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Characterization Techniques of NiTi Shape Memory Alloys
Francisco M. Braz FernandesFrancisco M. Braz Fernandes0 1 2 3 4 5 6 7 8 9
0
100
200
300
400
500
600
75
80
85
90
95
100
105
110
115
120
Ste
ss (M
Pa)
Strain (%)
Ni-rich NiTidia=1mm GL=57.8mm; CycTest upto 5.112mm(@9%)A=0.5A(0.13V)2nd cycle
Ele
ctric
al R
esis
tivity
( μΩ
-cm
)
Strain, ε (%)
Strain, ε
Strain, ε
Stre
ss, σ
(MPa
)
Stre
ss, σ
Stre
ss, σ
Below Mf
Temperature, T
Critical stress for dislocation slip (A)
Super-elasticity
Shape memoryeffect
Shape memory effect versus superelasticity
Critica
l stre
ss fo
r stre
ss in
duce
d mar
tensit
e
Critical stress for dislocation slip (B)
Above Af
NiNi--TiTi SystemSystem
Ligasricas em Ti
Ligasricas em Ni
W. Tang, B. Sundman, R. Sandström, C. Qiu. Acta materialia 47 (1999) 3457-3468
Austenite(B2)
Cubic
Martensite(B19’)
Monoclinic
R-phase(R)
Rhombohedral
DilatometryElectrical Resistivity
Transformation Characteristics
Cooling
Heating
Cooling
Heating
Cooling
Heating
DSC
Base Material Heat Affected ZoneHeat Affected ZoneWeld BeadWeld Bead
2 Theta
Martensite
Austenite
Martensite
TwoTwo magnetronsmagnetrons (1(1--inch inch diameterdiameter)) with shutterswith shutters
Entrance window for the Entrance window for the incoming beamincoming beam
Exit window for the Exit window for the diffracted beamdiffracted beam
Substrates carrier with Substrates carrier with heaterheater and and bias voltagebias voltage Tube to the z drive Tube to the z drive
Window protection foilsWindow protection foils
SpecificationsSpecifications• 2 unbalanced magnetrons with variable ion flux and energy (gas pressure, biasvoltage)• substrate heater (deposition at various
temperatures / annealing up to 700oC) • additional 2 gas supplies and 1 viewport
60o rotation
start
1st scan
+
background
20 W Ti
-10o rotation
B2 ⎨110⎬
Ti2Ni
90o rotation
B2(110)
Ti2Ni
20 W Ti0 W Ti0 W Ti
40 W TiNi + co-sputtering
30 W Ti
no sputtering
targets NiTi 40 W + co-sputtering Ti
Ar 3.5 E-3 mbarTdep = 450oC
Real-time in-situ phase design of NiTi SMA
Sample 6
B2(200)
Ti2Ni(511) B2(110)
Ti2Ni(440)
0 20 40 60 80 100 120 140 160 1800
100
200
300
400
500
Time (min.)
Net A
rea
(arb
. uni
ts)
Net area: B2(110) : B2(200)
Δa0
: B2(110) : B2(200)
3.02
3.03
3.04
3.05
3.06
3.07
3.08
Lattice parameter, a
0 (Å)
InIn situsitu XRD XRD studystudy ofofrecrystallization recrystallization ofof NiTiNiTi
“Study of the textural evolution in Ti-rich NiTi using synchrotron radiation”.A.S. Paula, J.H.P.G. Canejo, K.K. Mahesh, R.J.C. Silva, F.M. Braz Fernandes, R.M.S. Martins, A.M.A. Cardoso, N. Schell. Nuclear Instruments & Methods Physics B 246 (2006) pp. 206-210
ElectricalElectrical resistivityresistivityduringduring tensiletensile testingtesting
0 2 4 6 8 10
0
100
200
300
400
500
600
Strain (%)
Stre
ss (M
Pa)
Nor
mal
ised
Res
ista
nce
1,0
1,2
1,4
1,6
1,8
2,0
2,2
(i) Identification step
0 2 4 6 8 10
0
100
200
300
400
500
600
Strain (%)
Stre
ss (M
Pa)
Nor
mal
ised
Res
ista
nce
1,0
1,2
1,4
1,6
1,8
2,0
2,2
(i) Identification step0 2 4 6 8 10
0
200
400
600
Stre
ss (M
Pa)
Strain (%)
Nor
mal
ised
Res
isita
nce
1.0
1.2
1.4
1.6
1.8
2.0
2.2
(i) Identification step
0 2 4 6 8 100
200
400
600
Strain (%)
Stre
ss (M
Pa)
Nor
mal
ised
Res
ista
nce
(iii) Eraser step
1.0
1.2
1.4
1.6
1.8
2.0
2.2
0 2 4 6 8 10
0
100
200
300
400
500
600
Stre
ss (M
Pa)
Strain (%)
(ii) 3 Sub-cycles followed by a complete cycle
“Micromemory effects involved during martensitic transformation in Ni-rich NiTi alloys”.K. Mahesh, F. M. Braz Fernandes, C. M. L. Santos. Materials Science Forum 514-516 (2006) pp. 1668-1672.
