thermal diffusivity and thermal conductivity by...

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www.netzsch.com Analyzing & Testing Business Unit LFA for Thermal Diffusivity and Conductivity of Metals, Ceramics and Polymers Ramón Arauz Lombardia, Service & Applications NETZSCH-Gerätebau GmbH, Branch Office Barcelona, Spain

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Page 1: Thermal Diffusivity and Thermal Conductivity by LFAsamssa.eu/fileadmin/samssa/downloads/workshop/presentations/... · Thermal Diffusivity and Thermal Conductivity by LFA ... Thermal

www.netzsch.com

Analyzing & Testing

Business Unit

LFA for Thermal Diffusivity and Conductivity of

Metals, Ceramics and Polymers

Ramón Arauz Lombardia, Service & Applications

NETZSCH-Gerätebau GmbH, Branch Office Barcelona, Spain

Page 2: Thermal Diffusivity and Thermal Conductivity by LFAsamssa.eu/fileadmin/samssa/downloads/workshop/presentations/... · Thermal Diffusivity and Thermal Conductivity by LFA ... Thermal

www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 1

Agenda

1. Heat Transfer - Basics

2. LFA - Method

3. LFA - Instrumentation

4. Application Examples

5. Summary

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 2 2

Examples of Heat Transfer

From Everyday Life

..cooling the microprocessor chip in a laptop computer

2

Heat Transfer – Electronics

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 3 3

Examples of Heat Transfer

From Everyday Life

3

Photo: BMW AG – Photo-Gallery: 3 Series

Thermal Conductivity – Automotive Industry

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 4 4

Heat Transfer - Basics

4

x

Tq

x

TTAQ

;12

Heat transfer (or heat) is the energy in transit (energy moving

through a material) due to a temperature difference.

A quantitative expression relating the rate of heat transfer, the

temperature gradient and the nature of the conducting medium is

attributed to Fourier (1822):

Jean Baptiste Joseph Fourier

Heat flux = heat

flow rate per unit

area in direction x

- thermal

conductivity

of material

A – area normal to heat flow

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 5 5

Heat Transfer - Basics

There are three main modes of heat transfer:

Conduction: molecular interactions or free electrons

Convection: exchange of heat between a fluid and a surface or an

interface.

Radiation: no medium required, electromagnetic phenomenon

Stefan-Boltzmann constant

Thermal conductance varies for each mode of heat transfer

5

4TA

q

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 6 6

Heat Transfer Basics

6

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 7 7

Thermal Conductivity Measurement Methods

7

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 8

Agenda

1. Heat Transfer - Basics

2. LFA - Method

3. LFA - Instrumentation

4. Application Examples

5. Summary

Page 10: Thermal Diffusivity and Thermal Conductivity by LFAsamssa.eu/fileadmin/samssa/downloads/workshop/presentations/... · Thermal Diffusivity and Thermal Conductivity by LFA ... Thermal

www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 9 9

Heat Transfer – LFA Method

9

The measurement of the thermal diffusivity of a material is usually carried out

by rapidly heating one side of a sample and measuring the temperature rise

curve on the opposite side.

The time that it takes for the heat to travel through the sample and cause the

temperature to rise on the rear face can be used to measure the through-plane

diffusivity and calculate the through-plane thermal conductivity if the specific heat

and density are known.

All three quantities as well as the thermal diffusivity can be functions of

temperature.

TTcTaT p

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 10 10

Heat Transfer – LFA Method

10

Flash Method:

Measurement Principle

Introduced by Parker et al. 1961

The front surface of a plan-parallel sample

is heated by a short light or laser pulse.

The temperature rise on the rear surface is

measured versus time using an IR detector.

The sample has been stabilized at the desired

temperature, the laser fired several times over a span

of a few minutes and the necessary data is recorded

for each laser „shot“. The laser beam energy strikes and is absorbed by the front surface of the sample,

causing a heat pulse to travel through the samples‘ thickness. The resulting sample temperature rise is

fairly small, ranging from 0.5 to 2 °C. The temperature rise is amplified and recorded.

