Mateusz Kopeć, M.Sc., Eng.

Department of Experimental Mechanics (ZMD)
Division of Strength of Materials (PWM)
position: assistant
telephone: (+48) 22 826 12 81 ext.: 262
room: 035
e-mail: mkopec

Recent publications
1.Ranachowski Z., Ranachowski P., Dębowski T., Brodecki A., Kopeć M., Roskosz M., Fryczowski K., Szymków M., Krawczyk E., Schabowicz K., Mechanical and non-destructive testing of plasterboards subjected to a hydration process, Materials, ISSN: 1996-1944, DOI: 10.3390/ma13102405, Vol.13, No.10, pp.2405-1-18, 2020
Abstract:

The aim of this study was to investigate the effect of plasterboards' humidity absorption on their performance. Specimens' hydration procedure consisted of consecutive immersing in water and subsequent drying at room temperature. Such a procedure was performed to increase the content of moisture within the material volume. The microstructural observations of five different plasterboard types were performed through optical and scanning electron microscopy. The deterioration of their properties was evaluated by using a three-point bending test and a subsequent ultrasonic (ultrasound testing (UT)) longitudinal wave velocity measurement. Depending on the material porosity, a loss of UT wave velocity from 6% to 35% and a considerable decrease in material strength from 70% to 80% were observed. Four types of approximated formulae were proposed to describe the dependence of UT wave velocity on board moisture content. It was found that the proposed UT method could be successfully used for the on-site monitoring of plasterboards' hydration processes.

Keywords:

plasterboards, moisture content, hydration processes, mechanical properties, ultrasound measurements

Affiliations:
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Dębowski T.-IPPT PAN
Brodecki A.-IPPT PAN
Kopeć M.-IPPT PAN
Roskosz M.-AGH University of Science and Technology (PL)
Fryczowski K.-Silesian University of Technology (PL)
Szymków M.-other affiliation
Krawczyk E.-other affiliation
Schabowicz K.-Wroclaw University of Science and Technology (PL)
2.Kopeć M., Jóźwiak S., Kowalewski Z.L., A novel microstructural evolution model for growth of ultra-fine Al2O3 oxides from SiO2 silica ceramic decomposition during self-propagated high-temperature synthesis, Materials, ISSN: 1996-1944, DOI: 10.3390/ma13122821, Vol.13, No.12, pp.2821-1-11, 2020
Abstract:

In this paper, experimental verification of the microstructural evolution model during sintering of aluminum, iron and particulate mullite ceramic powders using self-propagated high-temperature synthesis (SHS) was performed. The powder mixture with 20% wt. content of reinforcing ceramic was investigated throughout this research. The mixed powders were cold pressed and sintered in a vacuum at 1030 °C. The SHS reaction between sintered feed powders resulted in a rapid temperature increase from the heat generated. The temperature increase led to the melting of an aluminum-based metallic liquid. The metallic liquid infiltrated the porous SiO2 ceramics. Silicon atoms were transited into the intermetallic iron-aluminum matrix. Subsequently, a ternary matrix from the Fe-Al-Si system was formed, and synthesis of the oxygen and aluminum occurred. Synthesis of both these elements resulted in formation of new, fine Al2O3 precipitates in the volume of matrix. The proposed microstructural evolution model for growth of ultra-fine Al2O3 oxides from SiO2 silica ceramic decomposition during SHS was successfully verified through scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS) analysis and X-ray diffraction (XRD).

Keywords:

intermetallics, powder methods, electron microscopy, X-ray analysis

Affiliations:
Kopeć M.-IPPT PAN
Jóźwiak S.-other affiliation
Kowalewski Z.L.-IPPT PAN
3.Liu X., Kopeć M., Fakir O., Qu H., Wang Y., Wang L., Li Z., Characterisation of the interfacial heat transfer coefficient in hot stamping of titanium alloys, International Communications in Heat and Mass Transfer, ISSN: 0735-1933, DOI: 10.1016/j.icheatmasstransfer.2020.104535, Vol.113, pp.104535-1-14, 2020
Abstract:

The interfacial heat transfer coefficient (IHTC) for titanium alloys is an important parameter in non-isothermal hot stamping processes to determine the temperature field as well as temperature-dependent material behaviours that consequently affect the post-form properties of the formed components. However, the IHTC for titanium alloys in hot stamping processes has seldom been studied before. In the present research, the effects of contact pressure, lubricant, surface roughness, tooling material and initial blank temperature on the IHTC for the titanium alloy Ti-6Al-4V were studied and modelled to characterise the IHTC values under various hot stamping conditions as well as identify the functional mechanisms affecting the IHTC. Furthermore, the results of hot stamping of Ti-6Al4V wing stiffener components were used to verify the simulation results of the temperature field of the formed component with an error of less than 5%.

