Laboratory of Corrosion Tests (contact persons: Mgr. Marián Palcut, PhD., doc. Ing. Martin Kusý, PhD., email: marian.palcut@stuba.sk; martin.kusy@stuba.sk)
The Corrosion Laboratory allows monitoring and evaluation of materials corrosion resistance. The Laboratory is equipped with a CO-FO-ME-GRA condensation chamber, an IPS potentiostat and a CORTEST device designed to monitor corrosion of materials under sstress.
The CO-FO-ME-GRA condensation chamber enables accelerated corrosion tests to be carried out in a humid and saline environment with a neutral pH, so called neutral salt spray test. The device enables the accelerated corrosion tests in compliance with the ISO 11503, ISO 1456, ISO 3768, ISO 3769, ISO 3770, ISO 4541, ISO 6270 and ISO 7253 Standards. The device also meets the requirements of the selected DIN and ASTM Standards, e.g. ASTM B117, ASTM B287, ASTM B368 and DIN 40046, DIN 50021, DIN 50907, DIN 50958 and others. Assessment of the corrosion test is performed by visual inspection. Evaluation of the overall test is possible by assessing the surface of corrosion attack or by weighing the mass loss using precise laboratory balances of Mettler Toledo.
The Laboratory also comprises a PGU 10 V-1A-IMP-S potentiostat/galvanostat which enables electrochemical corrosion tests according to the STN EN ISO 17475 Standard. The Laboratory devices enable monitoring the electro-chemical parameters of metal materials, i.e., potentio-dynamic, potentio-static and galvano-static dependencies which are used to determine corrosion rate and identify the activity/passivity areas. Electrochemical impedance spectrometry is also available to determine capacity of an electric bilayer. Corrosion resistance can be also determined volumetrically by monitoring the evolution of hydrogen released during the corrosion of low-noble metals (Mg, Al) in the aquatic environment. In the course of experiments, it is possible to control the temperature and chemical composition of the electrolyte. The Laboratory is equipped with a flow thermostat, pH meter, conductometer and the equipment for preparation of deionized water. A direct current source is also available to carry out simple electrochemical surface treatments, e.g. nickel plating.
The CORTEST device allows carrying out stress corrosion cracking tests in a corrosive environment of fluids in the range from the room temperature to 300 ° C, while applying a versatile pressure up to the maximum of 20 MPa. During the test, a circular or rectangular specimen is subjected to slow strain rate test (SST) mode or the mode of constant stress or elongation. The device also allows cyclic loading in the tensile region with a different shape of the load force course.
Laboratory of Coating (contact person: Prof. Ing. Ľubomír Čaplovič, PhD., email: lubomir.caplovic@stuba.sk)
The Laboratory of Coating in the MTF Institute of Materials deals with the preparation and evaluation of the properties of various types of high-hard PVD coatings. PLATIT π80 + DLC coating equipment installed in the Laboratory allows coating of the conventional TiN, TiCN, TiAlN, AlTiN, CrN, AlCrN or CrTiN-based coatings, as well as gradient coatings, nanocomposite TiAlSiN and AlCrSiN-coatings, multilayers and DLC coatings, depending on the cathodes used (Al, Ti, Cr and Al / Si) and the coating parameters. The device can be used for deposition of both, laboratory samples as well as tools with diameter of 300 mm and a length of 400 mm in maximum. The maximum charge weight is 50 kg. The tools made of HSS and WC/Co substrates are coated in the temperature range from 450 °C to 480 °C. In addition, the device allows plasma cleaning of substrate surfaces prior to deposition, including surface activation. The Laboratory also includes the equipment for cleaning and preparing the substrates and tools‘surface prior to the coating process, namely the Powerplus Tools SBC 420 (~ 6 bar) sand booth, the Elmasonic P ultrasonic cleaner and the Bio-Circle GT Compact degreasing bath. The applied research of the Laboratory of Coating is focused on monitoring the influence of deposition parameters on the chemical, physical and mechanical properties of nanocomposite TiAlSiN and AlCrSiN coatings. The Laboratory cooperates with the companies Staton, s.r.o. in Turany and Liss, a. s. in Rožnov pod Radhoštěm engaged in the production of cutting tools and coating deposition.
