Material Physics Lab
The Material Physics Lab focuses on the characterization of high performance materials (both polymers, metals and ceramics and composites) for aerospace, space and other high tech applications. Our experimental techniques were selected to determine and quantify the chemical and physical structure of the material and to assist our researchers in establishing the relationship between material structure and material properties. The equipment can be used by accredited AE researchers and students and others working or studying at the TU Delft. Potential users of equipment must first contact one of the staff members listed below to discuss the intended use of the equipment. If the technique is deemed suitable, instructions will be provided to the user on the methodologies and good practice in interpreting the results. Depending on the technique and the measurement time a fee may be charged. External parties can apply as well for measurement time in the Material Physics Lab (contact the staff for further information). In special cases the measurements will be done by the staff. All users must attend a pre-requisite Safety Meeting in order to obtain access to the Material Physics Lab.
In the Material Physics Lab the following techniques are available for the characterization of high performance and smart materials:
Temperature and thermal history can have a large impact on the structure and properties of materials. Changes in the compositional and structural parameters of the material affects its phase transitions and these in turn can be linked to many performance parameters.
The Material Physics Lab has expertise in conducting a variety of mechanical test experiments on structural materials at temperatures from -150 °C to +1500 °C and under different environments.
Differential scanning calorimetry
Differential scanning calorimetry (DSC) measures heat flows and temperatures that are associated with thermal transitions in a material. The technique can evaluate a number of characteristic material properties such as glass transition temperatures, melting and crystallization events, phase changes, cure kinetics or to study oxidations as well as other chemical reactions. Also enthalpy changes can be detected by the simulation of manufacturing processes.
Perkin Elmer DSC 8000
Temperature range: -180 °C up to + 750 °C
Thermogravimetry/differential thermal analysis
Thermogravimetric/Differential Thermal Analyzer (TG/DTA) combines thermogravimetry (TG) with differential thermal analysis (DTA), which has similarities with DSC. Thermogravimetry can give an indication of the materials thermal stability whereas DTA provides information about the difference in temperature between the sample and the reference when they are subjected to the same heat. The combination allows to determine whether an endothermic or exothermic transition is associated with a weight loss (e.g. loss of volatile, degradation, decomposition, oxidation, etc.) or can be attributed to a phase change in the material.
Perkin Elmer TG/DTA-7 Pyris Diamond
Temperature range: ambient to 1500 °C (under argon)
Perkin Elmer TGA 4000
Temperature range: ambient to 1000 °C
With thermomechanical analysis (TMA), knowledge can be gained about a material by imposing an external stimulus. This can be stress, strain or only temperature. The simplest mode of thermomechanical analysis is where the imposed stress is zero. In this case, the material response is generated by a thermal stress, either by heating or cooling and can be expressed in a coefficient of thermal expansion.
Perkin Elmer Diamond TMA
Temperature range: -150 °C to 1500 °C
Dynamic mechanical analysis
Dynamic mechanical analysis is an essential extension of thermal analysis, as it can reveal more subtle transitions with temperate that affect the complex modulus of the material. DMA allows to study the visco-elasticity of materials (metals, ceramics and polymers) as a function of temperature, time, frequency, stress, atmosphere or a combination of these parameters. Information can be obtained about glass transition, storage/loss modulus (tan δ), beta/gamma relaxations, degree of cross-linking, lifetime predictions and creep/stress relaxations.
Perkin Elmer Diamond DMA
Temperature range: -150 °C to 600 °C (air or inert atmosphere).
Frequency range: 0.001 – 100 Hz (max. 13 frequencies)
Maximum load range: 18 N
Testing modes: bending, tension, (film)shear, compression and 3-point bending.
A deformation-dilatometer is available for studying thermal expansion and phase transformations in metallic alloys and steel by monitoring in 2 directions the dimensional change under industrially relevant heating or cooling conditions. It can give insight in the heating rates, quenching rates and isothermal dwell times, required to yield the desired microstructure with its physical properties. Controlled deformations at a range of deformation rates can be applied prior, during and after the phase transformation.
