


Badania
Pracownicy Laboratorium uczestniczą w projektach i pracach naukowo-badawczych dotyczących materiałów metalowych, polimerowych, ceramicznych i kompozytowych w szerokim zakresie ich zastosowań od przemysłu motoryzacyjnego do biomateriałów wykorzystywanych w ochronie życia i zdrowia.
Nasze badania dotyczą m.in. takich zagadnień jak:
- biomateriały polimerowe w rekonstrukcjach tkanek;
- własności tytanu i jego stopów wytwarzanych technologią SLM (Selective Laser Melting);
- struktura i własności węglików spiekanych;
- nanokrystaliczne powłoki AlTiSiN technologią CAE-LARC (Cathodic Arc Evaporation – LAteral Rotating Cathodes);
Najnowsze publikacje naukowe dostępne są w zakładce -> Publikacje
Effect od a manganese content on the kinetics of nanobainite formation in medium-Mn steels with retained austenite
Medium manganese steels for the automotive industry were invented as a compromise between price and mechanical properties. They are characterized by a manganese content from 3 to 12 wt.% and the presence of retained austenite in the microstructure. During deformation, this austenite is transformed into strain-induced martensite locally increasing steel’s strength, which leads to better formability of the sheet material. The use of bainite in the microstructure allows for better plastic properties, which is related to its lower hardness compared to martensite.
In the present work, an attempt was made to create a nanobainitic structure in medium-manganese steels (containing 3 and 4 wt.% of Mn) with retained austenite, and to determine the influence of Mn content on the bainitic transformation kinetics under various heat treatment conditions. In order to reduce the Ms temperature, intercritical annealing was used in the range of 780 – 860 °C, which allowed for subsequent isothermal holding at temperatures in the range of 200 – 300 °C. The bainite transformation kinetics and the thermal stability of austenite were determined by the use of dilatometry. The identification of the phases were done using SEM and EBSD analyses of the samples after the two-step heat treatment.
Badania wykonali: dr inż. Mateusz Morawiec (Politechnika Sląska, Laboratorium Badania Materiałów) i prof. dr hab. inż. Adam Grajcar (Politechnika Sląska, Katedra Materiałów Inżynierskich i Biomedycznych).
Praca była współfinansowana przez Narodowe Centrum Nauki, w ramach grantu nr 2021/41/N/ST8/03371.
The theoretical and experimental analysis of nanobainite formation in a medium-Mn steel by the use of double-step heat treatment
The dynamic development of high-strength steels for the automotive industry requires to develop new types of steel by modifying the chemical composition or through new types of heat treatment, allowing for obtaining higher mechanical properties, without the use of expensive alloying elements or excessive consumption of natural resources. Due to the desire to limit the use of ferrous alloys in steel production as much as possible and to increase the use of circulating scrap, a good direction is to modify the currently used heat or thermomechanical treatments of steel [1]. One way to change the properties of a material is to create a nanostructure in it, which, due to its small grain size, has higher mechanical properties while maintaining the same chemical composition [2]. However, sometimes this is associated with the need to develop a multi-step heat treatment. The work is focused on a steel containing 3.6% Mn and developing a novel heat treatment consisting of the intercritical annealing in a 780–860°C range, allowing for lowering the martensitic start temperature to the range of 200-300 °C, where it is possible to produce nanobainite. In order to initially determine heat treatment parameters, JMatPro software was used and the verification of these parameters was carried out using dilatomatric tests, allowing the determination of characteristic temperatures and the kinetics of bainitic transformation.
Badania wykonali: dr inż. Mateusz Morawiec (Politechnika Sląska, Laboratorium Badania Materiałów) i prof. dr hab. inż. Adam Grajcar (Politechnika Sląska, Katedra Materiałów Inżynierskich i Biomedycznych).
Praca była współfinansowana przez Narodowe Centrum Nauki, w ramach grantu nr 2021/41/N/ST8/03371.