Laboratory for the Reserach and Development of Advanced Metal Materials and Composites (contact person: RNDr. Pavol Priputen, PhD., e-mail: pavol.priputen@stuba.sk)
The laboratory serves for the preparation of advanced metal materials such as high entropy alloys, complex metal alloys or various kinds of new alloys. The materials are prepared by the arc or induction melting in a protective argon atmosphere. The Laboratory comprises also equipment for sealing the prepared materials into quartz glass in protective argon atmosphere, thanks to which the materials can be further heat treated up to 1200 °C. In the Laboratory, there is also a workplace dedicated to the preparation of modified high-temperature superconducting tapes by electrolytic plating (by copper or silver), application of high capacity layers, as well as soldering of high-temperature superconducting tapes by conventional and inductive soldering.
Laboratory of Heat Treatment and Mechanical Tests (contact person: doc. Ing. Marián Hazlinger, CSc., email: marian.hazlinger@stuba.sk)
The Laboratory allows various types of mechanical testing of materials in the field of tensile testing (load up to 250 kN) in compliance with STN EN ISO 6892, Charpy impact tests in compliance with STN EN ISO 148 at room temperature and at reduced (up to -60 ° C) or elevated (up to 200 ° C) temperatures, Vickers hardness tests (HV 0.01 to HV 10) according to STN EN ISO 6507, Rockwell hardness tests according to STN EN ISO 6508 and Brinell hardness tests (HBW 750/5 and HBW with a ball of 2.5 mm in diameter for different materials) in compliance with STN EN ISO 6506, the compression, bending and double shear (load up to 400 kN) tests. The devices are in calibration state. In terms of heat treatment, available are the furnaces up to 1200 °C with air atmosphere, a furnace up to 1600 ° C with air atmosphere and furnaces with controlled atmosphere.
Laboratory of Thermo-physical Meassurements and Calculations (contact person: Ing. Marián Drienovský, PhD., email: marian.drienovsky@stuba.sk)
The Laboratory of Thermophysical Measurements and Calculations is focused on measuring and analyzing thermophysical properties of materials such as specific heat capacity, linear thermal expansion, phase transformations temperatures, length and thermal effects of phase transformations and processes, and the possibility of predicting phase equilibria and kinetic process, depending on composition and environmental conditions.
- a) NETZSCH STA 409CD simultaneous thermoanalyzer; simultaneous differential thermal and thermogravimetric analysis in the temperature range from 20 °C to 1600 °C in an inert or oxidizing atmosphere, determination of phase transformation temperature, thermal capacity, phase transformations enthalpy, mass changes, oxidation and decomposition temperatures.
- b) NETZSCH DIL 402 C Dilatometer; longitudinal changes depending on temperature variations in the temperature range from -160 °C to 1400 °C in an inert atmosphere, determination of coefficient of linear thermal expansion, density vs. Temperature ratio, temperature of phase transformations and plasticization temperature of plastics.
- c) PerkinElmer differential scanning calorimeter; determination of temperatures and enthalpy of phase transformations and heat capacity in the temperature range -70 °C to 600 °C in an inert atmosphere; the possibility of rapid heating and cooling.
- d) Database software (DICTRA, ThermoCalc, JMatPro); calculation of thermodynamic equilibria of the stable and metastable systems and phase transformation kinetics; Modeling the behaviour of materials under various processing methods and in the use (effect of time, temperature and environment).
Laboratory of Processing and Analyses of Non-metallic Materials consists of two workplaces: Laboratory of measuring low electric conductivities and Laboratory of Rheology (contact person: Prof. Ing. Marián Kubliha, PhD., email: marian.kubliha@stuba.sk)
The former Laboratory allows monitoring the electrical and dielectric properties of solid state insulators and semiconductors. It is equipped with the Novocontrol CONCEPT 90 device, fitted with a Quatro Cryosystem. The device enables measurement of temperature-stimulated depolarization currents from temperatures of - 160 ° C at charging voltage up to 250 V and also the measurement of low electrical conductivity in the DC electric field, with guaranteed sensitivity of current measurement in the range of 10 ÷ 16 A to 400 °C. The system is a standard for characterization of polarizing phenomena, especially in polymer structures and glasses, as well as transport phenomena in ceramics, glass, semiconductors and polymer-based materials.
For the modular and impedance spectroscopy of materials, there is a spectral analyzer with accessories (Solartron 1260, impedance range 1 Ω to 100 MΩ, frequency range 10 µHz to 32 MHz). It can measure a wide spectrum of electrical and dielectric parameters of a sample (conductivity, resistivity, impedance, complex permittivity) at different frequencies of electric current.