TA Instruments DIL 805
Temperature range: -150 °C to 1500 °C ;
Deformation rates : 10-4 to 10-1 s-1
Heating rates up to 4000 °C/sec and cooling rates up to 2500 °C/sec.
With a rheometer, the steady state and time dependent viscoelastic properties of a material can be studied as a function of stress and/or strain. A special feature of our rheometer is that it is coupled to an in-situ attenuated total reflectance Fourier transform infrared spectrometer (ATR-FTIR) which enables a simultaneous study of chemical information with rheological properties over a temperature range from ambient to 400 °C. Additionally, this equipment has a controlled test chamber with solid dynamic mechanical analysis (DMA) clamps for testing the viscoelastic properties of thin films from -150 °C to 600 °C.
ThermoFischer Haake Mars III – Nicolet iS10 FT-IR
Oscillation frequency range: 10-6 Hz to 100 Hz
Normal force: 0.01 N to 50 N
Torque: 0.01 µNm to 200 mNm
A computer controlled micro-scratch tester can be used to quantify parameters such as adhesive strength and friction force of thin films and coatings with a typical thickness below 5 µm. The technique is also suitable for scientific research on abrasion resistance of materials. Finally, with the scratch tester well controlled initial surface damage can be induced in self-healing materials to quantify its subsequent healing kinetics. The tester is equipped with a hot-stage for temperature control.
CSM micro-scratch tester
Load range from 0.01 N to 30 N. Progressive, constant or incremental loading.
Our nanoindentation facility (UMIS nanoindenter system) enables to measure the mechanical properties of surfaces on a submicroscopic scale. The indenter pushes with a diamond tip into the surface of the materials being tested. The force required to push the diamond tip into the material compared to the depth of the identation determines the hardness of the material. The stiffness of the material can be determined by the degree of how the material returns to its previous shape, also given by an elastic modulus. Besides characterization of the mechanical properties, the nanoindenter can be used as a nano-scratch tester on films and coatings.
Tensile testing machine
The tensile testing machine evaluates how a material reacts to forces being applied in tension or compression. A test specimen can be secured between the rigid base frame and the crosshead. The system can move the crosshead up or down to apply a tensile or compressive load respectively on the material. A load transducer, mounted between the specimen and the crosshead, measures the applied load and converts the forces into an electrical signal. The tensile tester is equipped with a cooling and heating system.
Load cells of 1 kN and 10 N.
One three-point bending fixture and two grips for tensile testing.
For unravelling the material characteristics on microscale to macroscale, microscopy and spectroscopy techniques are very useful. Often, domains created by the material morphology are large enough to be imaged by microscopy. For the identification of the molecular structure or for the identification of functional groups, spectroscopy techniques are suitable.
The Material Physics Lab has a number of upright and inverted light microscopes (transmission, bright-field and dark-field), a 3D digital microscope (Keyence Digital Microscope VHX-2000E) and a laser scanning confocal microscope (Olympus LEXT OLS3100). The 3D digital microscope has a high-depth resolution zoom lens (500x – 5000x) and a wide-range zoom lens (100x – 1000x magnification), capable of imaging 3D-surface profiles and image stitching (both in 2D and 3D). For appropriate samples the confocal microscope allows the production of in-focus images of rough specimens, also known as optical sectioning. Point-by-point images can be acquired and reconstructed with the software, allowing three-dimensional reconstructions of topologically-complex objects.
The conventional optical microscopes are fitted with a CCD camera and quantitative image analysis software. Adequate grinding and polishing as well as etching facilities are available in labs nearby.
