The International Symposium on Biomaterials (ISB) provides a multidisciplinary forum for academics, clinicians, researchers, and practicing engineers to exchange innovative ideas and discuss advances in biomaterials, material processing technologies, and their applications in medicine and engineering.

The symposium series was initiated in 2016 through a collaboration between the Department for Orthopaedic Surgery, University Medical Centre Ljubljana, the Institute of Metals and Technology, Ljubljana, and MD-RI Institute for Materials Research in Medicine Ljubljana, with the support of the Dental Department, Faculty of Medicine, University of Ljubljana. Since its inception, the symposium has fostered interdisciplinary dialogue between materials science, biomedical engineering, and clinical medicine.

Previous editions of the symposium were successfully held at the Congress Centre of GH Bernardin in Portorož, Slovenia in 2017, 2018, and 2019. In 2021 the symposium was organized as a hybrid scientific event hosted by the Department for Orthopaedic Surgery, University Medical Centre Ljubljana.

The 6th International Symposium on Biomaterials (6ISB) was organized in 2025 at the Orthopaedic Clinic, University Medical Centre Ljubljana, Zaloška cesta 9, Ljubljana, Slovenia.

The upcoming 7th International Symposium on Biomaterials (7ISB) will again be hosted by the Orthopaedic Clinic, University Medical Centre Ljubljana, bringing together leading international experts in biomaterials, orthopaedics, dentistry, materials science, and biomedical engineering.

The Medical Chamber of Slovenia (ZZS-SMC) endorses the symposium. Participating healthcare professionals including physicians, nurses, and physiotherapists will receive Continuing Medical Education (CME) credit points awarded by the Slovenian Medical Chamber.

The Programme and Organizing Committee, chaired by Assoc. Prof. Dr. Boštjan Kocjančič (Department for Orthopaedic Surgery, University Medical Centre Ljubljana), warmly invite colleagues from academia, clinical practice, and industry to attend the 7th International Symposium on Biomaterials and present their latest research findings and ongoing projects.

The symposium aims to provide a stimulating environment for interdisciplinary exchange, fostering collaboration between life sciences, engineering, clinical research, and industry partners. By bringing together researchers from around the world, the meeting promotes discussion of emerging technologies, innovative biomaterials, and translational approaches that bridge fundamental research with clinical practice.

Topics

Organizers

In the frame of the conference, the 7th International Symposium on Biomaterials on May 22, 2026 is organized by A/Prof. Dr. Boštjan Kocjančič, MD, chair, Prof. dr. Matej Drobnič MD, Prof. dr. Drago Dolinar, MD; Prof. Dr. Monika Jenko, Prof. Dr. Maja Ovsenik, DMD and Prof. Dr. Čedomir Oblak, DMD, members of the scientific and organizing committees.

IMT is the publisher of the scientific journal Materials and Technology (IF 0.60), which publishes original and review scientific papers as well as technology news in theoretical and applied natural sciences and technologies from the fields of metallic and inorganic materials, polymers, vacuum technology, nanomaterials, biomaterials, and surface engineering.

You are also kindly invited to publish your article in the scientific journal Materials and Technologies (MIT), in an issue dedicated to Biomaterials.

REGISTRATION FEE: MD-RI Institue for Materials Research in Medicine, Ljubljana Bohoričeva 5,
TR –SI56 3500 1000 1673 744 (at BKS Bank Ljubljana, Slovenia)

Registration fee includes Program, Abstract booklet, Certificate for the invited lecturers, attendance certificate, and credit points ZZS-MCS
 

Chair: A/Prof. Boštjan Kocjančič, MD

Scientific Committee

• Boštjan Kocjančič, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Matej Drobnič, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Drago Dolinar, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Monika Jenko, MD-RI Institute for Materials Research in Medicine, Ljubljana, Slovenia
• Čedomir Oblak, Faculty of Medicine, University of Ljubljana, Slovenia
• Boris Gašpirc, Faculty of Medicine, University of Ljubljana, Slovenia
• Rok Schara, Faculty of Medicine, University of Ljubljana, Slovenia
• Rok Gašperšič, Faculty of Medicine, University of Ljubljana, Slovenia
• Maja Ovsenik, Faculty of Medicine, University of Ljubljana, Slovenia
• Oskar Zupanc, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Blaž Mavčič, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Rihard Trebše, Orthopaedic Hospital Valdoltra, Ankaran, Slovenia
• Špela Kocjančič, Clinical Department of Intensive Internal Medicine, UMC Ljubljana, Slovenia
• Mojca Debeljak, University Rehabilitation Institute Republic of Slovenia Soča (URI Soča), Ljubljana, Slovenia
• Friderika Kresal, Fizioterapevtika, Ljubljana, Slovenia
• Veronika Kralj Iglič, Faculty of Health Sciences, University of Ljubljana, Slovenia
• Aleš Iglič, Faculty of Electrical Engineering, University of Ljubljana, Slovenia
• Matjaž Godec, Institute of Metals and Technology, Ljubljana, Slovenia