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 11 11

Heat Transfer – LFA Method

11

2/1

2

1337.0t

da

pcmT

1max

TTcTaT p

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Heat Transfer: LFA Method

Polymer (slow) Metal (average) Graphite (fast)

Half-times

Thermal Diffusivity and Thermal Conductivity by LFA

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 13

Agenda

1. Heat Transfer - Basics

2. LFA - Method

3. LFA - Instrumentation

4. Application Examples

5. Summary

Page 15: Thermal Diffusivity and Thermal Conductivity by LFAsamssa.eu/fileadmin/samssa/downloads/workshop/presentations/... · Thermal Diffusivity and Thermal Conductivity by LFA ... Thermal

www.netzsch.com

Flash Technique – Introduction Netzsch LFA Systems for almost all application ranges

14

LFA 457 MicroFlash®

-125°C to 1100°C

Sample changer for 3

samples

Thermal Diffusivity and Thermal Conductivity by LFA

LFA 467 HyperFlash

-100°C to 500°C

Sample changer for 16

samples

ZoomOptics - IR detector

Fastest data acquisition

LFA 427

-120°C to 2800°C

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NETZSCH LFA 467 HyperFlash

Table-top instrument

Works with a high power Xenon-Flash

lamp

Temperature range: -100 to 500°C

Integrated sample changer for

16 samples

Different cooling options

ZoomOptics for optimized field of view

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NETZSCH LFA 467 HyperFlash ̶ ZoomOptics

No Zoom Optics — Distortion from Aperture

Field of view is fixed, large enough to cover big diameter

samples.

Testing smaller diameter samples, apertures are used

minimizing the influence of the surroundings.

Significant distortion of the thermal curve: detector not

only senses the temperature rise of the sample, but also any

fluctuations from the aperture.

Thermal curve shows either a continuously increasing

trend or an extended leveling-off period.

Distortion from Aperture

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NETZSCH LFA 467 HyperFlash ̶ ZoomOptics

Zoom Optics — No Distortion from Aperture

IR signal originates solely from the sample surface

Large and small samples can be tested with an

optimal sensing area.

No contributions from the aperture

Thermal curve conforms to the theoretical model, yielding correct diffusivity values.

No Distortion from Aperture

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NETZSCH LFA 467 HyperFlash ̶

High Sample Throughput

Highest Sample Throughput ̶

High Efficiency

16 Pyroceram samples (2.5

mm thick, 12.7 mm)

Thermal diffusivity shows a

deviation of ±2% from

literature data.

Optimum position for each of

the 16 samples in the

furnace over the entire

temperature range.

Reduced measurement time

High throughput possible

without operator‘s

intervention

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NETZSCH LFA 467 HyperFlash ̶

Thin and High Conductive Materials

Thin and High Conductive—Copper Copper samples with different thicknesses from 3.0 mm to

0.25 mm.

Measurements confirm that even very thin samples can be tested with very high accuracy.

Sample preparation and thickness determination have to be carefully considered when measuring thin samples. Especially graphite coating can lead to lower thermal diffusivity values.

0,1 1 10

0

10

90

100

110

120

130

Th

erm

al d

iffu

sivi

ty [m

m²/

s]

Sample Thickness [mm]

LFA467

Literature

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NETZSCH LFA 457 MicroFlash®

Table-top unit with laser

Temperature range: -125 to 1100 °C

(with two furnaces)

Integrated sample changer for 3 samples

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Vertical system

Two exchangeable furnaces

• -125 … 500°C

• RT … 1100°C

Vacuum-tight (1 Pa)

Laser pulse length ~ 0.33 ms

LFA 457 MicroFlash® Design

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LFA 457 MicroFlash®

Sample Changer

Multiple Sample Arrangement12.7 mm dia. and 10.0 mm square

Single Sample Arrangement25.4 mm dia.