Scanning Electron Microscopy
Scanning Electron Microscopy provides information about the microstructure and chemical composition of a wide range of organic and inorganic materials. The scanning electron microscopy in the Material Physics Lab is configured with secondary and backscattered electron detectors as well as an energy dispersive X-ray spectrometer (EDS). EDS allows to identify and quantify the elemental composition of sample areas of a micron or less.
JEOL JSM-840 – EDS
Magnification: 20 – 300000 x with a resolution up to 3.5 nm.
A X-ray diffractometer is available for the quantitative and qualitative analysis of the crystallographic structure of polycrystalline materials and can also be used for material identification. This technique yields information on lattice spacing and after some data processing on grain size and the stress state.
Rigaku MiniFlex 600
Source : Cu
Scanning range: -3 to 145° (2θ)
Detector: NaI scintillator
Data collection: scans or step-wise
Laser Speckle Imaging
Laser Speckle Imaging (LSI) is based on the interference pattern of backscattered light when a material is illuminated by laser light. This pattern consists of dark and bright areas and is called a speckle pattern. In a static sample, the speckle pattern will be stationary. The degree of movement in the imaged area will change the speckle pattern accordingly over time and thus allows to reconstruct spatiotemporal maps of the dynamics in a material.
The Materials Physics Lab hosts a LSI set-up, equipped with a coherent laser beam (Coholt Samba, 200 mW, λ = 473 nm) and a CCD camera for high frequency recording.
Infrared spectroscopy can be used to identify both organic and inorganic compounds or investigate sample composition by measuring the absorption of light in the infrared region of the electromagnetic spectrum (7800 – 370 cm-1 with a resolution of 0.5 cm-1).
Perkin Elmer Spectrum 100
Measurement options: KBr disc sample compartment and universal ATR.
UV-Vis spectroscopy provides information on the electronic energy levels of a molecule upon absorption of ultraviolet or visible radiation. It is a suitable technique for understanding the mechanisms of electronic and optical response in various organic and inorganic materials. Furthermore, the spectrometer is equipped with an in-house stirring mechanism to investigate release mechanisms from carrier-systems in solutions.
Perkin Elmer Lambda 35
Range: 190–1100 nm
Bandwidth: 0.5 – 4 nm (variable)
Confocal Raman Microscopy
A confocal Raman microscope is available to study the Raman bands of a material with high spatial resolution. The technique provides insight in the chemical composition, structure and dynamics in a variety of materials. The confocal Raman miscroscope can be used with a motorized and/or hot stage for mapping and temperature control.
Renishaw inVia confocal Raman microscope
Spectral resolution: 0.5 cm-1
Magnification: 5x, 20x and 50x.
A variety of materials are exploited in applications as a result of electrical properties such as capacitance, resistivity, conductivity, dieelectric constant, permittivity, piezo- or pyroelectric constants etc. The Material Physics Lab hosts several techniques to characterize these properties and test the materials performance.
Dieelectric spectroscopy yields information about the dielectric properties of a material as a function of frequency. These properties depend on mobility and relaxations, and hence probe the relaxation dynamics in the material. The technique is based on the interaction of an external field with the (local) electric dipole moments in the sample. The fluctuations of the local electric fields are measured and provide insight on the dynamics on a molecular scale.
Novocontrol Impedance Analyzer
Temperature range: -150 oC to + 400 oC.
Frequency ranges of analyzers:
HP4284A 20 Hz – 1 MHz
Agilent E4991A 1 MHz – 3 GHz
HP4291 1 MHz – 1.8 GHz
Alpha-N analyzer 0.3 Hz – 20 MHz
Impedance measuring instruments are available to measure circuit components such as capacitors and inductors by using dc bias conditions and frequencies similar to those of the intended application. Here the focus is mainly on the properties of material/electrode interfaces. Typically, impedance spectra are recorded under controlled DC voltage and current conditions.
Both for dielectric spectroscopy and impedance spectroscopy, spectra can be further processed by matching nonlinear curve fitting procedures to the measured data. Results from other material characterization methods may be included in these models and can provide additional information about the material.
