calorimetry on pure substances and complex non … · buyco, davis 1970 brooks 1969 ditmars 1985...

Calorimetry on pure substances and complex non-equilibrium Al-systems

08.07.2016 UNIVERSITY OF ROSTOCK | CHAIR OF MATERIALS SCIENCE & POLYMER PHYSICS GROUP

Richard Kemsiesa

Benjamin Milkereita,b,c, Christoph Schickb,c, Olaf Kesslera,c

a,b,cUniversity of Rostock, Germany aChair of Materials Science,

bPolymer Physics Group cCALOR Calorimetry and Thermal Analysis Laboratory Rostock

GTT-Technologies' 18th Annual Users' Meeting

Herzogenrath, Germany

June 29 - July 1, 2016

08.07.2016 UNIVERSITY OF ROSTOCK | CHAIR OF MATERIALS SCIENCE & POLYMER PHYSICS GROUP 2

• Motivation

• Differential Scanning

Calorimetry on Aluminium

alloys

• DSC Step Scan method

for cp measurement

heating

heat treatment of metallic materials

e. g. steels, Ni- & Co based superalloys, Al alloys, …

basic scheme applies for several materials

08.07.2016 3© 2009 UNIVERSITY OF ROSTOCK | CHAIR OF MATERIALS SCIENCE & POLYMER PHYSICS GROUP

ageing

T

t

solution annealing

SAT

RTC0

600

400

200

0

lα+l

α

α+β

CB

quenching

How slow to

dissolve everything?

full solution

How fast to freeze

supersaturated

solid solution?

avoid precipitation


• Motivation



alloys


for cp measurement

08.07.2016 5© 2009 UNIVERSITY OF ROSTOCK | CHAIR OF MATERIALS SCIENCE

S: sample furnace; R: reference

furnace (equal S), 1heating wire,

2 Thermopile; measuring

systems – separately – in

ambience of const. temperature

G.HÖHNE, W. HEMMINGER, H.FLAMMERSHEIM:

Differential Scanning Calorimetry, SPRINGER

Differential Scanning Calorimetry (DSC)

2 identical micro furnaces in symmetric system

PC controlled temperature programs: heating/ cooling

regulation: equal temperature

difference in heating power or heat flow measured

measurement of (tiny) heat

Differential Scanning Calorimetry (DSC)

ideal:

heating/ cooling empty system: signal = 0

thermal reaction in sample furnace: Signal ≠ 0

real:

certain asymmetry: device depending bending

correct: subtract baseline from sample measurement

functional principle

08.07.2016 6© 2009 UNIVERSITÄT ROSTOCK

Δ P

T

0

Δ P

T

0

specific reaction

heat

sample

measurement

baseline

100 200 300 400 500

0,9

1,0

1,1

exosp

ecific

he

at

in J

g-1K

-1temperature in °C

100 200 300 400 500

0,00

0,02

0,04

0,06

ecxe

ss s

pe

cific

he

at

in J

g-1K

-1

temperature in °C

exo

Preliminary tests Al alloys

cooling EN AW-6005A , 50 K/min

Perkin-Elmer Pyris 1

after: 540 °C 20 min

How to measure precipitation heat – Cp or excess-Cp?

08.07.2016 7

alloyed sample

pure Al sample

alloyed sample

empty

© UNIVERSITY OF ROSTOCK | CHAIR OF MATERIALS SCIENCE & POLYMER PHYSICS GROUP

100 200 300 400 500

-10

-5

0

5

heat

flow

in m

W

900 mg EN AW-6005A

without any package

100 200 300 400 500-2

0

2

heat

flow

in m

W

3600 mg EN AW-6005A

wrapt in pure Al-foile

100 200 300 400 500-1

0

1

2

3

4

°C

°C

heat

flow

in m

W

temperature in °C

1570 mg EN AW-6005A

packed in pure Al crucible

Preliminary tests Al alloys

important role of radiation losses

baseline stability

samples change surface color:

bright dark grey

radiation effect changing bending

bending reduction sample package!

Obligatory sample package!

08.07.2016 8

Sample-measurement

Baseline-measurement

subtraction of sample- &

baseline-measurement

Setaram 121 DSC

cooling with 0.5 K/min after

solution annealing: 540°C 20 min


DSC measures heat effects

sample compared with inert reference sample

9© UNIVERSITY OF ROSTOCK | CHAIR OF MATERIALS SCIENCE & POLYMER PHYSICS GROUP

T

t

0 100 200 300 400 500 600-0.3

-0.2

-0.1

0.0

0.1

0.2

exothermic

AA6005A initial T4

temperature in °C

0.05 K/s

endothermic

exce

ss C

p in

Jg

-1K

-1

Challenge

Very large scale of technically & physically interesting heating & cooling rates!