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Standard Application Stainless Steel

0.40

0.45

0.50

0.55

0.60

0.65

Sp

ecific

He

at / (J

/(g

*K)

0 100 200 300 400 500 600 700 800 Temperature / °C

2

3

4

5

6

Th

erm

al D

iffu

siv

ity / m

m²/

s

Thermal Diffusivity

Specific Heat

DSC 404 Test

SRM 1461 - Stainless Steel

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Application – Filled Rubber

-125 -100 -75 -50 -25 0 25 50 75 100

Temperature / °C

0.0

0.1

0.2

0.3

0.4

Therm

al D

iffusi

vity

/ m

m²/

s

Sample: Filled NR/BR

Thickness: 1.512 mm

Width: 12.70 mm

0.0

0.1

0.2

0.3

0.4

0.5

Therm

al C

onduct

ivity

/ W

/(m

*K)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Speci

fic H

eat / J/

(g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

LFA 457 Microflash®

Sample: Filled NR/BR

Thickness: 1.512 mm

Width: 12.7 mm

Thermal Diffusivity

Thermal Conductivity

Specific Heat

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Temperature range -120 to 2800°C

Vacuum-tight design 1*10-5 mbar

Different sample holders

standard sample holder

square sample holder

laminate sample holder

fiber sample holder

slag sample holder

liquid metal sample holder

Thermophysical Properties Testing

NETZSCH LFA 427

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NETZSCH LFA 427

The system is vacuum-tight by

design.

Laser, sample and detector are in

line (No mirrors are used)

Improved signal-to-noise ratio.

One single system covers the

temperature range from room

temperature to 2000°C

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250 500 750 1000 1250 1500 1750 2000 2250 Temperature / K

0

1

2

3

4

5

Therm

al D

iffu

siv

ity / m

m²/

s

LFA 427

Sample thickness: 4.01 mm

Sample holder: Graphite

Heating rate 6.5 K/min

Atmosphere: Argon

Application: Silicon Carbide

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Laser Flash Instrument Setup:

NETZSCH LFA 427/8/G Pyro

Temperature range: RT to 2800°C

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Conclusion

NETZSCH offers a full range of flash systems (Xenon and laser

based) for a broad application range.

The LFA 447 NanoFlash allows for scanning the sample’s surface

-> MTX.

The LFA 467 HyperFlash offers optimum performance for thin and

high conductive materials in the temperature range from -100°C to

500°C. The integrated ZoomOptics guarantees for an optimized

field of view and precise results.

The LFA 457 MicroFlash® is the right research instrument for

applications from -125°C up to 1100°C.

The LFA 427 fulfills the requirements of extreme temperatures and

special application ranges.

Thermal Diffusivity and Thermal Conductivity by LFA

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 30 30

LFA Software

30

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 31 31

LFA Technique

31

Some Reasons for the Success of the Flash Technique:

1. The method covers a broad measurement range

(0.01 … 1000 mm²/s, 0.05 … 2000 W/(m*K))

2. The laser flash technique can easily be adapted to temperature-

dependent tests (-125 … 2800°C)

3. Sample preparation is easy

4. It is a non-contact, non-destructive measurement technique

5. It can be employed on multi-layer systems

6. Fast testing times (generally a few seconds)

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 32

Agenda

1. Heat Transfer - Basics

2. LFA - Method

3. LFA - Instrumentation

4. Application Examples

5. Summary

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 33 33

Thermal Diffusivity of Metals: Cu and Al Comparison to Literature Values

0 100 200 300 400 500 600

Temperature / °C

50

60

70

80

90

100

110

120

130

140

150

Th

erm

al D

iffu

sivi

ty /

mm

²/s

Aluminum - Measurement

Copper - Measurement

Aluminium - Literature

Copper - Literature

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 34 34

Polycarbonate (PC) in an Aluminum Container

34

In the Tg range the specific heat (Cp) rises from 1.5 to 1.8 J/gK (typical for 2nd order transitions).