Keywords:

interfacial heat transfer coefficient (IHTC), Ti-6Al-4V, hot stamping, experimental validation

Affiliations:
Liu X.-other affiliation
Kopeć M.-IPPT PAN
Fakir O.-other affiliation
Qu H.-AVIC Manufacturing Technology Institute (CN)
Wang Y.-Beijing Aeronautical Manufacturing Technology Research Institute (CN)
Wang L.-Imperial College London (GB)
Li Z.-AVIC Manufacturing Technology Institute (CN)
4.Ranachowski Z., Ranachowski P., Brodecki A., Kopeć M., Kúdela Jr S., Quasi-static and dynamic testing of carbon fiber reinforced magnesium composites, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.24425/amm.2020.132836, Vol.65, No.2, pp.893-899, 2020
Abstract:

Two types of composites, consisting of pure magnesium matrix reinforced with two commercially used carbon fibers, were systematically studied in this paper. The composites fabricated by the pressure infiltration method, were subjected to quasistatic and dynamic compression tests. Morphology of fiber strands was observed using scanning electron microscope (SEM). The application of carbon fibre reinforcement led to the stiffening of tested materials, resulting in the limitation of the possible compression to approx. 2.5%. The performed tests revealed the remarkable difference in compression strength of investigated compositions. The cause of that effect was that GRANOC fiber reinforced composite exhibited insufficient bond quality between the brittle fibers and the ductile matrix. T300 reinforced composite presented good connection between reinforcement and matrix resulting in increased mechanical properties. Investigated composites demonstrated higher mechanical strength during deformation at high strain rates. Microscopic observations also proved that the latter fibers with regular shape and dense packaging within the filaments are proper reinforcement when designing the lightweight composite material.

Keywords:

Mg matrix composite, compressive properties, carbon fiber, Split-Hopkinson pressure bar

Affiliations:
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Brodecki A.-IPPT PAN
Kopeć M.-IPPT PAN
Kúdela Jr S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
5.Levintant-Zayonts N., Starzyński G., Kopeć M., Kucharski S., Characterization of NiTi SMA in its unusual behaviour in wear tests, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2019.05.005, Vol.137, pp.313-323, 2019
Abstract:

The manuscript presents experimental investigations of an unusual behaviour of shape memory alloys (NiTi) having different characteristic temperatures in wear test. The studies are focused on the different wear mechanism at varying loads and sliding times and include a description of the phenomena accompanying the wear process. The ball-on-plate reciprocating sliding wear tests were conducted on NiTi shape memory alloys against a sapphire ball. We show that the wear resistance of NiTi is affected by its specific stress-strain characteristic. The understanding of the tribological behaviour of NiTi, a knowledge of the course of wear and an examination of its mechanisms can enable an effective prevention of the destruction of devices components and prolong their safe working life.

Keywords:

wear behaviour of NiTi SMA, friction coefficient, superelasticity, shape memory effect

Affiliations:
Levintant-Zayonts N.-IPPT PAN
Starzyński G.-IPPT PAN
Kopeć M.-IPPT PAN
Kucharski S.-IPPT PAN
6.Li Z., Qu H., Chen F., Wang Y., Tan Z., Kopeć M., Wang K., Zheng K., Deformation behavior and microstructural evolution during hot stamping of TA15 sheets: experimentation and modelling, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12020223, Vol.12, No.2, pp.223-1-14, 2019
Abstract:

Near-α titanium alloys have extensive applications in high temperature structural components of aircrafts. To manufacture complex-shaped titanium alloy panel parts with desired microstructure and good properties, an innovative low-cost hot stamping process for titanium alloy was studied in this paper. Firstly, a series of hot tensile tests and Scanning Electron Microscope (SEM) observations were performed to investigate hot deformation characteristics and identify typical microstructural evolutions. The optimal forming temperature range is determined to be from 750 °C to 900 °C for hot stamping of TA15. In addition, a unified mechanisms-based material model for TA15 titanium alloy based on the softening mechanisms of recrystallization and damage was established, which enables to precisely predict stress-strain behaviors and potentially to be implemented into Finite Element (FE) simulations for designing the reasonable processing window of structural parts for the aerospace industry.