Frequency range 100 Hz to 20 kHz (801 spots)
Impedance range: 100 mΩ – 10 MΩ (0.1% basis accuracy)
High speed measurements (1 kHz): 95 ms/meas (4-digit display resolution; 60 ms/meas (3-digit display resolution.
HP/Agilent 4194A Impedance/Gain-Phase Analyzer
Frequency range impedance measurement: 100 Hz to 40 MHz and 10 kHz to 100 MHz,
Impedance range: 10 mΩ – 100 MΩ and 0.1 Ω – 1 MΩ
Gain-phase measurement: 10 Hz to 100 Mhz, -107 dBm to +15 dBm, 0.1 dB resolution
With our custom-build scanning thermoelectric power instrument, changes in the thermoelectric effect can be followed during heating, cooling or isothermal holding. This information reveals insight about minute yet crucial microstructural changes in alloys, such as precipitation reactions and more massive martensitic transformations. The method should be compared to electrical resistivity measurements but is more robust.
Anatech Scanning Thermo Electric Power
Temperature range of -190 °C to 250 °C with a temperature stability of < 0.01 °C.
For the investigation of the reaction mechanisms in redox related chemistry and other (electro)chemical phenomena, electrochemical equipment can be used. Two high performance potentiostats/galvanostats (Autolab PGSTAT302 and Autolab PGSTAT302N) with a compliance voltage of 30 V and a bandwidth of 1 MHz in combination with a FRA32M and a MUX module have been installed in our electrochemical lab for corrosion studies such as electrochemical impedance spectroscopy (EIS) on series of 3 electrode systems inside a faraday cage. Furthermore, a portable Bipotentiostat/galvanostat (Ivium CompactStat) is available for electrochemical experiments in combination with other measurement techniques elsewhere in our physical lab and. The equipment is especially designed to determine very small signals with a limiting current rage of ±1 nA in combination with an additional secondary working electrode setup.
An hyphenated opto-electrochemical cell has been developed as an improved method to simplify the evaluation/interpretation of the electrochemical processes at exposed metal surfaces and damages on coated metals. The technique allows for real-time acquisition of optical microscopy images and electrochemical information at the damaged or exposed site for the evaluation of e.g. corrosion inhibiting species and self-healing coatings.
A spectro-electrochemical cell kit in combination with a UV-VIS spectrometer is available to couple electrochemical experiment to measure or change the oxidation state of a solution species with the structural and quantitative capabilities of spectroscopy.
The contact angle is used to characterize the wetting properties of surfaces, by using the Young equation. The contact angle is the angle where the liquid-vapour face encounters a solid surface. Contact angle measurement can give insight in for instance cleanliness, roughness, surface heterogeneity and absorption.
The Contact Angle Measuring System G2 allows the fully automatic measurement of contact angle, surface tension of solids, surface tension and interfacial tension of liquids. The G2 is the analysis system for routine quality control. From test liquid dosing and precise positioning of samples to analysing measured data. The entire measuring cycle is fully automatic.
Kruss G2 system
For successful bonding, coating or printing of polymers and metals, the surface has to be clean and sufficiently active to form adhesive bonds with the coated materials. A plasma set-up, combined with a motorized stage is available to do ultra-fine cleaning and activation of surfaces for good wettability, without the use of chemicals. The instruments provides a potential-free plasma jet, resulting from gas discharge that is ignited between a centered electrode and a grounded nozzle.
Optical oxygen meter
The available oxygen controller (Pyro-Science FireSting O2) equipped with a 50 µm retractable needle-type oxygen sensor allows high-precision detection of oxygen levels in gases and liquids (DO) based on an optical detection technique (REDFLASH technology). The setup is equipped with a local temperature sensor and a single-axes motorized stage ( 1 µm accuracy and 13 mm travel range) to perform line-scans on various systems.