LTuA5 Laser-assisted micro- and nanotechnologies IV ICONO/LAT 2010, Kazan, Russia, August 23-26 1...

LTuA5 • Laser-assisted micro- and nanotechnologies IV

ICONO/LAT 2010, Kazan, Russia, August 23-26

1

SLS and electrophysical properties of

multilayer polymer structures with Ni-Cu

nano additives.I. Shishkovsky1, Yu. Morozov2.

2) Institute of Structural Macrokinetics and Materials Science , Russian Academy of Sciences ;

1) P.N. Lebedev Physics Institute /LPI/, Samara branch, Russian Academy of Sciences ;



2

Outlines of presentation:1. What is Rapid Prototyping & Manufacturing? 2. Why is polycarbonate with Cu and/or Ni nano additives ? RP

roadmap, FP7 and MEMS-NEMS fabrication…3. Description of initial nano powders. 4. Selective laser sintering of separate monolayers from powder

compositions: PC + nano Ni, PC + nano Cu; Compare with micro Cu…

5. Selective Laser Sintering of three dimensional parts from powder compositions: PC + nano Ni, PC + nano Cu;

6. Scanning Electron Microcopy with Element Dispersive X-ray Analysis of sintered porous samples;

7. Qualitative X –ray analysis of sintered porous samples; 8. Temperature dependencies of electrophysical properties of

laser synthesized nano compositions;9. Functional graded structures and 3D parts fabrication via

SLS method from powder nano compositions with interleaving nickel – PC – copper;

10.Conclusions.



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What is Rapid Prototyping & Manufacturing?

Combination of Computer Aid Design /CAD/ approach, which realized in the professional packages ( - AUTOCAD, CATIA, Pro - Engineer, 3D Studio, Solid Work and etc.) with new high-technology of synthesis 3D part and tools named as-Rapid Prototyping & Manufacturing, Solid Free Form Fabrication )

The goal of Rapid Prototyping (Selective Laser Sintering is one from scope technique of RP) is to be able to quickly fabricate complex-shaped, three dimensional

parts directly from powder compositions base on CAD models.

Introduction



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Why is polycarbonate with Cu and/or Ni nano additives

2. Petrov A.L., Scherbakov V.I., Shishkovsky I.V. Method of

laser synthesis of volume gradient articles. Application № 2000120948/20, priority from 11.08.2000. Patent of RF № 2212982 log in 27.09.2003 г.

3. Zubriaeva N/I/ and etc. Method of manufacturing of oxide catalysts. Application № 99127936/04, priority from 30.12.1999. Patent of RF № 2188709 log in 10.09.2002 г.

crystalline hydrate nickel nitrate Ni(NO3)26H2O

1. Kuprianov N.L., Petrov A.L., Shishkovsky I.V. Conditions of selective laser sintering by circuit of metal-polymer powder compositions. //Russian Journal –Fizika I himia obrabotki materialov.- 1995.- № 3. - p. 88-93.

Shishkovsky I.V., Kuprianov N.L. Method of manufacturing of volume articles

from powder compositions. Application 95110182/ 02 (017874) priority from 16.06.96, 10. Patent of RF № 2145269 log in 10.02.2000 г.

Background of problem



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«Roadmap» MEMS-NEMS in frameworks of FP7

«Top-Down» and «Bottom-Up» approaches convergence in

nanotechnology

MEMS-Micro-Electro-Mechanical Systems; NEMS – Nano-Electro-Mechanical Systems – sensors, implants, filter, pumps, delivery systems, actuators ant etc.

Background of problem



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Initial powder materials

The nickel and copper nanoparticles were prepared at the ISMMS of RAS by means of the levitation jet technique .

The mean size values of thus prepared Ni particles were 27.8, 32.2, 119, and 184 nm. The Ni percentage and specific surface area of the powders were 86.6/ 25.1; 11.2/ 26.9; 94.2/ 5.73; and 98.3 at. %/ 3.68 m2/g, respectively (the rest of the mass was NiO). The mean size values of Cu particles were (1.- 76-100; 2.- 90-120) nm. The Ni percentage and specific surface area of the powders were measured (1. – 96.8/3.4; 2. – 98.2/2.7) w.% Cu (bal., CuO) / m2/g, respectively.

A thermostable polycarbonate (PC) powder was used as the binder. A commercially available PC powder (LET-7 grade, Russia) had the particles size of 20-40 m. The starting Ni + PC blend powders were prepared in the weight ratios 1:1 or 1:2 and Cu + PC = 1:9, 1:4, 3:7. In the case of copper, similar powder compositions were mixed with use of micro size Cu (~ 50mm) for comparison of sintering results.