10

1E-4 1E-3 0,01 0,1 1 10 100 1000 10000 100000

cooling rate in K/s

e.g. one cooling method – different component dimensions

MMG GmbH

auto-lexikon.de

weloe.de

fi-sch.de


range depends on physical requirements alloy, heating/cooling procedure, dimensions

How to cover all relevant rates?

Use different DSC types and methods

08.07.2016 11UNIVERSITY OF ROSTOCK | CHAIR OF MATERIALS SCIENCE & POLYMER PHYSICS GROUP

10-5

10-4

10-3

10-2

10-1

100

101

102

103

104

105

Milkereit et al., Thermochim. Acta 492 (2009) 73-78.

Zohrabyan et al.

Thermochim. Acta 529 (2012) 51-58.

Schumacher et al.

Thermochim. Acta

602 (2015) 63-73.

indirect

"Differential Reheating"

Chip Calorimeter, e. g.

Mettler-Toledo Flash DSC

Me

ttle

r-T

ole

do D

SC

82

3

0.1

s

1 s1 m

in

1 h1 d

1 m

o cooling rate in K/s

cooling duration 540 °C 20 °C

1 a

0.0

1 s

1 w

e

Seta

ram

C600 D

SC

Seta

ram

12

1 D

SC

Perk

in-E

lme

r P

yris 1

DS

C

indirect

"Reheating"

Setaram

121 DSC &

C600 DSC

direct in-situ cooling experiments

Continuous heating DSC AA6005A to 580 °C

suppression of reactions with increasing

rate

serious peak shift, e. g. peak b:

observed T: 160 K

thermal lag 10 K

0.01 – 5 K/s


0 100 200 300 400 500 600

initial T4

temperature in °C

0.1 K/s

0.05 K/s

0.01 K/s

0.5

Jg

-1K

-1

0.5 K/s

5 K/s

1 K/s

3 K/s

endo

exce

ss s

pe

cific

he

at

160 K

T

t

b

J. Osten et al.. Dissolution and Precipitation Behaviour during

Continuous Heating of Al–Mg–Si Alloys in a Wide Range of Heating

Rates. Materials 2015, 8, 2830-2848. DOI: 10.3390/ma8052830

0 100 200 300 400 500 600

initial T4

temperature in °C

0.1 K/s

0.05 K/s

0.01 K/s

0.5

Jg

-1K

-1

0.5 K/s

5 K/s

1 K/s

3 K/s

endo

challenges for interpretation of DSC heating curves

DSC measures sum signal!

sum might be zero...

separation of overlapped reactions problem to

solve in future

serious overlapping several reactions


t

Jg-1

K-1

0endo

exo

Continuous cooling precipitation diagrams


T

t

α α + β

α α + B‘

precipitation start temperature

08.07.2016 15

0,5 mass% Mg2Si1

540

liquid

liquid


mass % Si Mg …

1.23 1.05 …

mass % Si Mg …

0.4 0.44 …

Milkereit, B., et al. (2009). "Recording

of continuous cooling precipitation

diagrams of aluminium alloys."

Thermochimica Acta 492: 73-78. DOI:

10.1016/j.tca.2009.01.027

100 µm

Method

Which reactions occur when and how intensive?

16

tem

pera

ture

time

α α+ β

α

Which?

When & how

strong?

Structure analysis

Differential

Scanning

Calorimetry

t

T

100 200 300 400 500

0,00

0,05

cooling of an aluminium alloy

Jg-1

K-1

temperature in °C

exo


time

10 µm

CCP-diagrams

Milkereit, B., et al. (2012). "Continuous cooling precipitation

diagrams of Al-Mg-Si alloys." Materials Science & Engineering A

550: 87-96. DOI: 10.1016/j.msea.2012.04.033


• Motivation



alloys


for cp measurement

cp measurement with DSC

high accuracy through step scan method


Al crucible

sample

hea

t flo

w

time

T

tem

pera

ture

sample sample

empty

𝑄𝑠𝑎𝑚𝑝𝑙𝑒 − 𝑄𝑒𝑚𝑝𝑡𝑦𝑑𝑡

𝑚 ∆𝑇

cp

temperature

C. Schick (2002): Temperature modulated differential scanning calorimetry

(TMDSC)- basics and applications to polymers In: Handbook of Thermal

Analysis and Calorimetry. Vol. 3: Applications to Polymers and Plastics

S.Z.D. Cheng, editor, pp. 713-810.

