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Analyzing & Testing
Business Unit
www.netzsch.com
Thermal Analysis Methods (Part 1):
TG, DSC, STA, EGA
Practical Applications of Thermal Analysis Methods in Material Science Krakow, 15 – 16 May, 2012 Ekkehard Post, NETZSCH Gerätebau, Wittelsbacher Str. 42, D-95100 Selb/Germany
Krakow 2012/ep
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Thermal Analysis Techniques
Krakow 2012/ep
Evolved Gas Analysis (EGA – MS, FTIR, GC-MS)
Differential
Scanning
Calorimetry
(DSC, DTA)
Thermo-
gravimetric
Analysis
(TGA)
Thermo-
mechanical
Analysis (TMA)
Dilatometry
(DIL)
Dynamic-
Mechanical
Analysis (DMA)
Thermal effects
from physical
and chemical
processes
(phase
transitions,
reactions);
specific heat
Mass changes
due to
evaporation,
decomposition
and interaction
with the
atmosphere
Dimensional
changes,
deformations,
viscoelastic
properties,
transitions,
density
Dielectric
Analysis
(DEA)
Dielectr.
constant
(permittivity),
loss factor,
conductivity,
resisitivity
(ion viscosity);
cure index (degr.
of cross-linking)
Thermophysical
Properties
Laser Flash
Analysis (LFA)
Heat Flow Meter
Guarded Hot
Plate etc.
Thermal
Conductivity
Thermal
Diffusivity
Specific Heat
Thermal
Expansion
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Thermogravimetric Analysis
First thermobalance were built by Kotaro Honda in 1915, working at
Tohoku Imperial University.
With this Instrument were
obtained the first TG-curves for
MnSO4• H20, CaCO3 and
CrCO3.
Krakow 2012/ep
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Thermogravimetry (TG):
Measuring Principle
Electronic microbalance – the sample’s gravitational force is continually evened out by the
electromagnetic force.
The needed current for the equilibrium represents the measurand and is recorded.
ASTM E 473 – 85:
Thermogravimetry is a technique in which the mass of a substance is measured as a
function of temperature while the substance is subjected to a controlled-temperature
program.
Background:
- law of mass conservation
- mass change by reaction
separation/absorption of
gaseous materials
transition rate = f(m)
Krakow 2012/ep
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Arrangements of Commercial TGAs
Krakow 2012/ep
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Schematic of a Top Loading Balance
gas outlet
sample
cooling
cooling
hoistsample carrier
balancegas inletprotective
gas inletpurge
relief valve
pressure sensor
cover support
sample carrier
vacuum
Krakow 2012/ep
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TG curve
Krakow 2012/ep
100 200 300 400 500 600 700 800 900Temperature /°C
30
40
50
60
70
80
90
100
TG /%
-12.05 %
-18.81 %
-29.48 %
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TG and DTG curves
Krakow 2012/ep
100 200 300 400 500 600 700 800 900Temperature /°C
30
40
50
60
70
80
90
100
TG /%
-6.0
-5.0
-4.0
-3.0
-2.0
-1.0
0
1.0
DTG /(%/min)
-12.05 %
-18.81 %
-29.48 %
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Stainless Steel in Humid Atmosphere
Krakow 2012/ep
Sample: Stainless Steel
Sample mass: ~ 500 mg
Crucible: Alumina Plate
Heating rate: 10/0 K/min
Atmosphere: Water vapor
Sensor: TG type S
2 days isothermal at 900°C
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Differential Scanning Calorimetry /
Differential Thermal Analysis
Krakow 2012/ep
Differential Scanning Calorimetry (DSC) is a Thermal Analysis technique in which the heat flow rate (power) to the sample is monitored against time or temperature while the temperature of the sample, in a specified atmosphere, is programmed ICTA; For better Thermal Analysis and Calorimetry, Edition III (1991)
FurnaceRefer.Sample
T
QPR
.
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DTA and DSC Principle
Krakow 2012/ep
During a phase transition a temperature difference
(heat flux difference) between the sample and
reference can be measured by means of a
thermocouple.
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Generation of the DSC/DTA Signal
Krakow 2012/ep
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Magnesium Alloy
Krakow 2012/ep
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Second Order Phase Transitions - magnetic phase transition of iron (Lambda shape) -
200 400 600 800 1000 1200 1400 1600Temperature /°C
-1
0
1
2
3
4
5
6
7
DSC /(mW/mg)
Sample: Iron
1534.0 °C
1559.7 °C
266.1 J/g
926.4 °C1399.3 °C
770.2 °C 16 J/g 16.13 J/g
exoSample: Iron disk
Sample mass: 129.68 mg
Crucible: Pt+liner+lid
Sample holder: DSC-cp
Heating rate: 20 K/min
Atmosphere: Argon at 50 ml/min
melting magnetic A3 A4
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Phase diagrams - DSC
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Phase diagram of NiAl
Krakow 2012/ep
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Phase diagram of NiAl
Krakow 2012/ep
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Heat Capacity of Molydenum
Krakow 2012/ep
-200 -100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300
Temperature /°C
0.15
0.20
0.25
0.30
0.35
0.40
Spe
cific
Hea
t /J/
(g K
)
Mo: Literature
Mo: Measurement
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Simultaneous Thermal Analysis (STA)
Simultaneous Techniques
This refers to the application of two or more techniques to a (single)
sample at the same time. A hyphen is used to separate the
appreviations, e.g. simultaneous thermogravimetric analysis and
differential scanning calorimetry (TGA-DSC).
