Analyzing & Testing Business Unit 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 www.netzsch.com Thermal Analysis Techniques Thermo- Thermophysical Differential Thermo- mechanical Dielectric Properties Scanning gravimetric Analysis (TMA) Analysis Calorimetry Analysis Dilatometry (DEA) Laser Flash Analysis (LFA) (DSC, DTA) (TGA) (DIL) Heat Flow Meter Dynamic- Guarded Hot Mechanical Analysis (DMA) Plate etc. Thermal effects Dielectr. Thermal Mass changes Dimensional from physical constant Conductivity due to changes, and chemical (permittivity), Thermal evaporation, deformations, processes loss factor, Diffusivity decomposition viscoelastic (phase conductivity, Specific Heat and interaction properties, transitions, resisitivity Thermal with the transitions, reactions); (ion viscosity); Expansion atmosphere density specific heat cure index (degr. of cross-linking) Evolved Gas Analysis (EGA – MS, FTIR, GC-MS) Krakow 2012/ep www.netzsch.com Thermogravimetric Analysis With this Instrument were obtained the first TG-curves for MnSO4• H20, CaCO3 and CrCO3. First thermobalance were built by Kotaro Honda in 1915, working at Tohoku Imperial University. Krakow 2012/ep www.netzsch.com Thermogravimetry (TG): Measuring Principle Background: - law of mass conservation - mass change by reaction separation/absorption of gaseous materials transition rate = f(m) .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. Krakow 2012/ep www.netzsch.com Arrangements of Commercial TGAs Krakow 2012/ep www.netzsch.com Schematic of a Top Loading Balance gas outlet cover support sample sample carrier cooling gas inlet vacuum purge cooling pressure sensor hoist sample carrier relief valve balance gas inlet protective Krakow 2012/ep www.netzsch.com TG curve TG /% 100 -12.05 % 90 80 -18.81 % 70 60 -29.48 % 50 40 30 100 200 300 400 500 600 700 800 900 Temperature /°C Krakow 2012/ep www.netzsch.com TG and DTG curves TG /% DTG /(%/min) 100 1.0 -12.05 % 90 0 80 -1.0 -18.81 % 70 -2.0 60 -3.0 -29.48 % 50 -4.0 40 -5.0 30 -6.0 100 200 300 400 500 600 700 800 900 Temperature /°C Krakow 2012/ep www.netzsch.com Stainless Steel in Humid Atmosphere 2 days isothermal at 900°C Sample: Stainless Steel Sample mass: ~ 500 mg Crucible: Alumina Plate Heating rate: 10/0 K/min Atmosphere: Water vapor Sensor: TG type S Krakow 2012/ep www.netzsch.com Differential Scanning Calorimetry / Differential Thermal Analysis Furnace Sample Refer. QPR T 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) Krakow 2012/ep www.netzsch.com DTA and DSC Principle During a phase transition a temperature difference (heat flux difference) between the sample and reference can be measured by means of a thermocouple. Krakow 2012/ep www.netzsch.com Generation of the DSC/DTA Signal Krakow 2012/ep www.netzsch.com Magnesium Alloy Krakow 2012/ep www.netzsch.com Second Order Phase Transitions - magnetic phase transition of iron (Lambda shape) - DSC /(mW/mg) Sample: Iron disk exo Sample mass: 129.68 mg 7 Crucible: Pt+liner+lid Sample holder: DSC-cp Heating rate: 20 K/min 6 Atmosphere: Argon at 50 ml/min 1559.7 °C 5 Sample: Iron 4 3 266.1 J/g 2 1399.3 °C 926.4 °C 1 770.2 °C 16 J/g 16.13 J/g 0 1534.0 °C magnetic A3 A 4 melting -1 200 400 600 800 1000 1200 1400 1600 Temperature /°C Krakow 2012/ep www.netzsch.com Phase diagrams - DSC Krakow 2012/ep www.netzsch.com Phase diagram of NiAl Krakow 2012/ep www.netzsch.com Phase diagram of NiAl Krakow 2012/ep www.netzsch.com Heat Capacity of Molydenum 0.40 Mo: Literature Mo: Measurement 0.35 0.30 0.25 Specific Heat /J/(g K) 0.20 0.15 -200 -100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 Temperature /°C Krakow 2012/ep www.netzsch.com 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). ICTA 1991 TG-DSC/DTA Simultaneous mass change and energetic information on one and the same sample under absolutely identical measurement conditions Krakow 2012/ep www.netzsch.com Simultaneous Thermal Analysis (STA) Furnace Sample Refer. QPR T TG + DSC = STA Thermogravimetry Differential Scanning Calorimetry TG, DSC applied simultaneously to the same sample. Krakow 2012/ep www.netzsch.com TG – DSC Measurement of Fe2O3 Krakow 2012/ep www.netzsch.com Heating and Cooling of MnO2 TG /% DSC /(mW/mg) exo 102 -0.23 % 6 100 619.1 °C 98 4 958.2 °C 96 Sample: MnO2 1200.7 °C -9.20 % 2 71.45 J/g 94 432.1 J/g 179.7 J/g 0 92 -71.83 J/g 90 1147.8 °C -2 -3.07 % 88 -4 86 200 400 600 800 1000 1200 1400 Temperatur /°C Krakow 2012/ep www.netzsch.com Different Furnaces for Different Applications Krakow 2012/ep www.netzsch.com Sample Carriers TG-DSC TG-DTA TG TG-DSC- cp Krakow 2012/ep www.netzsch.com Special STA furnaces increase application range 2400°C Furnace Water Vapour Furnace Krakow 2012/ep www.netzsch.com Scheme of the Tungsten Furnace Maximum temperature at sample: 2400°C Maximum heating and cooling rate: 100 K/min Atmospheres: Helium, vacuum Krakow 2012/ep www.netzsch.com 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 www.netzsch.com Melting and Crystallization of Vanadium TG /% DTA /(µV/mg) [1.2] 120 sample Vanadium, 20 K/min, He 7 exo 100 6 theoretical values: melting1890°C 38.47 µVs/mg 80 1887.1 °C 5 heating 60 4 40 cooling 1879.9 °C Temperature program: RT to 1970°C to 1600°C -38.74 µVs/mg 3 20 Heating rate: 20 K/min Atmosphere: He Crucible: ZrO2 „liner“ in W crucibles 0 2 1760 1780 1800 1820 1840 1860 1880 1900 1920 1940 Temperature /°C Main 2009-07-03 08:08 Krakow 2012/ep www.netzsch.com Created with NETZSCH Proteus software Sapphire TG /% DTA /(µV/mg) exo 100 Temperature range: RT to 2100°C 12 50 Heating rate: 75 K/min Crucible: W with lid 11 0 Atmosphere: He Sample weight: 12.34 mg 52.43 µVs/mg -50 10 Melting of Sapphire -100 9 2nd heating -150 8 -200 2055.0 °C 7 -250 -300 6 2000 2020 2040 2060 2080 2100 Temperature /°C Main 2009-07-03 12:01 Krakow 2012/ep www.netzsch.com Created with NETZSCH Proteus software EGA methods combined with TGA . MS Mass Spectrometry . FTIR Fourier Transform Infrared Spectroscopy . GC-MS Gas Chromatography with MS . GC-FTIR GC with FTIR www.netzsch.com Krakow 2012/ep MS Capillary Coupling Krakow 2012/ep www.netzsch.com Hydromagnesite (STA-MS Capillary) Mg5(CO3)4 (OH)2 * 4 H2O mass 25.98 mg temp. 25 ... 960°C HR 10 K/min Air, 80 ml/min www.netzsch.com Krakow 2012/ep 16th March 2011 Krakow 2012/ep www.netzsch.com Tools to Investigate such Events? Krakow 2012/ep www.netzsch.com Zircaloy Zirc-4 BCR-276 DTG /(%/min) TG /% Ion Current *10-9 /A 5.0 0.8 114 TG 0.7 112 4.0 BCR-276 0.6 110 in N2 and water vapor atmosphere 0.5 DTG 5 K/min 3.0 108 0.4 106 2.0 0.3 104 0.2 102 2 amu 1.0 0.1 100 0.0 0 500 600 700 800 900 1000 Temperature /°C Krakow 2012/ep www.netzsch.com MS-Skimmer Coupling Quadrupol analyzer 10 -5 mbar Ion source 10 -1 mbar Skimmer Orifice Sample r a Heater b m 3 1 0 Sample carrier 1 Gas overflow Krakow 2012/ep www.netzsch.com Melting behaviour of CuGaSe2 http://www.nrel.gov/docs/fy03osti/33997.pdf NREL/SR-520-33997 Krakow 2012/ep www.netzsch.com CuGaSe2 I2 Impurities: Selenium excess, Iodine Krakow 2012/ep www.netzsch.com STA – MS – FTIR Coupling Krakow 2012/ep www.netzsch.com TG – FTIR Measurement of PVC www.netzsch.com Krakow 2012/ep STA – GC – MS Coupling Krakow 2012/ep www.netzsch.com Thank you for your attention Krakow 2012/ep www.netzsch.com .