Organizing Committee

• Boštjan Kocjančič, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Drago Dolinar, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Monika Jenko, MD-RI Institute for materials research in medicine, Ljubljana, Slovenia
• Matic Kolar, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Klemen Avsec, Orthopaedic Surgery Dept, UMC Ljubljana, Slovenia
• Rok Ovsenik, Faculty of Medicine, University of Ljubljana
• Mojca Debeljak, University Research Rehabilitation institute URI Soča, Ljubljana, Slovenia
• Sonja Žarković Gjurin, Faculty of Medicine, University of Ljubljana
• Jan Oblak, Faculty of Medicine, University of Ljubljana, Slovenia
• Lea Kolenc, Faculty of Medicine, University of Ljubljana, Slovenia
• Črtomir Donik, Institute of Metals and Technology, Ljubljana, Slovenia
• Ema Kocjančič, Faculty of Medicine, University of Ljubljana
• Igor Potparić, Faculty of Medicine, University of Ljubljana
• Miha Remec, Faculty of Medicine, University of Ljubljana, Slovenia

International Scientific Committee

• Andrej Trampuž, Faculty of Health, School of Clinical Medicine, Brisbane, Australia
• Anouk Galtayries, Paris, Curie Engineering School, France
• Peter Kingshott, Swinburne University of Technology, Australia
• John T. Grant, Dayton University, Ohio, USA
• Ivan Petrov, University of Illinois at Urbana-Champaign, USA
• Sally McArthur, Swinburne University of Technology, Australia
• Christian Teichert, Mountain University Leoben, Austria

Venue

The 7th International Symposium on Biomaterials will be organized in the beautiful Slovenian capital Ljubljana. The symposium will be held at the UNIVERSITY MEDICAL CENTER LJUBLJANA, ORTHOPAEDIC SURGERY DEPARTMENT, LJUBLJANA ZALOŠKA 9, SLOVENIA

»Laser-Textured Surfaces for Enhanced Material Biocompatibility (LTS4EB)«

Abstract:

The LTS4EB project aims to make science more accessible and engaging for the public, leveraging citizen science to advance research and inspire people of all ages—from students to professionals across various fields. The project builds on advancements in biomaterials, using laser technology from the SurfBioApps (ARIS Project) initiative to modify metal surfaces. SurfBioApps brings together experts in materials science, chemistry, biology and medicine. The project focuses on laser surface texturing, a cutting-edge technique that enhances surface properties and biofunctionality with precision, flexibility, and compatibility—without altering bulk properties or relying on chemical additives.

LTS4EB Citizen Science Program Objectives:

• Engage the public in scientific research by involving them in data collection and analysis of laser-textured surfaces.
• Raise awareness of how surface engineering influences biocompatibility.
• Contribute to scientific progress by generating data on the interaction of laser-textured surfaces with biological environments.

InShaPe enables faster, cheaper, and more sustainable technology for manufacturing metal components

IMT is a partner in the InShaPe project, funded by the EU (Grant Agreement No. 101058523). The InShaPe consortium included 11 partners from 8 different countries. The total project value was €6.8 million.

• Project Coordinator: Prof. Katrin Wudy, TUM

• Head of the Slovenian part of the project: Assoc. Prof. Dr. Matjaž Godec, IMT

• Project duration: 01.07.2023 – 30.06.2025

• Project Website

Some Final Conclusions:

Project summary

Properties of common alloys are detrimentally affected by exposure to hydrogen, which lead to hydrogen induced ductile to brittle transition known as hydrogen embrittlement (HE). The magnitude of the deterioration depends on the material and its microstructure, the specific environment, mechanical loading and internal stresses developed during manufacturing. Microstructure of steels, despite having identical chemical composition, deviate significantly when using different processing technologies. The characteristics of laser-based AM processes are high temperature gradients, residual stresses, anisotropy, highly complex and hierarchical microstructures with high dislocation density and chemical inhomogeneity. These specifics can have a critical impact on HE susceptibility. HE can occur through a variety of mechanisms, however, when it comes to AM materials exact underlying mechanisms are still a subject of intensive research and discussion.

The main challenges related to production, storage, transport and use of green hydrogen as a future energy carrier is hydrogen embrittlement of commonly used material - stainless steel, and how HE differs depending on its type, microstructure and production. To address these questions the proposed research project within the area of materials for new energy technologies is primarily focused on defining and understanding the mechanisms of hydrogen embrittlement (HE) in two representative 3D printed stainless steels (austenitic and martensitic) and how they differ as compared to conventionally produced ones.