ElectricalElectrical resistivityresistivityduringduring tensiletensile testingtesting
0.1565
0.1570
0.1575
0.1580
0.1585
0.1590
0.1595
0.1600
0.1605
3765 3785 3805 3825 3845 3865 3885 3905
Time (sec)
Res
ista
nce
/ Str
ain
(a.u
.)
res(V)strain
0 1 2 3 4 5 6 7 8 90
100
200
300
400
500
600
75
80
85
90
95
100
105
110
115
120
Stes
s (M
Pa)
Strain (%)
Ni-rich NiTidia=1mm GL=57.8mm; CycTest upto 5.112mm(@9%)A=0.5A(0.13V)2nd cycle
Ele
ctric
al R
esis
tivity
(μΩ
-cm
)
0.1565
0.1570
0.1575
0.1580
0.1585
0.1590
0.1595
0.1600
0.1605
3765 3785 3805 3825 3845 3865 3885 3905
Time (sec)
Res
ista
nce
/ Str
ain
(a.u
.)
res(V)strain
InIn situsitu XRD / ERXRD / ER
25 26 27 28 29 30 31 32 33 34
100
1000
10000
4020
100
7055
-10
-30-40
-20
B19
'(1 1
1)
B19
'(0 0
2)
R(3
0 0
)B
2(1
1 0)
R(1
1 2
)
B19'
(1 1
1)
B19
'(0 2
0)
B19'
(1 0
1)
Dec
reas
ing T
empe
ratu
re (º
C)
2 Theta
Inte
nsity
(Log
Cou
nts)R
(1 0
2)
-50
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 701
10
100
1000
75
80
85
90
95
100
105
110
115
Inte
grat
ed A
rea
(log
scal
e)
Temperature (ºC)
(a) B2(1 1 0) R(1 1 2) R(3 0 0) R(1 0 2) Bulk ER
Bul
k E
R (μ
Ω-c
m)
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 7010
100
1000
75
80
85
90
95
100
105
110
115
B19'(1 0 1) B19'(0 2 0) B19'(1 1 1) B19'(0 0 2) B19'(1 1 1)
Inte
grat
ed A
rea
(log
scal
e)
Temperature (ºC)
(b)
Bulk ER
Bul
k E
R (μ
Ω-c
m)
Resistividade eléctrica / DRX in situ
R-phase
R-phaseR-phase
B2
B19’ B2
Heating
Cooling
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 701
10
100
1000
75
80
85
90
95
100
105
110
115
Inte
grat
ed A
rea
(log
scal
e)
Temperature (ºC)
(a) B2(1 1 0) R(1 1 2) R(3 0 0) R(1 0 2) Bulk ER
Bul
k E
R (μ
Ω-c
m)
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 7010
100
1000
75
80
85
90
95
100
105
110
115
B19'(1 0 1) B19'(0 2 0) B19'(1 1 1) B19'(0 0 2) B19'(1 1 1)
Inte
grat
ed A
rea
(log
scal
e)
Temperature (ºC)
(b)
Bulk ER
Bul
k E
R (μ
Ω-c
m)
“Simultaneous probing of phase transformations in Ni-Ti thin film Shape Memory Alloy by synchrotron radiation-based X-ray diffraction and Electrical Resistivity”. F.M. Braz Fernandes, K.K. Mahesh, R.M.S. Martins, R.J.C. Silva, C. Baehtz, J. von Borany. Materials Characterization 76 (2013) pp. 35-38
EndodonticEndodontic filesfiles
“Mechanism of NiTi file fracture based on rotation/flexion assays in threeendodontic files”. S. Vilaverde Correia, R. J. C. Silva, M.T. Nogueira, R. F. Martins, L. Pires Lopes, F.M. Braz Fernandes. Actas de “11ª Jornadas Portuguesas de Fractura / 11th Portuguese Conference on Fracture” (ISBN 978-989-95683-0-3), pp 383- 392, Caparica, 2008.