Keywords:

TA15, hot stamping, phase evolution, deformation, modelling

Affiliations:
Li Z.-AVIC Manufacturing Technology Institute (CN)
Qu H.-AVIC Manufacturing Technology Institute (CN)
Chen F.-AVIC Manufacturing Technology Institute (CN)
Wang Y.-Beijing Aeronautical Manufacturing Technology Research Institute (CN)
Tan Z.-Imperial College London (GB)
Kopeć M.-IPPT PAN
Wang K.-Imperial College London (GB)
Zheng K.-Imperial College London (GB)
7.Jozwik P., Kopeć M., Polkowski W., Bojar Z., Dynamic deformation tests of Ni3Al based intermetallic alloy by using the split Hopkinson pressure bar technique, Journal of Mining and Metallurgy, Section B: Metallurgy, ISSN: 1450-5339, DOI: 10.2298/JMMB181113014J, Vol.55, No.1, pp.129-134, 2019
Abstract:

In this work, the Ni3Al-based intermetallic alloy was subjected to room temperature dynamic plastic deformation tests by using a split Hopkinson pressure bar technique. The dynamic compression processes were carried out at strain rates in the range of ε=(1.9×10^2 ÷ 1×10^4 s^-1). A strong impact of applied deformation conditions on microstructure and mechanical properties evolution in the examined Ni3Al intermetallic, was documented. Generally, very high maximum compressive stress values were obtained, reaching 5500 MPa for the sample deformed at the highest strain rate (i.e. ε=1×10^4 s^-1). The results of performed SEM/EBSD evaluation point towards an occurrence of dynamic recovery and recrystallization phenomena in Ni3Al samples deformed at high strain rates.

Keywords:

Ni3Al-based alloy, split Hopkinson pressure bar, SEM/EBSD analysis

Affiliations:
Jozwik P.-Military University of Technology (PL)
Kopeć M.-IPPT PAN
Polkowski W.-Foundry Research Institute (PL)
Bojar Z.-Military University of Technology (PL)
8.Kopeć M., Wang K., Politis D.J., Wang Y., Wang L., Lin J., Formability and microstructure evolution mechanisms of Ti6Al4V alloy during a novel hot stamping process, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ISSN: 0921-5093, DOI: 10.1016/j.msea.2018.02.038, Vol.719, pp.72-81, 2018
Abstract:

A novel hot stamping process for Ti6Al4V alloy using cold forming tools and a hot blank was presented in this paper. The formability of the material was studied through uniaxial tensile tests at temperatures ranging from 600 to 900 °C and strain rates ranging from 0.1 to 5 s-1. An elongation ranging from 30% to 60% could be achieved at temperatures ranging from 750 to 900°C respectively. The main microstructure evolution mechanisms varied with the deformation temperature, including recovery, phase transformation and recrystallization. The hardness of the material after deformation first decreased with the temperature due to recovery, and subsequently increased mainly due to the phase transformation. During the hot stamping tests, qualified parts could be formed successfully at heating temperatures ranging from 750 to 850°C. The forming failed at lower temperatures due to the limited ductility of the material. At temperatures higher than 900°C, extensive phase transformation of α to β occurred during the heating. During the transfer and forming, the temperature dropped significantly which led to the formation of transformed β, reduction of the formability and subsequent failure. The post-form hardness distribution demonstrated the same tendency as that after uniaxial tensile tests.

Keywords:

titanium alloys, Ti6Al4V, hot stamping, microstructure

Affiliations:
Kopeć M.-IPPT PAN
Wang K.-Imperial College London (GB)
Politis D.J.-Imperial College London (GB)
Wang Y.-Beijing Aeronautical Manufacturing Technology Research Institute (CN)
Wang L.-Imperial College London (GB)
Lin J.-Imperial College London (GB)
9.Kopeć M., Wang K., Wang Y., Wang L., Lin J., Feasibility study of a novel hot stamping process for Ti6Al4V alloy, MATEC Web of Conferences, ISSN: 2261-236X, DOI: 10.1051/matecconf/201819008001, Vol.190, pp.1-5, 2018
Abstract:

To investigate the feasibility of a novel hot stamping process for the Ti6Al4V titanium alloy using low temperature forming tools, mechanical properties of the material were studied using hot tensile tests at a temperature range of 600 - 900°C with a constant strain rate of 1s-1. Hot stamping tests were carried out to verify the feasibility of this technology and identify the forming window for the material. Results show that when the deformation temperature was lower than 700°C, the amount of elongation was less than 20%, and it also had little change with the temperature. However, when the temperature was higher than 700°C, a good ductility of the material can be achieved. During the forming tests, parts failed at lower temperatures (600°C) due to the limited formability and also failed at higher temperatures (950°C) due to the phase transformation. The post-form hardness firstly decreased with the temperature increasing due to recovery and then increased due to the phase transformation. Qualified parts were formed successfully between temperatures of 750 - 850°C, which indicates that this new technology has a great potential in forming titanium alloys sheet components.