Project Goals

While green hydrogen represents a key component in a future climate-neutral society, its production, storage, transport and use as a future energy carrier place high demands and safety concerns for suitable materials. This is especially critical when it comes to high-performance additive manufactured (AM) metal alloys, characterized by fine columnar grain microstructure, high dislocation density, micro-segregations, defects and anisotropy. The mechanical properties of metallic materials are detrimentally affected by exposure to hydrogen, which lead to hydrogen embrittlement (HE). The operational conditions in energy production as well in other industries can lead to HE and possible corrosion thus causing sudden and unpredictable failure of structures. HE can occur through a variety of mechanisms, however, exact underlying mechanisms are still being discussed and not understood when it comes to different corrosion resistant stainless steels produced by AM. Characteristics of laser-based AM processes are the repetition of heating, melting, solidification and re-melting with high temperature gradients, which results in high residual stresses, anisotropy, highly complex and hierarchical microstructures with high dislocation density and chemical inhomogeneity. These specifics combined with the type of stainless steel can have a critical impact on HE as well as on its detection.

The main challenges related to production, storage, transport and use of green hydrogen are hydrogen embrittlement and stress corrosion cracking, and how these differ depending on the type and production of stainless steel. To address these challenges directly related to materials for new energy technologies, project focuses on the following goals:

- to analyze behavior of 3D-printed stainless steels in hydrogen-rich environments and assess application capability

- to identify and optimize experimental methods for monitoring of the crack initiation and propagation due to hydrogen embrittlement

- to thoroughly understand the mechanisms of hydrogen embrittlement (HE) in stainless steels and how they differ depending on the stainless steel type and processing route (conventional vs. AM)

- to identify the major parameters affecting HE susceptibility as a function of the microstructure

Methodology and concepts

Project proposal within the field of new energy technologies/materials, combines five activities aimed to identify and understand the mechanisms and susceptibility to hydrogen embrittlement in additively manufactured stainless steels as compared to conventionally produced and depending on the type of stainless steel (microstructure and phases). The project articulates around 5 research axes, detailed below, which lay the foundations for an in-depth investigation of HE mechanisms of AM stainless steels.

Activities will include:

(i) laser-powder-bed-fusion manufacturing, pre- and post-treatment, and establishing the correlation between H-charging parameters and the actual H-concentration for typical stainless steels (austenitic, martensitic), manufactured conventionally and by 3D printing;

(ii) detailed examination and characterization of microstructure and H-related microstructural changes, to qualify and quantify the distribution of the microstructural defects and their evolution in presence of hydrogen and during straining and to address subsequent hydrogen distribution evolution in terms of hydrogen diffusion and trapping (ONH Elemental analyser, ICP-OES, TDS, SEM, FIB-SIMS, FIB-DIC, EBSD, XRD, AES, XPS, TEM, APT);

(iii) testing and identification of H exposure and diffusion on steel properties and behavior under load. Tests will include the determination of common mechanical properties (hardness, toughness, tensile strength) after H-charging, predominantly stress-strain behavior at slow strain rate testing (SSRT) in air and in electrolyte under additional cathodic H-charging, as well as fatigue (bending load) and anti-wear properties (abrasive wear resistance);

(iv) identifying suitability of different methods for monitoring and detection of HE related crack initiation and propagation, as well as properties deterioration (electrochemical noise (EN), acoustic emission (AE), optical monitoring (DIC), Micro-computer-tomography, hydrogen microprint technique), and

(v) defining and understanding HE mechanisms in additively manufactured stainless steels and how they differ as compared to conventional ones. Results of hydrogen distribution/redistribution and HE crack monitoring, post-exposure/post-fracture detailed microstructural examination and characterization together with the understanding of hydrogen diffusion and trapping (distribution) during straining will serve as a basis to define and understand HE mechanisms in the different stainless steels. The general methodology adopted follows the identification of elementary bricks in the potential mechanisms, then addressing the mechanisms of these elementary steps and their kinetics, and progressively complexify the system towards a more representative one (Cartesian approach).

Project team

Project is financed by Slovenian Research and Innovation Agency - ARIS with 2016 hours (C group): 1. 1. 2024 – 31. 12. 2025.

IMT has become a partner of the EU-funded project InShaPe (Nr.: 101058523). The InShaPe consortium includes 11 partners from 8 different countries. The budget of the project is 6.8 Million EUR.

Project Coordinator: Prof. Katrin Wudy, TUM

Project Leader Slovenian part: A/Prof. Dr. Matjaž Godec, IMT

Project duration: 01.07.2023 – 30.06.2025

https://inshape-horizoneurope.eu/

Objective:

The objective of the EU-funded InShaPe project is the flexible adaptation of laser-beam shapes that are tailored to the material/geometry of parts produced by the powder bed fusion of metals using a laser beam (PBF-LB/M) – an additive manufacturing (AM) technology. In the InShaPe project, the optical module and the artificial intelligence (AI) models will be developed to allow a choice of beam shapes, which will also result in a significant increase in build rates. The InShaPe process will enable the AM of high-potential materials that are not printable so far, being characterised by a 7-times-higher build rate, over 50% lower cost and enable truly green manufacturing, characterised by over 60% less energy use and 30% less scrap.