EndodonticEndodonticfilesfiles
EndodonticEndodontic filesfilesM
-Tw
o .
04(3
5)
ProFi
le.0
4(3
5)
InIn situsitu XRD XRD ofof thermomechanicalthermomechanical cyclingcycling
InIn situsitu XRD XRD ofof thermalthermal / / mechanicalmechanical
cyclingcyclingThermal cycling
Stress inducedprecipitation
Multilayer reaction
AcknowledgementsAcknowledgements
A. A. CavaleiroCavaleiro (CEMUC), (CEMUC), A.S. Paula (CENIMAT, now with A.S. Paula (CENIMAT, now with UniversidadeUniversidade Federal Federal FluminenseFluminense –– UFF)UFF),,C. C. BaetzBaetz (ROBL (ROBL –– ESRF; HZDR),ESRF; HZDR),F. F. NevesNeves (CENIMAT, now with LNEG),(CENIMAT, now with LNEG),J.P. Oliveira (CENIMAT),J.P. Oliveira (CENIMAT),K.K. Mahesh (CENIMAT, now with K.K. Mahesh (CENIMAT, now with Vivekananda College of Engineering & Technology)Vivekananda College of Engineering & Technology), , M.T. M.T. NogueiraNogueira (CENIMAT),(CENIMAT),M.T. VieiraM.T. Vieira (CEMUC),(CEMUC),N. Schell (P07N. Schell (P07--PETRA, HZG), PETRA, HZG), R.J.C. Silva (CENIMAT),R.J.C. Silva (CENIMAT),R.M. Miranda (UNIDEMI),R.M. Miranda (UNIDEMI),R.M.S. Martins (CENIMAT, ITN),R.M.S. Martins (CENIMAT, ITN),S. Ramos (CEMUC),S. Ramos (CEMUC),S.V. S.V. CorreiaCorreia (CENIMAT),(CENIMAT),
Master thesis completed
• Rui Miguel Santos Martins, “Produção de películas finas de ligas Ni-Ti com memória de forma para aplicações em dispositivos microelectromecânicos”, FCT/UNL, 29/07/2004. Supervisor: F. M. Braz Fernandes.• João Paulo Heitor Godinho Canejo, “Tratamento térmico de ligas de memória de forma visando a obtenção de diferentes gamas de temperaturas de transformação”, FCT/UNL, 06/04/2005. Supervisor : F. M. Braz Fernandes.• Daniel Silva, “Modelação numérica de compósitos inteligentes” . FCT/UNL, 24/07/2008. Supervisors: Rui Martins (DEMI, FCT/UNL) e F. M. Braz Fernandes.• Ricardo Nascimento, “Produção e Caracterização de Compósitos Inteligentes”, FCT/UNL, 20/03/2009. Supervisors: F. M. Braz Fernandes e A. Velhinho.• Cátia Gaspar, “Aplicações de ligas NiTi em Engenharia Civil”, Univ Católica e FCT/UNL. Supervisors: F. M. Braz Fernandes e Ionut Moldovan (Univ Católica).• Diana Cardoso Simão. Mestrado Integrado em Medicina Dentária (UL). Caracterização térmica de limas System Profile GT e de limas ProFile GT series X em estado novo. Mestrado Integrado em Medicina Dentária (FMD-UL). Supervision: Sancho Correia (FMD-UL), F.M. Braz Fernandes.