Design and dilatometric processing of nanobainitic structures in Al-alloyed 3Mn multiphase steel
The purpose of the research was to determine the possibility of nanobainite formation in the hot-rolled 3Mn steel with a high aluminium content. Such microstructure design could increase the strength of the steel, keeping moderate plasticity (better than in case of martensitic steels). The main issue of such approach is that the nanobainite forms at a temperature below 300 °C. Such temperature is lower than martensite start temperature (Ms) of the alloy. This results in a need to use a two-step heat treatment composed of intercritical annealing and isothermal bainite holding. The first step is necessary to control the Ms temperature by carbon and manganese diffusion into the austenite. The purpose of the second step is to transform the austenite into nanobainite. The presented results of the dilatometric, microstructural and hardness analyses are carried out in the intercritical annealing temperature range of 760 ÷ 870 °C, which ensures the Ms temperature in the range of 200 ÷ 300 °C. The dilatometric results confirms the formation of bainite in this temperature range. The final cooling shows that the austenite remaining in the microstructure is thermodynamically stable to room temperature.
Badania wykonali: dr inż. Mateusz Morawiec i prof. dr hab. inż. Adam Grajcar (Politechnika Sląska, Katedra Materiałów Inżynierskich i Biomedycznych).
Praca była współfinansowana przez Narodowe Centrum Nauki, w ramach grantu nr 2021/41/N/ST8/03371
Nanobainite formation in high-Al medium-Mn steels: thermodynamic approach
In the present work, it was aimed to produce nanobainite in the microstructure of 0.17C-(3.1-3.6)Mn-1.6Al-0.2Si-0.2Mo-0.04Nb type steels, which is characterized by high strength and better plasticity than martensite. However, due to the relatively high martensite start temperature (Ms) temperature, a two-stage heat treatment was proposed to reduce this temperature and produce the nanobainite. The reduction of the Ms temperature is important because nanobainite is formed at relatively low temperatures (200-300 °C). The presence of nanobainite together with retained austenite and some fraction of ferrite could allow for the good combination of mechanical properties.
Nanobainite ensures high strength and moderate elongation, whereas retained austenite allows for greater elongation. The ferrite occurrence is required to reduce the Ms temperature and to increase elongation, unfortunately at the expense of strength. Therefore, it is important to develop parameters that allow the Ms temperature to be reduced with the lowest possible ferrite amount.
Badania wykonali: mgr inż. Mateusz Morawiec, dr inż. Jaropsław Opara (Łukasiewicz Research Network) i prof. dr hab. inż. Adam Grajcar (Politechnika Sląska, Katedra Materiałów Inżynierskich i Biomedycznych).
Praca była współfinansowana przez Narodowe Centrum Nauki, w ramach grantu nr 2021/41/N/ST8/03371.
Badania struktury krystalicznej i elektronowej nanocząstek typu core-shell NaYF4 z domieszkami lantanowców
Celem prowadzonych badań było zsyntezowanie próbek rdzeń@płaszcz, z luminescencyjnym rdzeniem i pasywnym płaszczem. Badano wpływ grubości płaszcza na własności emisyjne materiału i jego przydatność do tzw. testów immunoenzymatycznych FRET. Skład rdzenia był taki sam dla wszystkich próbek w danej serii (NaYF4 zawierający 2%Tm i 48% Yb oraz NaYF4 zawierający 8%Tm). Rdzeń był następnie pokrywany warstwą płaszcza (NaYF4 bez domieszek jonów) o różnej grubości. Mikroskopia elektronowa umożliwiła określenie grubości płaszcza w kolejnych próbkach i potwierdzenie ich składu chemicznego (analizy punktowe z użyciem spektrometrii dyspersji energii charakterystycznego promieniowania rentgenowskiego EDS i mapowanie rozkładu pierwiastków chemicznych) oraz obrazowanie i potwierdzenie składu fazowego (HR STEM, SAED).
Badania wykonała Pani dr hab. inż. Mirosława Pawlyta, prof. PŚ
Współpraca naukowa z:
Instytut Niskich Temperatur i Badań Strukturalnych im. Włodzimierza Trzebiatowskiego Polskiej Akademii Nauk, Oddział Spektroskopii Optycznej, Grupa Spektroskopii Stanów Wzbudzonych, ul. Okólna 2, 50-422 Wrocław, Polska
prof. dr hab. Artur Bednarkiewicz, dr Katarzyna Prorok, mgr Magdalena Dudek