The IMT’s role in the consortium will be the identification of the extent of the possibilities for tailoring the microstructure with beam shape and controlling the mechanical properties. The main task of IMT will be the characterisation of the printed parts and support in analysing the printed industrial cases. IMT will be responsible for in-depth material characterisation; however, the specifics of the printed process (faster process, larger grain size, different cooling rates) will require completely new approaches to the characterization. This means that IMT will not only support other consortium partners with characterisation but will provide R&I-added value through developing/improving current characterisation techniques dedicated to modified laser beam PBF-LB/M parameters. IMT will not just widen the consortium but will bring added value to it by interlinking all the WPs, and due to the systematic control of the printed sample, IMT will reduce the risk of the project underachieving. Understanding and controlling the microstructure and mechanical properties represent a complementary function of IMT, and thus the consortium partners will all receive important feedback through the WPs by carrying out the assigned work more efficiently at reduced risk. IMT will also perform sample post-processing as proper heat treatments. To obtain the maximum properties from Inconel samples and others, it is essential to design the heat-treatment process very accurately (due to the formation of precipitates).

Partners of the project: 

1. Technical University of Munich, Germany (Coordinator)
2. EOS GmbH, Germany
3. Oerlikon AM GmbH, Germany
4. Eindhoven University of Technology, Netherlands
5. SILIOS Technologies, France
6. Beamit Spa, Italy
7. AENIUM Engineering S.L., Spain
8. AMEXCI AB, Sweden
9. Bavarian Research Alliance GmbH, Germany
10. Technion – Israel Institute of Technology, Israel
11. Institute of Metals and Technology, Ljubljana, Slovenia

Three years project started 1.1.2023 – 31.12.2025, Slovenia, Poland and Cheh republic
 

Acronym: NanoPowder
Number of the project: N2-0276
 

prof. dr hab. inż. Jarosław Mizera
WARSAW UNIVERSITY OF TECHNOLOGY
dr Jiri Kubasek
UNIVERSITY OF CHEMISTRY AND TECHNOLOGY, PRAGUE
prof. dr Matjaž Godec
INSTITUTE OF METALS AND TECHNOLOGY
 

Abstract

Oxide dispersion-strengthened (ODS) steels are known because of their superior mechanical properties at high temperatures and increased resistance to neutron irradiation embrittlement which favours them for future applications as a fuel cladding for the next generation nuclear systems and blanket materials for fusion power systems. The scientific goal of the project is to examine whether an ultrasonically gas-atomised precursor steel powder or a steel powder with smart surface oxidation in combination with one of two new consolidation techniques – selective laser melting (SLM) and pulse plasma sintering (PPS) – can impart ODS steel with better performance in extremely harsh, high-temperature conditions. The results will be benchmarked against conventionally produced, mechanically alloyed powder that is consolidated using spark-plasma sintering (SPS).

The current best-performing ODS steels have tensile strengths up to almost 800 MPa at 600 °C, compared to over 1200 MPa at room temperature. The rapid fall of in performance as things get hot can be traced to the uneven distribution and clustering of the dispersed oxides in the microstructure of the consolidated steel component. What our experience with ODS steels teaches us, is that the final properties of the consolidated component are closely connected with the precursor powder and homogenously distributed nanoparticles. It is for this reason that we are focusing our attention on new ways to produce the powders using technologies not available until now. Then, after the powder is consolidated by SPS and PPS we will relate the microstructure, corrosion, and mechanical properties back to the characteristics of the powders. As a proof of concept, we have selected austenitic 316L stainless steel, which has good ductility, workability, and mechanical integrity at high temperature. Y2O3 has been chosen as the nano material to add to the matrix, as it has a higher ultimate tensile strength than other powders and improves oxidation resistance. As the project progresses, and the strengthening mechanisms associated with the nano oxide dispersion will be known, TiB2 nanoparticles (with a higher melting point) will also be employed.

Within the project realization we would like to test the following hypotheses:

1. The application of ultrasonics during the process of gas atomisation will lead to increased dispersion and reduced levels of clustering for Y2O3 and TiB2 that are co-melted with steel in a gas-atomisation process to provide a powder precursor.

2. The surfaces of the gas atomised powders can be partially oxidised in such a way that subsequent consolidation leads to a microstructure with highly dispersed precipitates.

3. The re-melting and/or partial remelting of the powder precursor during consolidation by SLM and PPS leads to microstructural changes compared to the precursor and a re-arrangement of the precipitates and changes to the pattern of clustering.

4. The combination of ultrasonically assisted gas atomisation and SLM and/or PPS can produce ODS steel that performs better in extreme conditions compared to conventionally produced components.

To approach this, the proposed project is divided into 5 working packages, namely: WP1 powder preparation, WP2 component consolidation, WP3 Characterization of the powders and the mechanical and corrosion properties of the components, WP4 Management of the project and WP5 Dissemination, communication, and exploitation. The proposed research project is extremely relevant from the basic research point of view, as it will bring about a much better fundamental understanding of the parameters influencing the manufacture of ODS steels using powder metallurgy routes. SLM is a process that will allow us to re-melt the feedstock powders, build a geometrical structure, during which the rapid melting and solidification will ensure the precipitates will appear. We believe that a very homogeneous distribution of oxides will result from the local mixing of the melt and the subsequent rapid solidification. Moreover, we will learn a great deal more about manufacturing uniform microstructures with SPS and PPS.