• Francisca Neves Sena Alçada Ribeiro. Mestrado Integrado em Medicina Dentária (UL). Caracterização de limas profile system GT e profile GT series X por difracção de raios-X. Mestrado Integrado em Medicina Dentária (FMD-UL). Supervision: Sancho Correia (FMD-UL), F.M. Braz Fernandes.• Luis Alberty Vieira. Soldadura Laser de Ligas com memória de forma. Mestrado em Engª Mecânica, FCT/UNL. Supervisor: Rosa Miranda (DEMI). Co-supervisor: FM Braz Fernandes.• Magno Dinis Dias de Sousa. Caracterização do comportamento mecânico em rotação-flexão de limas ProSystemGT e Profile GT series X. Estudo comparativo in vitro. Mestrado Integrado em Medicina Dentária (FMD-UL). Supervision: Sancho Correia (FMD-UL), F.M. Braz Fernandes.• Luis Manuel Alberty Vieira (Eng.ª Mecânica, DEMI). “Soldadura laser de ligas com memória de forma”. Supervision: Rosa Miranda (DEMI), F. M. Braz Fernandes, 10/11/2010.• João Pedro Oliveira (Engª Materiais, DCM) “Correlation Between the Mechanical Cycling Behavior and Microstructure in Laser Welded Joints Using NiTi Shape Memory Alloys”, . Supervision: F. M. Braz Fernandes, Rosa Miranda (DEMI), 30/07/2012.• Alain Pereira (Engª Materiais, DCM) “Deformação plástica severa por ECAP de ligas com memória de forma”, Supervision: F. M. Braz Fernandes, K.K. Mahesh, 14/05/2013.
Advanced Training
PhD thesis completed :
• Andersan dos Santos Paula. “Tratamentos termomecânicos de ligas do sistema Ni-Ti. Caracterização estrutural e optimização das propriedades associadas ao efeito de memória de forma”. FCT/UNL, May 2006 (340 pp). Supervisor: F. M. Braz Fernandes.• Christian Mariani Lucas dos Santos, “Ligas Ni-Ti ricas em Ni: Tratamento Térmico, Termomecânico e Efeito de Micromemória de forma”, IME - Instituto Militar de Engenharia, 29/11/2006. Supervisors: Carlos Sérgio da Costa Viana (IME), F.M. Braz Fernandes.• Production and characterization of Cu-Al-Ni shape memory alloys. Carmela Gurau. UniversityGalati, Romania, 29/07/2008. Supervisors: E. Drugescu (Galati), F. M. Braz Fernandes. • Production and characterization of NiTi thin films. R.M.S. Martins. FCT/UNL, 17/10/2008. Supervisors: F. M. Braz Fernandes, Norbert Schell (DESY, Hamburg, Germany). • Comportamento em serviço de limas endodônticas de Ni-Ti. Sancho Vilaverde Correia. Scheduledfor September 2009. Faculdade de Medicina Dentária (Univ de Lisboa). Supervisors: F. M. Braz Fernandes, Luis Pires Lopes (FMDUL).