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Initial nano particles of nickel and copper

Scan electron microscopy of initial particles: a) - Ni (mean particle size 26–32 nm) ; b) - Cu (mean particle size 70-96 nm) .

b)a)



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SLS regime optimization for metal-polymer powder composition РС + Cu =

3:7, Р = 11, 8.6, 6.2 W (monolayer approach, square 10x10 mm)

Cu particle size – 50 m Cu particle size – 70 nm

0 10 20 30 40

V, (m m /s)0.4

0.8

1.2

1.6

2

2.4

2.8 h, (m m )

1

2

3

0 100 200 300 400 500

V, (m m /s)-0.4

0

0.4

0.8

1.2

1.6

2 h, (m m )

1

23



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Monolayer SLS in powder compositions: РС + copper

Cu particle size – 50 m Cu particle size – 70 nm

Р= 8.7 W V=40 mm/s

Cu + PC=1:4 Р=8,7 W; V=40 mm/s,

Cu + PC=3:7 Р=6,2 W; V=80 mm/s,

Cu + PC=3:7 Р=8,7 W; V=80 mm/s;

Cu + PC=1:9



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Three – dimensional layer – by - layer SLS of porous samples from powder compositions РС + Cu, square 10x10

mmCu particle size – 50 m

Cu particle size – 70 nm

P = 8,7 W, V = 80 mm/s, Cu + PC = 1:9

P = 8,7 W, V = 160 mm/s, Cu + PC = 1:4

P = 6,2 W, V = 80 mm/s, Cu + PC = 3:7

Р = 6,2 W, V = 13,3 mm/s

Cu + PC = 1:9 Р = 8,7 W , V = 40 mm/s

Cu + PC = 1:4 Р = 6,2 W, V = 13,3 mm/s

Cu + PC = 3:7

Laser-assisted micro- and nanotechnologies

LTuM19 • ICONO/LAT 2010, Kazan, Russia, August 23-26

11

Polycarbonate destruction during SLS of metal –polymer powder compositions

Density - (left) and intrinsic viscosity - (right) of 3D sintered parts dependence vs. laser scan velocity– V.

Curves 1,3 – Laser powder Р = 2.1 W; 2,4 –

Р = 2.9 W. Powder mixture PC + Cu = 9:1.



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Polycarbonate destruction during SLS of metal – polymer powder composition

Logarithm dependence of sol-gel fraction S% (left, curves 1-5) and degree of cross-linked

polymer J (right, curves 6-10) vs. laser

scan velocity – V. Laser power 1,7 – Р = 2.1 W;

2,6 – Р = 2.9 W; 3-5 and 8-10 -- Р = 0.7 W. Curves 3,8 – polymer

level – 9.1%; 4,9 – 14%; 5,10 – 20 % from

common mass of powder mixture.



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Curves (4-6) of TG analysis– sample mass changing W% (Y axis - left) and curves (1-3) of DTG analysis – W/W0 % (Y axis - right) under different heating velocities Vh in air medium (- а) and nitrogen (- b) vs temperature changing. Powder composition

PC + Cu = 9:1. Firm line- Vh = 20; stroke-dotted – 10; dashed-line - 5 0C/min.

TGA and DTA of 3D samples after SLS on air



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Curves (4-6) of TG analysis– sample mass changing W% (Y axis - left) and curves (1-3) of DTG analysis – W/W0 % (Y axis - right) under different heating velocities Vh in air medium

(- а) and nitrogen (- b) vs temperature changing. Powder composition PC + Cu = 9:1. Firm line- Vh = 20; stroke-dotted – 10; dashed-line - 5 0C/min.

TGA and DTA of 3D samples after SLS on nitrogen



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Kinetic constants of PC in MPC of different content, determined by Kissinger method

Energy activation Е, кJ/mol

Preexponential factor А, s-1

PC content in MPC, %

w. air nitrogen air nitrogen 20,0 31,8 95,9 7,6·105 2,8·106 14,3 85,4 138,4 7,2·105 1,5·109 9,1 113,3 138,4 1,2·107 1,5·109

Ln (F/TM2) = Ln (n·R·A·Wm

n-1/E) = E/(R·TM), Where F – velocity of sample heating under TGA; Tm – temperature of maximum velocity mass loss (DTA dates); E – energy activation; n – order of reaction; A – preexponential factor; Wm – sample mass under moment of maximum loss .



16

Time-of-flight mass spectroscopy of secondary ions TOF-SIMS of samples after SLS in powder mixture

nano Ni – PC 1 : 1 : low atom mass.



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Time-of-flight mass spectroscopy of secondary ions TOF-SIMS of samples after SLS in powder mixture nano Ni – PC 1 : 1 :

high atom mass.

Fingerprint Ions of Polycarbonate



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Three – dimensional layer – by - layer SLS of porous samples from powder compositions РС + Ni = 2:1, square

10x10 mmP = 6 W, V = 36.7 cm/s

Over a magnetic field Without magnetic field



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Scanning electron microscope investigation of laser sintered samples

from powder mixture Ni–PC (1 : 1): Р = 6 W, v = 17.4 cm/s

Element Atomic %

S1 S2 S3

C K 55.78 97.36 55.15

O K -- -- 6.50

Ni K 44.22 2.64 38.35



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Scanning electron microscope investigation of laser sintered samples

from powder mixture Ni–PC (1 : 2) : P = 6 W, v = 17.4 cm/s under high magnification.