The thermal conductivity () shows a continuous progression. Although the thermal diffusivity (a)

decreases constantly after the Tg, of the amorphous material continues to increase due to the

increasing Cp and amounts to 0.3 W/mK at 300 °C (thus at injection moulding temperature).

0 80 160 240 320

Temperature / °C

0.05

0.10

0.15

0.20 T

herm

al D

iffusi

vity

/ m

m²/

s

Sample: PC

Thickness: 1.05 mm

Width: 11.00 mm

0.0

0.1

0.2

0.3

0.4

0.5

Therm

al C

ondu

ctiv

ity /

W/(

m*K

)

1

2

3

4

Speci

fic H

eat / J/

(g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

In the range of the clearly recognizable glass transition

(Tg) the thermal diffusivity drops significantly

from 0.125 to 0.1 mm2/s between 130 to 150°C.

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 35 35

Liquids and Molten Polymers in an

Aluminum Container

35

Lid

CrucibleSample

Aluminum Sample holder forLow-Viscosity Liquids

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 36 36

Polyamide PA 46 Influence of the Filler Content

36

PA 46 alone has a very low thermal conductivity. With increasing filler (Al2O3) content in the

polymer the specific heat decreases while the thermal diffusivity and conductivity increase.

0 10 20 30 40 50 60 70

Alumina content /%

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0T

herm

al D

iffusiv

ity /

mm

²/s

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Th

erm

al C

ond

uctiv

ity /

W/(

m K

)

0.0

0.4

0.8

1.2

1.6

2.0

Sp

ecifi

c H

eat

/J/(

g*K

)

Thermal Diffusivity thru plane

Thermal Conductivity thru plane

Specific Heat

Thermal Diffusivty in-plane

Thermal Conductivity in-plane

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Polyetheretherketone (PEEK) Filled with

Carbon Nanotubes (CNT)

Prepared in Cooperation with:

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PEEK filled with CNT - Anisotropy

Orientation of Carbon Nanotubes due to injection moulding

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Pure PEEK Matrix

10 30 50 70 90 110 130 150 170 190 210Temperature / °C

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

Therm

al D

iffu

siv

ity / m

m²/

s

Sample: PEEK ohne CNT

Thickness: 3.030 mm

Density (25°C): 1.294 g/cm³

0.0

0.1

0.2

0.3

0.4

0.5

Therm

al C

onductivity / W

/(m

*K)

0

1

2

3

Specific

Heat / J/(

g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

Sample: PEEK without CNT

10 30 50 70 90 110 130 150 170 190 210Temperature / °C

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

Therm

al D

iffu

siv

ity / m

m²/

s

Sample: PEEK ohne CNT

Thickness: 3.030 mm

Density (25°C): 1.294 g/cm³

0.0

0.1

0.2

0.3

0.4

0.5

Therm

al C

onductivity / W

/(m

*K)

0

1

2

3

Specific

Heat / J/(

g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

10 30 50 70 90 110 130 150 170 190 210Temperature / °C

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

Therm

al D

iffu

siv

ity / m

m²/

s

Sample: PEEK ohne CNT

Thickness: 3.030 mm

Density (25°C): 1.294 g/cm³

0.0

0.1

0.2

0.3

0.4

0.5

Therm

al C

onductivity / W

/(m

*K)

0

1

2

3

Specific

Heat / J/(

g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

39

Glass transition

Thermal Diffusivity and Thermal Conductivity by LFA

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PEEK Filled with 7% CNT

10 30 50 70 90 110 130 150 170 190 210 Temperature / °C

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.22

0.24

Th

erm

al D

iffu

siv

ity / m

m²/

s

Sample: PEEK with 7% CNT

Thickness: 3.020 mm

Density (25°C): 1.323 g/cm³

0.0

0.1

0.2

0.3

0.4

0.5

0.6

Th

erm

al C

ond

uctivity /

W/(

m*K

)