validity of the data?

calibration with sapphire


-100 0 100 200 300 400 500 600

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

cp

in J

/(g

K)

temperature in °C

sapphire literature

cp of sapphire (Al2O

3)

0.990

0.995

1.000

1.005

1.010

1.015

1.020

lite

ratu

re / m

ea

sure

men

t

• well known cp of sapphire

• after each sample measurement

error correction

sapphire literature

sapphire measurement

-100 0 100 200 300 400 500 600

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.15

1.20

uncorrected

cp in J

/(gK

)

temperature in °C

cp of Al5N5 (Al 99.995%)

uncorrected

corrected

correction factor

evaluating the data

comparison cp of pure Al with different literature sources


-273.15 -73.15 126.85 326.85 526.85 726.85

0 200 400 600 800 1000

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

0

5

11

16

22

27

32

38

cp

in J

/(m

ol K

)

temperature in K

DSC device 1

DSC device 2

Takahashi, 1989

Buyco, Davis 1970

Brooks 1969

Ditmars 1985

cp

in J

/(g

K)

temperature in °C

-100 100 300 500

173.15 373.15 573.15 773.15

0.8

0.9

1.0

1.1

1.2

22

24

27

30

32

cp

in J

/(m

ol K

)

temperature in K

DSC device 1

DSC device 2

Takahashi, 1989

Buyco, Davis 1970

Brooks 1969

Ditmars 1985

cp

in J

/(g

K)

temperature in °C

high correspondence between

literature and measurement

step scan application on intermetallic phases

aluminium alloys for long-term stable

electrical aluminium connections (ALLEE)

large collaborative project (GTT, Hydro Aluminium,

TU Dresden, RWTH Aachen)

goal:

long-term stable intermetallic phases (e.g. Al3Zr, Al3Ni)

also at elevated temperatures (140 °C)

challenge:

prediction (modelling) of precipitation and dissolution/growth

investigation of Al alloy: sum cp of all phases

solution:

investigation of pure intermetallic phases (Uni Jena, Germany)

why important?


very difficult to produce!

intermetallic phases


results

pure intermetallic phases Al3Zr, Al13Fe4, Al3Ni, Al10Fe3Ni


150 300 450 600 750 9000.4

0.5

0.6

0.7

0.8

0.9

Al3Zr

Cp in J

/(g

K)

Temperatur in K

150 300 450 600 750 9000.4

0.5

0.6

0.7

0.8

0.9

Al10Fe3Ni

Cp in J

/(g

K)

Temperatur in K

150 300 450 600 750 9000.4

0.5

0.6

0.7

0.8

0.9

Al13Fe4

cp

in

J/(

gK

)

Temperatur in K

150 300 450 600 750 9000.4

0.5

0.6

0.7

0.8

0.9

Al3Ni

cp

in

J/(

gK

)

Temperatur in K

-100 100 300 500 700

173.15 373.15 573.15 773.15 973.15

0.5

0.6

0.7

0.8

13

16

19

22

temperature in K

cp

in J

/(m

ol K

)

Cp

in

J/(

gK

)

temperature in °C

Al3Zr-Fit

Al10Fe3Ni-Fit

Al13Fe4-Fit

Al3Ni-Fit


10-4

10-3

10-2

10-1

100

101

102

103

104

0

10

20

30

40

50

60

406080100120140160180200

HV

1 a

fter

agein

g

exce

ss c

p in

J/g

cooling rate in K/s

cooling EN AW-Al Zn8MgCu from 470 °C

0 100 200 300 400 500

0.00

0.05

0.10

0.15

0.20

0.25

cooling of EN AW-7150 after 480 °C 1 h

exce

ss c

p in

Jg

-1K

-1

temperature in °C

0.3 K/min

15 K/min

180 K/min

exo

-100 100 300 500 700

173.15 373.15 573.15 773.15 973.15

0.5

0.6

0.7

0.8

13

16

19

22

temperature in K

cp in J

/(m

ol K

)

Cp in J

/(gK

)

temperature in °C

Al3Zr

Al10Fe3Ni

Al13Fe4

Al3Ni

calorimetry on pure substances and complex non … · buyco, davis 1970 brooks 1969 ditmars 1985...

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