.
4205
4214
.
2.
Springer
,
H.
,
Kostka
,
A.
,
Payton
,
E. J.
,
Raabe
,
D.
,
Kaysser-Pyzalla
,
A.
, and
Eggeler
,
G.
,
2011
, “
On the Formation and Growth of Intermetallic Phases During Interdiffusion Between Low-Carbon Steel and Aluminum Alloys
,”
Acta Mater.
,
59
(
4
), pp.
1586
1600
.
3.
Matsuoka
,
S.
, and
Imai
,
H.
,
2009
, “
Direct Welding of Different Metals Used Ultrasonic Vibration
,”
J. Mater. Process. Technol.
,
209
(
2
), pp.
954
960
.
4.
Watanabe
,
T.
,
Sakuyama
,
H.
, and
Yanagisawa
,
A.
,
2009
, “
Ultrasonic Welding Between Mild Steel Sheet and Al–Mg Alloy Sheet
,”
J. Mater. Process. Technol.
,
209
(
15–16
), pp.
5475
5480
.
5.
Ghosh
,
M.
, and
Chatterjee
,
S.
,
2002
, “
Characterization of Transition Joints of Commercially Pure Titanium to 304 Stainless Steel
,”
Mater. Charact.
,
48
(
5
), pp.
393
399
.
6.
Kundu
,
S.
, and
Chatterjee
,
S.
,
2008
, “
Characterization of Diffusion Bonded Joint Between Titanium and 304 Stainless Steel Using a Ni Interlayer
,”
Mater. Charact.
,
59
(
5
), pp.
631
637
.
7.
Campbell
,
C. E.
, and
Boettinger
,
W. J.
,
2000
, “
Transient Liquid-Phase Bonding in the Ni-Al-B System
,”
Metall. Mater. Trans. A
,
31
(
11
), pp.
2835
2847
.
8.
Vannod
,
J.
,
Bornert
,
M.
,
Bidaux
,
J.-E.
,
Bataillard
,
L.
,
Karimi
,
A.
,
Drezet
,
J.-M.
,
Rappaz
,
M.
, and
Hessler-Wyser
,
A.
,
2011
, “
Mechanical and Microstructural Integrity of Nickel–Titanium and Stainless Steel Laser Joined Wires
,”
Acta Mater.
,
59
(
17
), pp.
6538
6546
.
9.
Satoh
,
G.
, and
Yao
,
Y. L.
,
2011
, “
Laser Autogenous Brazing—A New Method for Joining Dissimilar Metals
,”
30th International Congress on the Applications of Lasers and Elecro-Optics
, Lake Buena Vista, FL, pp.
315
324
.http://www.columbia.edu/~yly1/PDFs3/602_2011.pdf
10.
Wagner
,
C.
,
1969
, “
The Evaluation of Data Obtained With Diffusion Couples of Binary Single-Phase and Multiphase Systems
,”
Acta Metall.
,
17
(
1
), pp.
99
107
.
11.
Bader
,
S.
,
Gust
,
W.
, and
Hieber
,
H.
,
1995
, “
Rapid Formation of Intermetallic Compounds by Interdiffusion in the Cu-Sn and Ni-Sn Systems
,”
Acta Metall. Mater.
,
43
(
1
), pp.
329
337
.
12.
Pharr
,
G. M.
,
Harding
,
D. S.
, and
Oliver
,
W. C.
,
1993
, “
Measurement of Fracture Toughness in Thin Films and Small Volumes Using Nanoindentation Methods
,”
Mechanical Properties and Deformation Behavior of Materials Having Ultra-Fine Microstructures
(NATO Science Series), Vol. 233,
M.
Nastasi
,
D. M.
Parkin
, and
H.
Gleiter
, eds.,
Springer
,
The Netherlands
, pp.
449
461
.
13.
Satoh
,
G.
,
Huang
,
X.
,
Ramirez
,
A. G.
, and
Lawrence Yao
,
Y.
,
2012
, “
Characterization and Prediction of Texture in Laser Annealed NiTi Shape Memory Thin Films
,”
ASME J. Manuf. Sci. Eng.
,
134
(
5
), p.
051006
.
14.
Raabe
,
D.
,
2000
, “
Scaling Monte Carlo Kinetics of the Potts Model Using Rate Theory
,”
Acta Mater.
,
48
(
7
), pp.
1617
1628
.
15.
Wei
,
X.
,
Yamaguchi
,
T.
, and
Knishio
,
K.
,
2011
, “
Formation of Intermetallic Compounds on the Bond Interface of Aluminum-Clad Copper and Its Influence on Bond Tensile Strength
,”
Appl. Mech. Mater.
,
117–119
, pp.
984
989
.
16.
Brandal
,
G.
,
Satoh
,
G.
,
Yao
,
Y. L.
, and
Naveed
,
S.
,
2013
, “
Beneficial Interface Geometry for Laser Joining of NiTi to Stainless Steel Wires
,”
ASME J. Manuf. Sci. Eng.
,
135
(
6
), p. 061006.
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