Microstructural and Chemical Analyses
Department of Microstructural and Chemical Analyses
- Ing. Ján Kepič, PhD.
( jkepic(at)imr.saske.sk , +421-55-7922 427 )
- Ing. Karol Kovaľ
( kkoval(at)imr.saske.sk , +421-55-7922 424 )
- Helena Červeňáková
( hcervenakova(at)saske.sk , +421-55-7922 454 )
- Ing. Juraj Ďurišin, CSc.
( jdurisin(at)saske.sk , +421-55-7922 435, 495 )
- Ing. Róbert Džunda
( rdzunda(at)saske.sk , +421-55-7922 424 )
- Želmíra Kandráčová
( zkandracova(at)saske.sk , +421-55-7922 438 )
- RNDr. Ján Mihalik
( jmihalik(at)saske.sk , +421-55-7922 403,455 )
- Edita Ridarčíková
( eridarcikova(at)saske.sk , +421-55-7922 438 )
Laboratory of microstructural and chemical analyses (LMCHA) belongs to the Laboratory departments of IMR SAS.
The major objective of LMCHA research group is to investigate microstructural and chemical properties of metal and ceramic materials in relation to their physical and mechanical properties, by using light and electron microscopy techniques, X-ray diffraction and chemical methods. LMCHA disposes of many activities focused on fundamental material research, collaborates with universities, research institutes and industrial subjets on national and international level.
Special attention is devoted to the East Slovak region.
LMCHA is experienced in preparation of relatively large area of powder and compacted materials - metals, ceramics and composites and determination of:
- microstructure and morphology via light microscopy and electron microscopy
- grain/crystallite size and strain, internal stresses
- hardness and microhardness
- qualitative and quantitative chemical analysis by EDS and AAS methods
- IC, DSC and DTA analysis
- development of chemical analytical methods
- chemical synthesis of materials
- phase composition and crystal orientation via EBSD and TEM techniques
- phase qualitative and quantitative analysis by X-ray diffraction analyses
- electric properties measurement
- covering of metal and ceramic materials by PVD method
- fractography and failure analysis
Metallographic cuts for microstructure observation and analysis (light and electron microscopy) can be prepared by the following techniques:
• mechanical polishing of metal, ceramic and composite materials
• electrochemical polishing of metal (composite) materials
• ion bombing of metal and ceramic material
Optical (light) microscopy
Microstructures are studied by optical microscopy for dimensional measurement down to 1 micrometer. The method includes bright field, dark field, polarized illumination, differential interference contrast observations. Obtained images are recorded in digital form by camera. The laboratory is equipped with two kind of metallographic microscopes: Olympus GX 71 and Neophot 32.
Scanning electron microscopy
The scanning electron microscopy (SEM) provides topographical and compositional information about samples at much greater magnifications and depth of field than is possible with light microscopy. The combination of SEM Jeol JSM 7000F with analytical units EDX, EBSD Oxford Instruments provides an unique qualitative and quantitative datasets suitable for chemical/elemental and phase compositions.
Similar equipment for routine work with magnification up to 20 000 is SEM Tesla BS 340 with EDX unit.
Information from SEM can be displayed in a variety of ways, as spectra, numerical data, line scans and X-ray dot maps showing the distribution of elements.
Transmission electron microscopy
The transmission electron microscopy (TEM) is used to characterize the microstructure of materials with very high spatial resolution. Information about the morphology, crystal structure and defects, crystal phases and composition can be obtained by a combination of electron-optical imaging, electron diffraction and small probe capabilities. The transmission electron microscope uses a high energy electron beam transmitted through a very thin sample.
The laboratory is equipped with TEM Tesla BS 500 having accelerating voltages 90 kV. Sample preparation for TEM generally requiring more time and experiences compared to the SEM technique. Specimens for TEM must be sufficiently thin (in range of tens nanometers) in order to be transparent for incoming electrons. Thus, thin foils are prepared by electropolishing and by focused ion beam methods.
Observation of carbon replica is also very desired and frequent.
The X-ray diffraction laboratory
The X-ray diffraction laboratory provides very valuable crystallographic information about a wide variety of materials e.g.: metal, ceramic and composite specimens. Here it is capable to determine phase compositions, quantitative portions of phases (in some favourable cases) and crystallite sizes together with macro/micro stresses. Measurements can be carried out at elevated temperatures in protected atmosphere or vacuum, investigating phase transformation of ferrous and non-ferrous materials. The laboratory is equipped with X-ray diffractometer Philips X`Pert Pro.
The main objective of chemical laboratory is to develop new analytical methods for non standard materials, provide the elemental qualitative and quantitative analyses and develop synthesis process of new inorganic materials.
Thermo DTA-DSC-TG analyzer of series Jupiter STA 449-F1 from NETZSCH. The device is used for investigation of phase analysis and kinetics of phase transformation under anisotermal conditions in temperature range 20ºC to 1650ºC. The device is procured in frame of structural found "Technology of preparation of electrotechnical steels possesing high permeability for high affectivity electromotors" ITMS 26220220037.
Ion Cutter 682 PECS from Gatan, Inc. The device is designed for cutting, etching and/or coating samples by the instrumentality of ion beam. Ion cutter is used to prepare samples for ELMI analysis. The instrument also serves for deposition of various conductive elements on the surface of samples for SEM, TEM and EBSD analysis. The device is procured in frame of structural founds projects "Research Centrum for effectiveness of combined systems and renewable energy resources intergration" ITMS 26220220064.
Electrolytic polisher LectroPol-5 from Struers. The device is used for sample preparation for SEM, EBSD analysis by means of electrolytic polishing/etching electrolyte. Fully automatic microprocessor controlled device with external electrolytic polishing equipped with thermostat for ensuring working electrolyte temperature in range -70 to 200°C. The device is procured in frame of structural found "Technology of preparation of electrotechnical steels possesing high permeability for high affectivity electromotors" ITMS 26220220037.
The Nano Indenter G200 from Agilent Technology is the most advanced platform for exploring material properties at the nano and micro scales. The Nano Indenter G200 system is a flagship instrument for performing nanoindentation experiments, its capabilities extend to other modes of testing; such as scratch testing and nanomechanical microscopy and you can perform a variety of different tests. The device is procured in frame of structural found project "New materials and technologies for energetics" ITMS 26220220061.
Present key equipments at LMCHA:
- JEOL JSM-7000F Multi-Purpose High Performance Thermal Field Emission SEM,
the Schottky type field emission electron gun makes it possible to achieve very stable electron beam, the microscope is equipped by Oxford Instruments Analytical Units:
- EDS system - providing elemental analysis from sub-micron volume
- EBSD unit - for phase identifications and crystal orientation analysis
- SEM Tesla BS 340 with EDS unit LINK
- TEM Tesla BS 500, 90kV
- Electrolytical polishing equipment
- Ion polishing equipment - preparation of thin foils for TEM
- X - ray diffractometer Philips X`Pert Pro equipped by:
- high temperature camera up to 1600°C,
- ultra-fast detector - X`Celerator; (100 x faster then the conventional scintillation or Geiger type)
- diffracted beam monochromator (for scanning materials containing Fe)
- Light microscopes – Olympus GX 71, Neophots
- Microhardness tester – Leco
- Atomic absorption spectrometer (AAS)
- Precise impedance analyser – AGILENT 4294A