0

1

2

3

Sp

ecific

He

at / J/(

g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

Thermal conductivity increases by 14%

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PEEK Filled with 14% CNT

10 30 50 70 90 110 130 150 170 190 210 Temperature / °C

0.0

0.1

0.2

0.3

0.4

Th

erm

al D

iffu

siv

ity / m

m²/

s

Sample: PEEK mit 14% CNT

Thickness: 2.920 mm

Density (25°C): 1.358 g/cm³

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Th

erm

al C

ond

uctivity /

W/(

m*K

)

0.0

0.8

1.6

2.4

3.2

Sp

ecific

He

at / J/(

g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

Thermal conductivity increases by 45%

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Increasing Thermal Conductivity with Increasing

CNT Content

0 5 10 15

mass-% CNT

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

The

rmal

Con

duct

ivity

/W/(

m K

)

Sample: PEEK mit 0-14% CNT

Thickness: 3 mm

Density (25°C): 1.3 g/cm³

25°C

100°C

200°C

Thermal Diffusivity and Thermal Conductivity by LFA

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In-plane sample holder

Anisotropy: In-Plane Sample Holder

Vertical direction

through-plane

Horizontal direction

In-plane

Thermal Diffusivity and Thermal Conductivity by LFA

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PEEK with CNT – Anisotropy

10 30 50 70 90 110 130 150 170 190 210 Temperature / °C

0.0

0.1

0.2

0.3

0.4

Th

erm

al D

iffu

siv

ity / m

m²/

s

Sample: PEEK with 14% CNT

Thickness: 2.920 mm

Density (25°C): 1.358 g/cm³

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Therm

al C

onductivity /

W/(

m*K

)

0.0

0.8

1.6

2.4

3.2

Sp

ecific

He

at / J/(

g*K

)

Thermal Diffusivity

Thermal Conductivity

Specific Heat

In-Plane (In the plate direction, center)

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Easy sample preparation

Only for higher thermal conductivities (e.g. metals, ceramics, graphite)

Only for thin samples (<1mm thickness)

Key Advantages of Netzsch LFA Systems High sensitivity opens the doors for smallest sample dimension

Thermal Diffusivity and Thermal Conductivity by LFA 45

Created with NETZSCH Proteus software

Identity

xxx

xxx

Sample

081

081

Thickness /mm

3,6300

3,6300

Material

081

081

Atmosphere

Ar

Ar

Date/Time

2011-09-19 10:00:29

2011-09-16 09:23:03

Calc. code

mix/l/0-0-1

C+p/mx/0-0-1

0 50 100 150 200 250 300 350 400

Temperature /°C

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

Th

erm

al D

iffu

siv

ity /

(mm

^2

/s)

Heating -->

<-- Cooling

Low conducting thermoelectric material with bad dimension

Diameter = 6 mm; Thickness = 3.6 mm (recommended: 12.6 / 2 mm)

-2000 -1000 0 1000 2000 3000 4000 5000 6000 7000

Time /ms

-1

0

1

2

3

4

5

6

7

8

Sig

nal/V

Medium pulse energy for all shots!

Detector signal Small noise level

at bad conditions

~5 Joule sufficient

No overheating of

sample

Reliable results

SbxCoSb3-x

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Easy sample preparation

Only for higher thermal conductivities (e.g. metals, ceramics, graphite)

Only for thin samples (<1mm thickness)

Key Advantages of Netzsch LFA Systems Wrong results without pulse length correction

Thermal Diffusivity and Thermal Conductivity by LFA 46

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

Pulse Length / ms

100

110

120

130

140

150

160

170

180

190

200

Th

erm

al

Dif

fusi

vity

/ m

m²/

s

Sample: Silver

Thickness: 1.416 mm

Diameter: 10.29 mm

With New Pulse Length Correction

Without Pulse Length Correction

Literature Value Theoretical Half

Time: 1.6 ms

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Key Advantages of Netzsch LFA Systems Now we measure thinner samples thanks to 2 MHz data acquisition

Thermal Diffusivity and Thermal Conductivity by LFA 47

0,1 1 10

0

10

20

30

40

50

60

70

80

90

100

110

120

130

Th

erm

al d

iffu

siv

ity [m

m²/

s]

Sample Thickness [mm]

LFA 467

Literature

Copper with a thickness < 1mm is possible now

250 µm

2 MHz and 10 µs pulse length

were not possible in the past!