The other Laboratory is used to measure rheological properties, determine flow properties of thermoplastics and measure vulcanization curves of rubbers at various temperature and frequency measurement regimes. The Bohlin Gemini II rheometer and the MonTech D-MDR 3000 rheometer are both available.
Devices in the Institute of Materials
The Institute of Materials has built Centres of Excellence for preparation and analysis of materials. Most of the funding for the purchase of new and unique analytical instruments and equipment was obtained from the EU Structural Funds within the Science and Research Operational Program. The APRODIMET Center of Excellence was built for the purposes of Application of PROgressive DIagnostic METhods in the processing of metal and non-metallic materials. It focuses on the application of analytical methods using the latest knowledge of the electron and laser beam interaction with the state-of-the-art high sensitivity detection systems and non-electrical quantities.
The methods used comprise the evaluation of specific properties of progressive metal and non-metallic materials. The Centre contributes to the improvement of both, the research infrastructure in the Trnava region and the educational process as well as popularisation of science and technology in the general public. It comprisess the Laboratory of Thermophysical Measurements and Calculations, which is an integral part of the scientific approach to the design, analysis and optimisation of technological processes for the production and processing of progressive materials using the physical and computer modeling techniques and numerical simulation of material behaviour, supplemented with experimentally determined thermophysical properties. Unlike real experiments, computer simulation makes it possible to study the given phenomenon in more detail and to observe a significantly higher number of physical quantities in relation to each other.
Based on the qualitative and quantitative evaluation of the results, we can predict the behaviour of materials under different loads and the boundary conditions simulating the production process and identify the determinants affecting the investigated process and identify the causes of undesirable phenomena. Real thermophysical data over a wide temperature range are needed to calculate the temperature fields and deformations by the finite element method (FEM). They can be measured by simultaneous thermoanalysis (combination of thermogravimetry, differential thermal analysis and differential scanning calorimetry, or mass spectroscopy of reactive gaseous thermal decomposition products). Thermal expansivity is measured using a dilatometer operating at a temperature range of -160 °C to 2000 °C, while thermal diffusivity, in turn, is measured using a laser pulse analyzer. Measurement of the temperature-stimulated depolarization currents from the temperatures of - 160 °C at a charging voltage of up to 250 V, as well as the measurement of low electrical conductivities in the DC electric field is carried out by the apparatus measuring the electrical properties. The maximum measurement temperature with guaranteed sensitivity of the electric current measurement 10 ÷ 16 A achieves 400 °C for a used measuring cell. The system represents two standards for the characterization of polarizing phenomena, particularly in polymer structures and glasses, as well as transport phenomena in ceramics, glasses, semiconductors and polymer-based materials.
Spectrum analyzer with accessories, used for the modular and impedance spectroscopy of materials and interfaces, is able to measure a wide spectrum of electrical and dielectric parameters of a sample (conductivity, resistivity, impedance, complex permittivity) at different frequencies of electric current. The Laboratory is fitted with the following experimental equipment and appropriate simulation software:
- NETZSCH STA 409 CD /7/403/5/G, a simultaneous thermoanalyzer with a mass spectrometer for the temperatures from 20 to 2000 °C;
- NETZSCH DIL 402 C/7/G + C75, a high-temperature dilatometer operating in the range -160 to 2000 °C;
- NETZSCH LFA 427/7/G, a laser flash analyzer for determination of temperature diffusivity in the temperature range from 20 to 2000 °C;
- TSDC System CONCEPT 90 with Quatro Cryosystem extension, an apparatus for measuring electrical properties with a focus on linear heating and thermal resistance;
- SOLATRON spectrum analyzer with accessories;
- DEFORM Software for simulation analyses of deformation processes in materials;
- SYSWELD Software for modeling and simulating the thermal and stress-strain states of materials in the heat treatment and welding processes;
- JMatPro Software for calculation of material properties of multicomponent alloys with thermodynamic databases;
- Thermodynamic databases - minerals and carbides, solutions and pure materials, steels/Fe alloys, Al alloys and light alloys, ceramic systems.