TG-DSC/DTA
Simultaneous mass change and energetic information on one and the same
sample under absolutely identical measurement conditions
ICTA 1991
Krakow 2012/ep
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Simultaneous Thermal Analysis (STA)
FurnaceRefer.Sample
T
QPR
.
TG + DSC = STA
Thermogravimetry Differential Scanning
Calorimetry
TG, DSC applied simultaneously to the same sample.
Krakow 2012/ep
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TG – DSC Measurement of Fe2O3
Krakow 2012/ep
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Heating and Cooling of MnO2
200 400 600 800 1000 1200 1400Temperatur /°C
-4
-2
0
2
4
6
DSC /(mW/mg)
86
88
90
92
94
96
98
100
102
TG /%
Sample: MnO2
619.1 °C
958.2 °C1200.7 °C
179.7 J/g
71.45 J/g
432.1 J/g
-9.20 %
-3.07 %
-0.23 %
1147.8 °C
-71.83 J/g
exo
Krakow 2012/ep
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Different Furnaces for Different Applications
Krakow 2012/ep
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Sample Carriers
Krakow 2012/ep
TG-DSC- cp
TG-DSC
TG-DTA TG
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Special STA furnaces increase
application range
Krakow 2012/ep
2400°C Furnace
Water Vapour Furnace
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Scheme of the Tungsten Furnace
Maximum heating and cooling rate: 100 K/min
Atmospheres: Helium, vacuum
Maximum temperature at sample: 2400°C
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Tungsten Furnace Guarantees very
clean Atmospheres
At 2400 °C, the vapor pressure of graphite is 10-3 torr, therefore no high vacuum can be
applied. The tungsten furnace of the STA 429 allows measurements in high vacuum
(10-5 torr) up to 2400 °C. This is essential for clean atmospheres and Knudsen cell tests
Krakow 2012/ep
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Melting and Crystallization of Vanadium
Created with NETZSCH Proteus software
1760 1780 1800 1820 1840 1860 1880 1900 1920 1940Temperature /°C
0
20
40
60
80
100
120[1.2]
TG /%
2
3
4
5
6
7
DTA /(µV/mg)
Main 2009-07-03 08:08
heating
cooling
theoretical values: melting1890°C
sample Vanadium, 20 K/min, He
1887.1 °C
1879.9 °C
-38.74 µVs/mg
38.47 µVs/mg
exo
Temperature program: RT to 1970°C to 1600°C Heating rate: 20 K/min Atmosphere: He Crucible: ZrO2 „liner“ in W crucibles
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Sapphire
Created with NETZSCH Proteus software
2000 2020 2040 2060 2080 2100Temperature /°C
6
7
8
9
10
11
12
DTA /(µV/mg)
-300
-250
-200
-150
-100
-50
0
50
100
TG /%
Main 2009-07-03 12:01
Melting of Sapphire
2nd heating
2055.0 °C
52.43 µVs/mg
exo
Temperature range: RT to 2100°C
Heating rate: 75 K/min
Crucible: W with lid
Atmosphere: He
Sample weight: 12.34 mg
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EGA methods combined with TGA
MS Mass Spectrometry
FTIR Fourier Transform Infrared
Spectroscopy
GC-MS Gas Chromatography with MS
GC-FTIR GC with FTIR
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MS Capillary Coupling
Krakow 2012/ep
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Hydromagnesite
(STA-MS Capillary)
mass 25.98 mg
temp. 25 ... 960°C
HR 10 K/min
Air, 80 ml/min
Mg5(CO3)4 (OH)2 * 4 H2O
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16th March 2011
Krakow 2012/ep
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Tools to Investigate such Events?
Krakow 2012/ep
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0
1.0
2.0
3.0
4.0
5.0
Ion Current *10-9 /A
500 600 700 800 900 1000Temperature /°C
100
102
104
106
108
110
112
114
TG /%
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
DTG /(%/min)
BCR-276
in N2 and water vapor atmosphere
5 K/min
2 amu
DTG
TG
Zircaloy Zirc-4 BCR-276
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MS-Skimmer Coupling
Krakow 2012/ep
10 mbar-1
Sample
Heater
Sample carrier
Gas overflow
Quadrupol analyzer
Ion source
Skimmer
Orifice
1013 m
bar
10 mbar-5
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Melting behaviour of CuGaSe2
Krakow 2012/ep
http://www.nrel.gov/docs/fy03osti/33997.pdf
NREL/SR-520-33997
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CuGaSe2
Krakow 2012/ep
I2
Impurities: Selenium excess, Iodine
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STA – MS – FTIR Coupling
Krakow 2012/ep
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TG – FTIR Measurement of PVC
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STA – GC – MS Coupling
Krakow 2012/ep
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Thank you for your attention