1) Scientific goal of the project

The scientific goal of the project is to examine whether an ultrasonically gas-atomised precursor steel powder or a steel powder with smart surface oxidation in combination with one of two new consolidation techniques – selective laser melting (SLM) and pulse plasma sintering (PPS) – can impart oxide-dispersionstrengthened (ODS) steel with better performance in extremely harsh, high-temperature conditions. Our aim is to disperse precipitates of Y2O3 and TiB2 much more evenly in the precursor powders by tuning the ultrasonic parameters of the gas-atomisation process to create the maximum extent of dispersion prior to consolidation. The powders will then be either selectively laser melted or pulse-plasma sintered, before being assessed microstructurally and for their mechanical resilience and resistance to corrosion at very high temperatures. The results will be benchmarked against conventionally produced, mechanically alloyed powder that is consolidated using spark-plasma sintering (SPS).

The project is set up to answer 6 important research questions, listed below:

• To what extent is the application of ultrasonics during the gas atomisation of precursor steel powders containing Y2O3 able to reduce the agglomeration and cohesion of the oxides, leading to greater dispersion of precipitates and reduced levels of precipitate clustering?

• Can the techniques of SLM and PPS maintain the enhanced dispersion during consolidation of the powder and restrict the tendency for the precipitates to migrate and coalesce under the conditions of high temperatures, high thermal gradients and, in the case of PPS, applied pressures.

• To what degree does the re-melting of the gas-atomised powder during the SLM procedure lead to a redistribution of the precipitates in comparison with the partial re-melting of the powder during pulse plasma sintering?

• Is it possible to partially oxidise the surfaces of gas-atomised powder (smart surface oxidation) in such a way that the surface oxides become highly dispersed during subsequent consolidation with SLM and PPS.

• How does the enhanced dispersion and the reduced cluster size impact on the elevated-temperature performance of consolidated components produced by SLM and PPS?

• What are the ultimate limits of dispersion using the combination of ultrasonics during the gas-atomisation procedure, smart surface oxidation, and SLM or PPS?

The project will test 4 hypotheses, listed below:

• The application of ultrasonics during the process of gas atomisation will lead to increased dispersion and reduced levels of clustering for Y2O3 and TiB2 that are co-melted with steel in a gas-atomisation process to provide a powder precursor.

• The surfaces of the gas atomised powders can be partially oxidised in such a way that subsequent

consolidation leads to a microstructure with highly dispersed precipitates.

• The re-melting and/or partial remelting of the powder precursor during consolidation by SLM and PPS leads to microstructural changes compared to the precursor and a re-arrangement of the precipitates and changes to the pattern of clustering.

• The combination of ultrasonically assisted gas atomisation and SLM and/or PPS can produce ODS steel that performs better in extreme conditions compared to conventionally produced components.

2) Significance of the project

State of the art: Powder metallurgy techniques including mechanical alloying followed by hot isostatic pressing, extrusion and rolling are used to form oxide dispersion-strengthened (ODS) steels materials [1–3]. During the mechanical alloying, Y2O3 and Ti are added as dispersed particles and dissolved into the matrix. Subsequent consolidation or heat treatment leads to the formation of complex nanoclusters of Y-Ti-O with a sizes of 2–100 nm. Various powders of austenitic steels including 304, 310, 316 and 316L have been successfully prepared in this way [3,4]. Besides Y-Ti-O, other nanoclusters can be formed. These include Ti-N-, Y-Al-O-, and Y-Si-Ti-Obased phases, where the additional elements are derived from steel (Al, Si, N) or even Y-Zr-O- and Y-Hf-O-based phases, with Hf or Zr added during mechanical alloying [5–7]. Unfortunately, the production of austenitic stainless ODS steel by the presented processes is complicated due to the higher ductility of austenite [8,9]. The production of ODS steels includes long milling times (10s of hours) and demanding compaction techniques like HIP or rolling and extrusion at above 1000°C. As a result, alternatives have been searched for. Techniques like SPS, field-assisted sintering technique (FAST) and additive manufacturing (AM) were investigated [10–14]. It was shown that SPS and FAST can form extremely fine-grained materials with almost theoretical density in tens of minutes [9]. Justification for tackling a specific scientific problem: Many applications are limited by the properties of materials – solar cells, electric vehicles and wind turbines are popular examples – but metallic materials that can remain intact and ensure safety in extreme conditions (particularly high temperatures) are undoubtably an example of where effort should be focused, since breakthroughs in this area will have wide-ranging benefits. We have chosen to tackle this problem because we understand its importance, and because we have the expertise and ideas that can make it happen. The best route is clearly a microstructure that contains a high density of small oxide precipitates (the best candidates being Y2O3 and similar) dispersed in an austenitic matrix, and this is what we plan to achieve. Justification for the pioneering nature of the project: The pioneering nature of the project is to alter powder preparation using various atomization processes, e.g., atomization with or without ultrasounds and adding nano particles during melting, as well as partial oxidation of the atomised powder. The project is strong on innovation, with new technologies, new methods and new ideas for how to achieve specific types of microstructures. The project is also interdisciplinary, bringing together researchers from the fields of metallurgy, physics, and mechanical engineering from three different European countries. The impact of the project results for the development of the research field and scientific discipline:

• The project’s results will lead to breakthroughs in mechanical and corrosion properties by creating a new microstructure for ODS steels prepared by SLM and PPS. The results will provide us with new knowledge about how the microstructure forms in ODS steels.