Keywords:

titanium, hot stamping, metal forming

Affiliations:
Kopeć M.-IPPT PAN
Wang K.-Imperial College London (GB)
Wang Y.-Beijing Aeronautical Manufacturing Technology Research Institute (CN)
Wang L.-Imperial College London (GB)
Lin J.-Imperial College London (GB)
10.Kukla D., Grzywna P., Kopeć M., Kowalewski Z.L., Assessment of hardened layer thickness for 40HNMA steel using eddy current method, INŻYNIERIA MATERIAŁOWA, ISSN: 0208-6247, DOI: 10.15199/28.2016.5.10, Vol.213, No.5, pp.263-266, 2016
Abstract:

Materials and semi-manufactured products for aviation equipment are usually subjected to increasingly rigorous demands for the quality control. In many cases, like hardened or carburized wheels or rollers assembled in the gear motors, the control procedures enforce necessity of the selective testing of details coming from production lines using destructive techniques. The main aim of diagnostic investigations carrying out on series of final products is to assess qualitatively and quantitatively the layers obtained due to carburizing and induction hardening. Unfortunately, such processes increase the fabrication costs significantly, especially in the case of complex manufacturing technology applied and small-lot production as well. In order to reduce them the attempts for application of non-destructive testing methods are taken for evaluation of either the layers quality or the products subjected to surface treatments. This paper presents the eddy currents method used for the thickness evaluation of the carburized and induction-hardened layers on the basis of the impedance signal variation. The signal was obtained as a result of the so-called ‘lift off’ effect. A methodology for the quantitative thickness evaluation of the carburized and induction-hardened layers has been elaborated under a range of technological parameters. The measurements ranges were defined in the framework of which an identification of the hardened layer was possible using the commercial defectoscope and reference specimens of the fixed thickness. Tests were carried out on specimens made of the ASM6414 steel and subjected subsequently to carburization and induction hardening. The impedance parameters were measured for selected values of frequency. The results were verified on the basis of metallographic investigations as well as the microhardness measurements captured in the form of profiles taken from specimens’ cross-sections of different layer thickness.

Keywords:

eddy current, hardening, carburizing, layers, non-destructive technique

Affiliations:
Kukla D.-IPPT PAN
Grzywna P.-IPPT PAN
Kopeć M.-IPPT PAN
Kowalewski Z.L.-IPPT PAN
11.Kopeć M., Grzywna P., Kukla D., Kowalewski Z.L., Evaluation of the fatigue damage development using ESPI method, INŻYNIERIA MATERIAŁOWA, ISSN: 0208-6247, DOI: 10.15199/28.2016.4.9, Vol.212, No.4, pp.201-205, 2016
Abstract:

Fatigue damage process developing in structural materials under long-term cyclic loading is still an unsolved problem of modern engineering. Attempts to assess a degree of materials degradation under fatigue conditions on the basis of changes in the areas of local strain concentration determined by optical methods can be treated as the promising contemporary research direction of majority of scientific centres in the world. In most cases, fatigue damage has a local character and it is based on damage development leading to generation of cracks appearing around structural defects or geometrical notches. An identification of these areas and their subsequent monitoring requires a full-field displacement measurements performed on the objects surfaces. It seems that modern contemporary optical methods for displacement components measuring on the surfaces of structural elements or tested specimens are suitable for such purpose. Digital Image Correlation (DIC) and Electronic Speckle Pattern Interferometry (ESPI) are nowadays the most widely used testing methods in this area. Both of them enable capturing of displacement and strain components distributions. This paper presents an attempt to use the ESPI method for fatigue damage evaluation and its monitoring on specimens made of the aluminide coated nickel super-alloys. Flat specimens were subjected to cyclic loading. The fatigue tests were interrupted several times in order to perform a static loading during which the optical measurements were carried out. An analysis of the results captured by the ESPI system allowed indication of places of the greatest stress concentration and demonstration of the damage development process as a function of the increasing number of cycles.