Element Atomic%

S1 S2 S3

C K 71.89 80.66 83.82

O K 3.42 19.18 4.24

Ni K 24.69 0.16 11.95



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XRD patterns of laser sintered samples from Ni – PC mixtures : 1 : 1 (1) and 1 : 2 (2); P = 6 W, v = 17.4 cm/s. Curve (3) –

PC with nano additives Cu and Ni.



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Scanning electron microscope study of laser sintered samples from powder

mixture Cu–PC (3 : 7): Р = 8.7 W, v = 10 cm/s

Cu particle size – 50 m

Cu particle size – 70 nm



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XRD patterns in PC + Cu system: a) pure PC without LI; b) XRD patterns in PC + Cu system: a) pure PC without LI; b) PC + nano Cu = 3:7 without LI; c-e) PC + micro Cu; f-h) PC PC + nano Cu = 3:7 without LI; c-e) PC + micro Cu; f-h) PC

+ nano Cu. + nano Cu. c) c) PP = 6.2 W, = 6.2 W, vv = 13.3 cm/s, PC + Cu = 1:9; d) 11/20/1:4; e) = 13.3 cm/s, PC + Cu = 1:9; d) 11/20/1:4; e)

6.2/20/3:7; f) 11/20/1:4; g) 8.7/160/1:4; h) 6.2 W/80cm*s6.2/20/3:7; f) 11/20/1:4; g) 8.7/160/1:4; h) 6.2 W/80cm*s--

11/3:7, respectively./3:7, respectively.



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Temperature dependencies of real part of dielectric permeability and a loss tangent in laser synthesized nano composition base on Cu + PC = 1:9: 1) black circles are heating stage; 2) white

circles are cooling.

Temperature measurements was conducted under 1 MHz frequency at exhibit of the constant voltage displacement 40 V, in thermostats within the temperatures range 300-400 K,

by means of digital instrument LRC E7-12 (Russia).

Р=6,2 W; V=40 mm/s

2 0 4 0 6 0 8 0

T, (Ñ)0.63

0.64

0.65

0.66

0.67

2 0 4 0 6 0 8 0

T , ( C )0 . 0 4

0 . 0 6

0 . 0 8

0 . 1 tg()



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Functional graded structures and 3D parts fabrication via SLS method from powder nano compositions with

interleaving nickel – PC – copper, 10x10 mm

Earlier* it has been found that giant magnetoresistance of the multilayers is strongly dependent on the relative amount of nickel and cobalt present in the ferromagnetic layer. Magnetoresistance is also strongly dependent on the thickness of both ferromagnetic and non-magnetic layers and increase linearly with increasing number of interfaces. SLS process allows to create such interleaving ferromagnetic (Ni, Fe) and non-magnetic (Cu, PC) layers via natural course.

Ni + PC = 1:2 – 5 layers,then Cu + PC = 1:4 - 5 layers

Cu + PC = 1:4, then Ni + PC = 1:2 – alternation per layer.

Ni + PC = 1:2 – 3 layers,then Cu + PC = 1:9 – 3 layers



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SEM and EDX analysis after SLS of nano FG structures: Cu + PC – nano Ni + PC

(lateral surface view)

Red - NiBlue - CGreen - Cu

polycarbonate



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Conclusion

1. It was shown a principle possibility of SLS of metal-polymer powder compositions with nano additives Ni and/or

Cu,, which ensures nano particle sizes conservation.

3. The optimal regimes of laser influence were determined as for single monolayers as layer - by - layer SLS process.

2. It was shown a principle possibility of functional graded three - dimensional parts fabrication via the interleaving of

the metal - polymer powdered compositions with Ni and/or Cu additives, which ensures nano particle sizes

conservation.

4. SEM with EDX analysis and X-ray qualitative analysis of laser sintered microstructures were shown, that practically an initial particle size was kept. This is important for catalyst applications.

5. Temperature dependence of the dielectric permeability and the loss tangent in PC – Cu nanocomposite was studied. Hysteresis phenomena were observed in the laser synthesized samples that can be useful for MEMS-NEMS applications.

7. Our technique can be extended for the encapsulation of aluminium, iron, titanium, and/or cobalt nanoparticls.

6. The sol-gel fraction content is indicated, that complete destruction PC under laser influence is not observed. It was optimized PC content in metal-polymer mixture. The comparison of our measurements with original values by the intrinsic viscosity and the molecular weight PK confirms this conclusion. Activation nature of thermo-oxidation destruction substantially decreases with an increase of the PC content, but comparison by the absolute values shows that the thermal degradation plays the predominant role during SLS process. Static TOF-SIMS spectra revealed the formation of new structures during the SLS process.



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Thank you for the attention.

Contact address: Prof. Igor V. Shishkovsky, Laboratory of Technological Lasers, P. N. Lebedev Physical Institute (LPI) of Russian Academy of Science (Samara branch).Novo-Sadovaja st. 221, 443011 Samara, Russian Federation.Phone: +7/846/3344220; Fax: +7/846/3355600; E-mail [email protected] page: http://www.fian.smr.ru/rp/index.htm

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