• The project is about powder preparation and nano oxide precipitations, which is related to new  parameters and conditions of manufacturing, and themicrostructure-dependent properties of ODS steels. The results of the project will enhance our understanding of the complexity of the microstructure-dependent mechanical and corrosion properties of ODS steels and lead to them exhibiting better performance under extreme conditions.

• The project will also impact on educational programmes at the universities of the collaborating partners, where some new courses on steels, powder metallurgy and additive manufacturing will be delivered.

• The results of the proposed project will be disseminated at international conferences which will promote the project’s results and heighten awareness of the research programmes.

3) Concept and work plan

General work plan:

The Project has five WPs and they are schematically shown in Fig. 1. Namely: WP1 Powder preparation, WP2 Component consolidation, WP3 Characterization of the powders and the mechanical and corrosion properties of the components, WP4 Management of the Project and WP5 Dissemination, communication, and exploitation.

Figure 1. General work plan of the project

Specific research goals:

1. To control the microstructure formation and oxide precipitation during consolidation using SLM and PPS, and to benchmark them against Spark-plasma sintering (SPS)

2. To determine how the concentration and dispersion of nanoparticles (Y2O3 and TiB2) will affect the microstructure formation during SLM, SPS and PPS, and learn about the main mechanism of the nano oxides’ formation.

3. To discover which microstructural factors affect the build up of dislocations, and how this impacts on the strengths of the steels manufactured using SLM, SPS and PPS.

4. To reveal the strengthening mechanisms and thermal stability of the material under extreme conditions, particularly high temperatures.

Figure 2. Graphical abstract of the project: WP1, three powder-fabrication routes; WP2, three consolidation steps; WP3, three test regimes.

The project is set up to answer 6 important research questions, listed below:

• To what extent is the application of ultrasonics during the gas atomisation of precursor steel powders containing Y2O3 able to reduce the agglomeration and cohesion of the oxides, leading to greater dispersion of precipitates and reduced levels of precipitate clustering?

• Can the techniques of SLM and PPS maintain the enhanced dispersion during consolidation of the powder and restrict the tendency for the precipitates to migrate and coalesce under the conditions of high temperatures, high thermal gradients and, in the case of PPS, applied pressures.

• To what degree does the re-melting of the gas-atomised powder during the SLM procedure lead to a redistribution of the precipitates in comparison with the partial re-melting of the powder during pulse plasma sintering?

• Is it possible to partially oxidise the surfaces of gas-atomised powder (smart surface oxidation) in such a

way that the surface oxides become highly dispersed during subsequent consolidation with SLM and PPS.

• How does the enhanced dispersion and the reduced cluster size impact on the elevated-temperature performance of consolidated components produced by SLM and PPS?

• What are the ultimate limits of dispersion using the combination of ultrasonics during the gas-atomisation procedure, smart surface oxidation, and SLM or PPS? The project will test 4 hypotheses, listed below:

• The application of ultrasonics during the process of gas atomisation will lead to increased dispersion and reduced levels of clustering for Y2O3 and TiB2 that are co-melted with steel in a gas-atomisation process to provide a powder precursor.

• The surfaces of the gas atomised powders can be partially oxidised in such a way that subsequent consolidation leads to a microstructure with highly dispersed precipitates.

• The re-melting and/or partial remelting of the powder precursor during consolidation by SLM and PPS leads to microstructural changes compared to the precursor and a re-arrangement of the precipitates and changes to the pattern of clustering.

• The combination of ultrasonically assisted gas atomisation and SLM and/or PPS can produce ODS steel that performs better in extreme conditions compared to conventionally produced components

The project is coordinated by the University of Chemistry and Technology in Prague. The project team implementing the project includes researchers from the following institutions:

• Institute of Metals and Technology (IMT)
• University of Chemistry and Technology Prague (UCT)

Project coordinator: Jiří Kubásek

Project leader of Slovenia: 10842 – Matjaž Godec

Amount of effective hours of research work:

Duration of the project: 01.03.2021 – 29.02-2024

Price category: C

Composition of the research group:

Development of advanced bioabsorbable Zn-based materials using powder-metallurgy techniques (cobiss.net)

Efforts to use zinc-based orthopaedic and cardiovascular medical devices have intensified during the past decade. Such materials must possess an excellent combination of mechanical, corrosion and biological properties, which are closely related to the materials’ microstructures. Although various efforts have been made to improve the materials’ performance, conventional methods, including casting, extrusion, rolling or drawing, are normally considered.