Advanced Training
•“Structural Characterisation of NiTi Thin Film Shape Memory Alloys”. Francisco M. Braz Fernandes, Rui Martins, M.ª Teresa Nogueira, Rui J. C. Silva, Patrícia Nunes, Daniel Costa, Isabel Ferreira, Rodrigo Martins. Sensors and Actuators, 99/1-2 (2002) pp. 55-58.•“In-situ GIXRD characterization of the crystallization of Ni-Ti sputtered thin films”. Rui M. S. Martins, Rui J. C. Silva, Francisco M. Braz Fernandes, Luis Pereira, Paulo R. Gordo, Manuel J. P. Maneira, Norbert Schell. Materials Science Forum 455-456 (2004) pp. 342-345.•“Real-time and in-situ structural design of functional NiTi SMA thin films”. N. Schell, R.M.S. Martins, F.M. Braz Fernandes. Applied Physics A - Materials Science & Processing, vol. 81, nr 7 (2005) pp. 1441-1445.•“Structural in-situ studies of Shape Memory Alloy (SMA) Ni-Ti thin films”. R.M.S. Martins, F.M. Braz Fernandes, R.J.C. Silva, M. Beckers, N. Schell. Nuclear Instruments & Methods Physics B 238 (2005) pp. 319-322.•“Optical Emission Spectroscopy study of magnetron assisted Ni-Ti dc sputtering”. Marcia Silva, F. M. Braz Fernandes, Paulo Gordo, Manuel Maneira. Materials Science Forum 514-516 (2006) pp. 1274-1278.•“In-situ observation of Ni-Ti thin film growth by synchrotron radiation scattering”. Rui M. S. Martins, F. M. Braz Fernandes, R. J. C. Silva, M. Beckers, N. Schell. Materials Science Forum 514-516 (2006) pp. 1588-1592.•“The influence of a poly-Si intermediate layer on the crystallization behaviour of Ni-Ti SMA magnetron sputtered thin films”. R.M.S. Martins, F.M. Braz Fernandes, R.J.C. Silva, L. Pereira, P.R. Gordo, M.J.P. Maneira, M. Beckers, A. Muecklich, and N. Schell. Applied Physics A - Materials Science & Processing 83 (2006) pp. 139-145.•“Growth of sputter-deposited Ni-Ti thin films: effects of a SiO2 buffer layer”. R.M.S Martins, N. Schell, M. Beckers, K.K. Mahesh, R.J.C. Silva, F.M. Braz Fernandes. Applied Physics A - Materials Science & Processing 84 (2006) pp. 285-289.•“In-situ study of Ni-Ti thin film growth on a TiN intermediate layer by x-ray diffraction”. R.M.S. Martins, N. Schell, R.J.C. Silva, L. Pereira, K.K. Mahesh, F.M. Braz Fernandes. Sensors and Actuators B: Chemical 126 (2007) pp. 332-337.•“Study of graded Ni-Ti Shape Memory Alloy film growth on Si(100) substrate”. R.M.S. Martins, A. Mücklich, H. Reuther, M. Beckers, N. Schell, R.J.C. Silva, L. Pereira, and F.M. Braz Fernandes. Applied Physics A - Materials Science & Processing 91(2008) pp. 291-299.•“Role of the substrate on the growth of Ni-Ti sputtered thin films”. R.M.S. Martins, N. Schell, M. Beckers, R.J.C. Silva, K.K. Mahesh, F.M. Braz Fernandes. Materials Science and Engineering A 481–482 (2008) pp. 626–629.•“Characterization of sputtered Shape Memory Alloy Ni-Ti films by cross-sectional TEM and SEM”. R. M.S. Martins, A. Mücklich, N. Schell, R.J.C. Silva, K.K. Mahesh, F.M. Braz Fernandes. Microscopy and Microanalysis 14 (2008) pp. 85-86.•“Development of sputtered Shape Memory Alloy (SMA) Ni–Ti films for actuation in ice cooled environments”. R.M.S. Martins, N. Schell, P.R. Gordo, M.J.P. Maneira, R.J.C. Silva, F.M. Braz Fernandes. Vacuum 83 (2009) pp. 1299-1302.•“Structural evolution of magnetron sputtered Shape Memory Alloy Ni-Ti films”, R.M.S. Martins, N. Schell, J.v. Borany, K.K. Mahesh, R.J.C. Silva, F.M. B. Fernandes. Vacuum 84 (2010) pp. 913-919.•“Texture development and phase transformation behaviour of sputtered Ni-Ti Films”. R.M.S. Martins, N. Schell, R.J.C. Silva, L. Pereira, K. K. Mahesh, F.M. Braz Fernandes. Journal of MaterialsEngineering and Performance 18 (2009) pp. 543-547.•“Texture development, microstructure and phase transformation characteristics of sputtered Ni-Ti Shape Memory Alloy films on TiN<111>”. Rui M.S. Martins, Norbert Schell, H. Reuther, L. Pereira, K. Mahesh, Rui Silva, F.M. Braz Fernandes. Thin Solid Films 519 (2010) pp. 122–128.•“Simultaneous probing of phase transformations in Ni-Ti thin film Shape Memory Alloy by synchrotron radiation-based X-ray diffraction and Electrical Resistivity”. F.M. Braz Fernandes, K.K. Mahesh, R.M.S. Martins, R.J.C. Silva, C. Baehtz, J. von Borany. Materials Characterization 76 (2013) pp. 35-38.