Keywords:

fatigue, damage, super-alloy, Electronic Speckle Pattern Interferometry

Affiliations:
Kopeć M.-IPPT PAN
Grzywna P.-IPPT PAN
Kukla D.-IPPT PAN
Kowalewski Z.L.-IPPT PAN

List of chapters in recent monographs
1.
627
Kopeć M., Monograph of 4th European Young Engineers Conference, rozdział: Preparation of abrasion resistant ceramic – intermetallics composites using sintering method with the exothermic reaction, Faculty of Chemical and Process Engineering, Warsaw University of Technology, pp.102-120, 2020

Conference papers
1.Grzywna P., Kukla D., Kowalewski Z.L., Kopeć M., Wyszkowski M., Zastosowanie elektronicznej interferometrii plamkowej do lokalizacji uszkodzeń zmęczeniowych, XXIII Seminarium NIENISZCZĄCE BADANIA MATERIAŁÓW, 2017-03-15/03-17, Zakopane (PL), pp.171-188, 2017
2.Kowalewski Z.L., Dietrich L., Kopeć M., Szymczak T., Grzywna P., Nowoczesne systemy optyczne w badaniach mechanicznych – budowa, działanie, zastosowania, XXII Seminarium NIENISZCZĄCE BADANIA MATERIAŁÓW, 2016-03-16/03-18, Zakopane (PL), pp.5-36, 2016

Conference abstracts
1.Wang K., Kopeć M., Qu H., Wang Y., Wang L., Lin J., Li Z., A unified constitutive model for two-phase titanium alloys under hot stamping condition, ICNFT 2018, 5th International Conference on New Forming Technology, 2018-08-18/08-21, Bremen (DE), pp.1, 2018
2.Grzywna P., Kukla D., Kowalewski Z.L., Kopeć M., Wyszkowski M., Assessment of fatigue damage development using the espi system, 27EMS, Experimental Mechanics of Solids - 27th Symposium, 2016-10-19/10-22, Jachranka (PL), pp.27, 2016
3.Kukla D., Grzywna P., Kopeć M., Kowalewski Z.L., Eddy Current method for thickness assessment of carburized layers, AMT 2016, XXI Physical Metallurgy and Materials Science Conference - Advanced Materials and Technologies, 2016-06-05/06-08, Rawa Mazowiecka (PL), pp.BP7-1-3, 2016
Keywords:

eddy current, hardening, carburizing, layers, non - destructive technique

Affiliations:
Kukla D.-IPPT PAN
Grzywna P.-IPPT PAN
Kopeć M.-IPPT PAN
Kowalewski Z.L.-IPPT PAN
4.Kopeć M., Grzywna P., Kukla D., Kowalewski Z.L., Evaluation of the fatigue damage development using ESPI method, AMT 2016, XXI Physical Metallurgy and Materials Science Conference - Advanced Materials and Technologies, 2016-06-05/06-08, Rawa Mazowiecka (PL), pp.E05-1-4, 2016
Abstract:

Fatigue damage process developing in structural materials under long-term cyclic loading is still an unsolved problem of modern engineering. Attempts to assess a degree of materials degradation under fatigue conditions on the basis of changes in the areas of local strain concentration determined by optical methods can be treated as the promising contemporary research direction of majority of scientific centers in the world. In most cases, fatigue damage has a local character and it is based on damage development leading to generation of cracks appearing around structural defects or geometrical notches. An identification of these areas and their subsequent monitoring requires a full-field displacement measurements performed on the objects surfaces. It seems that modern contemporary optical methods for displacement components measuring on the surfaces of structural elements or tested specimens are suitable for such purpose. Digital Image Correlation (DIC) and Electronic Speckle Pattern Interferometry (ESPI) are nowadays the most widely used testing methods in this area. Both of them enable capturing of displacement and strain components distributions. This paper presents an attempt to use the ESPI method for fatigue damage evaluation and its monitoring on specimens ma de of the aluminide coated nickel super-alloys. Flat specimens were subjected to cyclic loading. The fatigue tests were interrupted several times in order to perform a static loading during which the optical measurements were carried out. An analysis of the results captured by the ESPI system allowed indication of places of the greatest stress concentration and demonstration of the damage development process as a function of the increasing number of cycles.

Keywords:

fatigue, damage, super - alloy, Electronic Speckle Pattern Interferometry

Affiliations:
Kopeć M.-IPPT PAN
Grzywna P.-IPPT PAN
Kukla D.-IPPT PAN
Kowalewski Z.L.-IPPT PAN