The aim of the proposed project is the development of new, bioabsorbable zinc-based alloys containing highly biocompatible magnesium and antibacterial silver, using rarely favoured but newer and very personalized powder-metallurgy techniques, like mechanical alloying, spark plasma sintering, and selective laser sintering/melting.

Detailed observations of the microstructures will be correlated with a variety of material properties, including the generally overlooked creep, fatigue and wear, which bring new knowledge about these relationships and enable the development of advanced bioabsorbable zinc alloys with tailored mechanical, corrosion and biological properties. Those properties are also very important for better mimic of replaced or supportive medical applications in human body.

Processing routes of studies materials

Publications

KUBÁSEK, Jiří, PINC, Jan, HOSOVÁ, Klára, STRAKOVÁ, Markéta, MOLNÁROVÁ, Orsolya, DUCHOŇ, Jan, NEČAS, David, ČAVOJSKÝ, Miroslav, GODEC, Matjaž, PAULIN, Irena, et al. The evolution of microstructure and mechanical properties of Zn-0.8Mg-0.2Sr alloy prepared by casting and extrusion. Journal of alloys and compounds. [Print ed.]. 2022, vol. 906, article 164308, str. 1-14. ISSN 0925-8388. https://www.sciencedirect.com/science/article/pii/S0925838822006995#!, https://dirros.openscience.si/IzpisGradiva.php?id=15057, DOI: 10.1016/j.jallcom.2022.164308. [COBISS.SI-ID 104897795], [JCR, SNIP, WoS do 6. 2. 2023: št. citatov (TC): 5, čistih citatov (CI): 4, čistih citatov na avtorja (CIAu): 0,36, Scopus do 4. 5. 2023: št. citatov (TC): 6, čistih citatov (CI): 5, čistih citatov na avtorja (CIAu): 0,45]
kategorija: 1A1 (Z, A', A1/2); uvrstitev: SCIE, Scopus, MBP (COMPENDEX, INSPEC); tip dela je verificiral OSICT
točke: 13.38, št. avtorjev: 13

Conference contribution

GODEC, Matjaž, PAULIN, Irena, DONIK, Črtomir, KOCIJAN, Aleksandra, VOJTĚCH, Dalibor, KUBÁSEK, Jiří. Development of advanced bioabsorbable Zn-based materials using powder-metallurgy techniques. V: TMS 2023 : 152nd Annual Meeting & Exhibition : March 19-23, 2023, San Diego, California. [S. l.: s.n.], 2023. Str. [1]. https://www.tms.org/AnnualMeeting/TMS2023/Programming/TMS2023_Technical_Program/AnnualMeeting/TMS2023/Programming/TMS2023_Technical_Program.aspx?hkey=e6e2856e-5bc3-4e9b-ba51-03d2e7900b6b. [COBISS.SI-ID 150333443]
kategorija: SU (S)
točke: 0.33, št. avtorjev: 6

The project is coordinated by  the Institute of Metals and Technologies (IMT). The project team that performs the research includes researchers at the following institutions:

• Institute of Metals and Technology (IMT)
• Faculty of Mechanical Engineering, University of Ljubljana (FS UL)
• Biotechnical Faculty, University of Ljubljana (BF UL)

Project leader: 10842 – Matjaž Godec

Amount of effective hours of research work: 7407

Duration of the project: 01.07.2019 – 30.06-2022

Price category: C

Composition of the research group:

Nova biorazgradljiva Fe-Mn zlitina izdelana z konvencionalnim postopkom in s postopkom dodajnih tehnologij s prilagojeno biorazgradljivostjo (cobiss.net)

Biodegradable metallic materials are bioactive materials with a temporary support function and an ability to gradually degrade without a negative impact on the organism. Three groups of materials, Mg-, Zn- and Fe-based alloys, are being developed in this field, but each of them has at least one important drawback. The proposed project deals with developing new, biodegradable, Fe-Mn alloys that possess excellent mechanical properties, making them ideal candidates for applications where long-term support is needed. The main drawback of Fe-Mn alloys is their slow degradation rate. In the project we will focus on the development of Fe-Mn alloys with accelerated biodegradability.

The proposed research project focusses on the development of application-specific, biocompatible, and highly absorbable austenitic Fe-Mn alloys with the aim to tailor their degradation rate. In the conventional metallurgy route we will focus on different approaches, namely chemical alloying, grain-boundary engineering and surface laser texturing. Based on grain-boundary engineering we will increase the grain boundaries that are less corrosion resistant while decreasing the number of highly corrosion resistant, coherent grain boundaries. This can be obtained by a combination of deformation and recrystallization with the aim to increase the number of grain nuclei and decrease their growth rate. The determination of the appropriate parameters for thermomechanical treatment will be one subject of the present project. Parallel to conventional metallurgy route selected as-cast Fe-Mn alloy will be used to produce powders as starting materials in additive manufacturing (AM) route. The AM technology allows us to build porous and hollow structures for cardiovascular stents and also for other orthopaedic implants with a temporary support function and an increased surface area. This allows achieving an increased corrosion rate and superior tissue regeneration. Furthermore, particular alloying, e.g. with silver, allows to achieve anti-bacterial properties. The porous implant structure enables the enhanced ingrowth of tissue cells. Proper SLM processing parameters will be selected to obtain a hierarchical structure with tailored mechanical properties and increased bio-absorbability. To this end we will explore the possibilities to form a dislocation sub-structure with high chemical segregation. Corrosion will be further increased by mixing metal powders with different redox potentials.