•Contacts:e-mail: [email protected]: http://bf.no.sapo.pt
Publications Ni-Ti thin films
•“Effect of thermal cycling on the transformation temperatures of a Ni-Ti shape memory alloy”. A.S. Paula, J.P.H.G. Canejo, Rui J. C. Silva, F.M. Braz Fernandes. Materials Science Forum 455-456 (2004) pp. 346-349.•“Effect of thermal cycling on the transformation temperature ranges of a Ni-Ti shape memory alloy”. A.S. Paula, J.P.H.G. Canejo, R.M.S. Martins, F.M. Braz Fernandes. Materials Science and Engineering A 378/1-2 (2004) pp. 92-96.•“In Situ High Temperature Texture Characterisation in NiTi Shape Memory Alloy Using Synchrotron Radiation”. A.S. Paula, K.K. Mahesh, F.M. Braz Fernandes, R.M.S. Martins, A.M.A. Cardoso, N. Schell. Materials Science Forum, 495-497 (2005) pp. 125-130.•“Structural Evolution on Thermal Cycling in Ti-Rich NiTi SMA”. A.S. Paula, J.P.H.G. Canejo, N. Schell, F.M. Braz Fernandes. Nuclear Instruments & Methods Physics Research B 238 (2005) pp. 111-114.•“Micromemory effects involved during martensitic transformation in Ni-rich NiTi alloys”. K. Mahesh, F. M. Braz Fernandes, C. M. L. Santos. Materials Science Forum 514-516 (2006) pp. 1668-1672.•“Study of the textural evolution in Ti-rich NiTi using synchrotron radiation”. A.S. Paula, J.H.P.G. Canejo, K.K. Mahesh, R.J.C. Silva, F.M. Braz Fernandes, R.M.S. Martins, A.M.A. Cardoso, N. Schell. Nuclear Instruments & Methods Physics B 246 (2006) pp. 206-210.•“One- and Two-Step Phase Transformation in Ti-rich NiTi Shape Memory Alloy”. A.S. Paula, K.K. Mahesh, C.M.L. dos Santos, J.P.H.G. Canejo, F.M. Braz Fernandes. International Journal of Applied Electromagneticsand Mechanics 23(1-2) (2006) pp. 25-32.•“X-ray Diffraction study of the phase transformations in NiTi shape memory alloy”. J. Uchil, F. M. Braz Fernandes, K. K. Mahesh. Materials Characterization 58(3) (2007) pp. 243-248.•“Electric resistance variation of NiTi SMA wires in thermomechanical tests: Experiments and simulation”. V. Novák, P. Šittner, G.N. Dayananda, F.M. Braz-Fernandes, K. K. Mahesh. Materials Science and EngineeringA 481–482 (2008) pp. 127–133.•“Thermomechanical behavior of Ti-rich NiTi shape memory alloys”. A.S. Paula, K.K. Mahesh, C.M.L. dos Santos, F.M. Braz Fernandes, C.S. da Costa Viana. Materials Science and Engineering A 481-482 (2008) pp. 146-150.•“Evolution of phase transformations after multiple steps of marforming in Ti-rich NiTi SMA”. A.S. Paula, K.K. Mahesh, F.M. Braz Fernandes. European Physical Journal 158 (2008) pp. 45–51.•“Mechanical behaviour of ausformed and marformed Ti-rich Ni-Ti shape memory alloys”. A.S. Paula, K.K. Mahesh, C.M.L. dos Santos, F.M. Braz Fernandes, C.S. da Costa Viana. Materials Science Forum 587-588 (2008) pp. 635-639.“Evolution of phase transformations after multiple steps of marforming in Ti-rich NiTi SMA”. A.S. Paula, K.K. Mahesh, F.M. Braz Fernandes. European Physical Journal 158 (2008) pp. 45–51.“The transformation behaviour of bulk nanostructured NiTi alloys”. F. Neves, F.M. Braz Fernandes, I. Martins, J.B. Correia, M. Oliveira, E. Gaffet, T.