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Key Advantages of Netzsch LFA Systems High accuracy at low viscosity liquids like water, oils …

48 Thermal Diffusivity and Thermal Conductivity by LFA

20 30 40 50 60 70 80 90

Temperature /°C

0.00

0.05

0.10

0.15

0.20

0.25 T

herm

al D

iffu

siv

ity / m

m²/

s

Sample Holder No. 1

Sample Holder No. 2

Sample Holder No. 3

Literature Values +/- 5%

Water

Liquids (PEEK) Sample Holder

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Key Advantages of Netzsch LFA Systems Liquid metals (Sapphire) sample holder

49 Thermal Diffusivity and Thermal Conductivity by LFA

Liquid Metals (Sapphire) Sample Holder

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Key Advantages of Netzsch LFA Systems Pressure sample holder for compressible samples

50 Thermal Diffusivity and Thermal Conductivity by LFA

CNT Powders with different particle sizes

Pressure Sample Holder

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Easy sample preparation

Only for higher thermal conductivities (e.g. metals, ceramics, graphite)

Only for thin samples (<1mm thickness)

Key Advantages of Netzsch LFA Systems LFA must be gas tight for pressure depending measurements

Thermal Diffusivity and Thermal Conductivity by LFA 51

20 40 60 80 100 120 140 160 180 200 220

Temperature / °C

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Th

erm

al C

ond

uctivity /

W/(

mK

)

Sample: YOM2 (compressed between 2 graphite coated saphire discs)

Density (original / compressed): 1.360 / 1.423 g/cm³

Thickness (original / compressed): 1.130 / 1.080 mm

Mechanical Pressure: 2 bar (~2.5 kg on sample surface)

~940 mbar (ambient)

40 mbar25 mbar

15 mbar

5 mbar

Why it must be gas

tight?

for low pressure

measurements

Temp. < 10°C (to

avoid condensation)

Temp. > 300°C (to

save graphite

coating)

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Easy sample preparation

Only for higher thermal conductivities (e.g. metals, ceramics, graphite)

Only for thin samples (<1mm thickness)

Key Advantages of Netzsch LFA Systems Automatic model wizard for detection of best model fit

Thermal Diffusivity and Thermal Conductivity by LFA 52

Standard model

Deviations after shot

due to radiation

-1000 0 1000 2000 3000 4000 5000 6000

Time /ms

-1

0

1

2

3

4

5

6

Sig

nal/V

-1000 0 1000 2000 3000 4000 5000 6000

Time /ms

-1

0

1

2

3

4

5

6

Sig

nal/V

Radiation model

Excellent fit after shot

Consideration of

radiation

Model Wizard

Oxide Ceramics at 900°C

Oxide Ceramics at 900°C

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Easy sample preparation

Only for higher thermal conductivities (e.g. metals, ceramics, graphite)

Only for thin samples (<1mm thickness)

Key Advantages of Netzsch LFA Systems Automatic model wizard for detection of best model fit

Thermal Diffusivity and Thermal Conductivity by LFA 53

More than 8% error if standard (wrong) model is used!

Model Wizard

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 54

Agenda

1. Heat Transfer - Basics

2. LFA - Method

3. LFA - Instrumentation

4. Application Examples

5. Summary

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 55 55

Summary

55

The LFA method allows fast and reliable measurement of the thermal

diffusivity/conductivity of solids and liquids over a broad temperature

range.

Due to the speed of the method and the high accuracy, more and

more researchers replace existing stationary methods with the flash

technique.

Even critical sample geometries such as liquid metals or multi-layer

samples can be analyzed using this method.

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www.netzsch.com Thermal Diffusivity and Thermal Conductivity by LFA 56 56 56

Thank you very much for your attention !