The Laboratory of Corrosion Tests is equipped with the top laboratory technology to determine the level of corrosion processes in metals and their degradation. It focuses mainly on the scientific and research activities in the areas of the metal materials protection from corrosion and metal surface treatment. The instrumentation enables to design solutions to improve the condition of technical equipment, renovation procedures and corrosion protection of components and whole assemblies. Modern unique devices allow measurement of electrochemical characteristics enabling the detection of instantaneous corrosion rate of metals, their susceptibility to the atmospheric, pitting or intergranular corrosion and the ability to passivate in various work environments, as well as many other corrosion properties of materials allowing the correct selection of material and work environment in terms of corrosion.
- PGU 10V potentiostatic test equipment,
- CorrosionBox 400E mist chamber
- CORTEST stress corrosion testing equipment.
The Laboratory of Structural Analyses is equipped with the state-of-the-art microscopes (the electron, light and laser ones). Scanning high-resolution electron microscope with the EDX, WDX and EBSD detectors can identify chemical composition and crystallographic characteristics in micro-volumes of the analysed materials. The “gentle beam” technique allows even non-conductive samples to be observed. The microscope is preferably intended for analysis of surface layers of the metal and non-metallic materials in the real state (degradation, fractography), as well as in materiallographic sections. The laser confocal microscope allows 3D visualization of the surface layer and quantification of thevheight irregularities up to 20 nm.
Two laser sources allow analysing the surface of the samples in fluorescent light, thus enabling to detect organic substances. The aparatus is used to analyse degraded surfaces which are due to the abrasive, adhesive, cavitation, fatigue and corrosion wear, as well as to determine the roughness after application of technological operations. The X-ray diffractometer is primarily used to investigate the impact of external parameters and technological processes on the qualitative and quantitative characteristics of structural components, while emphasising the evaluation of internal and external deformations of crystal lattice, which are both due to the atom redistribution and the thermal, tribological and physico-chemical effects of the external environment, such as determination of residual stress levels in the depth profile of heat treated parts, structural refinement of new and modified phases with regard to the currently solved UMAT projects, determination of coherent scattering area size, and texture analyses of the deformed and cast systems. A high-temperature chamber for in situ analysis of material complexes will be also included. The diffractometer is equipped with the state-of-the-art detection systems that increase the measurement sensitivity, resolution and rate. Databases of the diffraction and crystallographic data are included. A list of all analytical devices and auxiliary equipment is given below:
- JEOL 7600F high resolution scanning electron microscope with EDX, WDX and EBSD analyzers;
- Philips CM 300 transmission electron microscope with LaB6 and GATAN SC 200 Orius digital camera;
- ZEISS LSM 700 laser confocal microscope;
- PanAnalytical EMPYREAN, a multifunctional X-ray diffractometer for phase analyses in the temperature range from 20 to 1100 °C;
- FRITSCH spherical micrometer, PULVERISETTE 7 model;
- Gatan ultrasonic disc cutter;
- JEOL SM-09010_CP sample preparation equipment for EBSD (Cross Section Polisher - CP).
The Laboratory of Coating, Heat Treatment and Mechanical Testing is designed to provide suitable experimental materials with a specific structure of surface layers and a defined structure in the core. These are mainly the coatings fabricated by both, PVD processes as well as by classical methods of cementation, nitrocementation, carbonitriding and nitriding. The Laboratory comprises also a device for testing mechanical properties of the metal and non-metallic materials according to the valid STN EN ISO 7500-1, DIN 51220, DIN 51221, STN EN 6892, DIN 51223, DIN 51227, ASTM E-4, VDE 0113, ISO 5893 Standards and other international standards. The maximum loading force is 250 kN. The device also includes a temperature chamber up to 1000 °C. An instrumented impact pendulum hammer is used to measure the impact energy versus the force and deflection of the specimen according to STN EN ISO 14556 and in accordance with STN EN ISO 148-1. The maximum impact energy of this device is 300 J. Both, the instrumented and non-instrumented brits can be used for the measurement. The high-speed imaging camera records the deformation pattern on the outside of the test sample. Samples can be tested at -70 to + 270 (+500) °C. The type designation of individual devices is listed below:
- Platit PI 80 + DLC coating equipment for coating TiN, AlTiN, CrN, AlCrN, etc.
- LAC, a multifunctional laboratory furnace for nitriding, cementation and nitrocementing
- LABORTECH LabTest 5.250 Sp1 testing machine
- CHK-300, an instrumented impact pendulum hammer
- Arc melting furnace for small quantities of materials
- Induction melting furnace