-Y. Wang, M. Lattemann, J. Suffner, H. Hahn. Smart Materials andStructures 18 (2009) 115003 (9pp).“XRD study of the transformation characteristics of severely plastic deformed Ni-Ti SMAs”. F.M. Braz Fernandes, K.K. Mahesh, R.J.C. Silva, C. Gurau, G. Gurau. Phisica Status Solidi 7 (2010) pp. 1348-1350.“Phase Transformation in Ni-Ti Shape Memory and Superelastic Alloys Subjected to High Pressure Torsion”. K.K. Mahesh, F.M. Braz Fernandes, G. Gurau. Advanced Materials Research 123-125 (2010) pp. 1007-1010.“Phase transformation and structural study on the severely plastic deformed NiTi alloys”. K.K. Mahesh, F.M. Braz Fernandes, R.J.C. Silva, G. Gurau. Physics Procedia, 10 (2010) pp. 22-27.“Structural Transitions in a Co2 Ni Ga Ferromagnetic Shape Memory Alloys”. C.M. Craciunescu, K.K. Mahesh, R.J.C. Silva, F.M. Braz Fernandes. Solid State Phenomena, 172-174 (2010) pp. 202-207.“Parametric Optimization of Ti-Ni Powder Mixtures Produced by Mechanical Alloying”. Filipe Neves, Franscisco M. Braz Fernandes, Isabel Martins, José Brito Correia. Journal of Alloys and Compound 509S (2011) S271–S274.“Mechanical behaviour of Nd:YAG laser welded superelastic NiTi”. L. Alberty Vieira, F.M. Braz Fernandes, R.M. Miranda, R.J.C. Silva, L. Quintino, A. Cuesta, J.L. Ocaña. Materials Science and Engineering A 528 (2011) pp. 5560-5565, doi:10.1016/j.msea.2011.03.089.“Stability in Phase Transformation After Multiple Steps of Marforming in Ti-Rich Ni-Ti Shape Memory Alloy”. A.S. Paula, K.K. Mahesh, F.M. Braz Fernandes. Journal of Materials Engineering and Performance 20 (2011) pp. 771-775. DOI: 10.1007/s11665-011-9920-5.“Structural study of extruded Cu Al13 Ni4 shape memory alloy”. F. M. Braz Fernandes, C.Gurau, K. K. Mahesh, R. J. C. Silva, G. Gurau. Metalurgia International 16 (2011) pp. 19-23.“Laser beam interaction with Ni–Mn–Ga ferromagnetic shape memory alloys”. C.M. Craciunescu, R.M.Miranda, R.J.C.Silva, E.Assunção, F.M.BrazFernandes Optics and Lasers in Engineering 49(2011) pp. 1289–1293.“Stability of thermal-induced phase transformations in the severely deformed equiatomic Ni–Ti alloys”. K. K. Mahesh, F. M. Braz Fernandes, G. Gurau. Journal of Materials Science 47-16(2012) pp. 6005-6014.“Role of oxygen and nitrogen in mechanical alloying mechanism of Ni–Ti powder mixtures”. F. Neves, F. M. Braz Fernandes, I. Martins and J. B. Correia. Powder Metallurgy 55-4(2012) pp. 268-272.“Effect of load cycling on the phase transformations in Ni–Ti wires for civil engineering applications”. M. Branco, L. Guerreiro, K.K. Mahesh, F.M. Braz Fernandes. Construction and Building Materials 36 (2012) pp. 508–519.“Graded transitions in Ni-Ti shape memory alloys processed by severe plastic deformation”. C. M. Craciunescu, F. M. Braz Fernandes. Functional Materials Letters vol 5 4(2012) 1250049 (4 pgs).“Analyzing mechanical properties and non-destructive characteristics of brazed joints of NiTi shape memory alloys to carbon steel rods”. T.G. Santos, F.M. Braz Fernandes, G. Bernardo, R.M. Miranda. InternationalJournal of Advanced Manufacturing Technology 66 (2013) pp. 787-793.
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