The proposed project brings new aspects to the design of bio-absorbable metallic materials for biomedical applications by introducing new production routes, both deviating from the conventional metallurgical approach. On one side, a conventional metallurgical approach is combined with surface laser texturing. On the other side additive manufacturing based on powder bed laser fusion is applied. These approaches open up completely new design possibilities for the development of new bioabsorbing metals that have a great potential to become important for a diversity of biomedical applications. In this way, the proposed research enables completely new research directions based on an interdisciplinary approach combining photonics, materials science and medicine, which is also in line with the European Commission’s strategy. Absorbable and custom-made implants eliminate additional surgical procedures and will, therefore, significantly shorten the total rehabilitation time. Moreover, such implants will contribute to a better quality of the patient’s life, a lower mortality rate and help to reduce additional medical costs.

To achieve the main goal of the research project, i.e., increasing the corrosion rate of Fe-Mn alloys, we propose the following three objectives:

Objective 1: To develop new Fe-Mn alloys by a conventional metallurgical route. We will tailor degradability and optimal mechanical properties through the following three approaches:

• By using alloying elements, such as C, P, S, Cu, Pd and others, that will affect the corrosion by segregation to the grain boundaries or by forming regions with different redox potentials.
• By grain-boundary engineering to increase the grain boundaries that are less corrosion resistant and additionally decreasing the number of grain boundaries that are beneficial for corrosion resistance. This can be obtained by subjecting the steel to severe deformation, so that many dislocations are accumulated, followed by a low-temperature heat treatment for a long time in order to achieve recrystallization, where the majority of the grain boundaries are non-coherent.
• By surface laser texturing, where the interaction between laser radiation and the metallic surface usually results in super-omniphilicity, as a consequence of laser ablation that induces micro-channels and nanostructured metal oxides.

Objective 2: To develop an additive manufacturing (AM) process for Fe-Mn alloys. We will prepare powders from Fe-Mn alloys developed via a conventional metallurgical route by water and gas atomisation. The samples will be produced by selective laser melting (SLM). The developed samples will serve for studying the microstructure and for mechanical testing. Again, three different approaches will be used to increase the degradation rate:

• By choosing the proper SLM processing parameters, a hierarchical structure will be formed with tailored mechanical properties and decreased corrosion resistance. We will explore the possibilities of forming a dislocation sub-structure with high chemical segregation.
• By mixing different nano particles to Fe-Mn powder the conditions for corrosion will be improved by exploiting their different redox potentials. Ag powder will be added to achieve anti-bacterial properties.
• Additionally, AM technology will enable us to increase the surface area that leads to superior bone-tissue regeneration. By "increasing the surface area" we mean changing the surface topography as well as building a 3D object with a porous structure.

Objective 3: The proof of concept. Two items will be produced and tested to show the application potential for further development and reaching a higher TRL. One will be produced from an Fe-Mn alloy using a conventional metallurgical route and the other one will be a 3D-printed (AM) porous Fe-Mn temporary implant that combines the desired mechanical and corrosion properties.

Shema projekta

Publications

MEDE, Tijan, KOCJAN, Andraž, PAULIN, Irena, GODEC, Matjaž. Laser powder-bed fusion of biodegradable Fe–Mn alloy : melt-pool solidifcation. Applied physics. A, Materials science & processing. 2022, vol. 128, article 739, str. 1-13, ilustr. ISSN 0947-8396. https://link.springer.com/journal/339/volumes-and-issues/128-8, DOI: 10.1007/s00339-022-05851-z. [COBISS.SI-ID 117589251], [JCR, SNIP, WoS, Scopus]
kategorija: 1A2 (Z, A1/2); uvrstitev: SCIE, Scopus, MBP (COMPENDEX, INSPEC, METADEX); tip dela je verificiral OSICT
točke: 20.56, št. avtorjev: 4

KRANER, Jakob, MEDVED, Jože, GODEC, Matjaž, PAULIN, Irena. Thermodynamic behavior of Fe-Mn and Fe-Mn-Ag powder mixtures during selective laser melting. Metals. 2021, iss. 2, vol. 11, str. 1-12, ilustr. ISSN 2075-4701. https://www.mdpi.com/2075-4701/11/2/234, DOI: 10.3390/met11020234. [COBISS.SI-ID 49402627], [JCR, SNIP, WoS do 14. 4. 2023: št. citatov (TC): 6, čistih citatov (CI): 5, čistih citatov na avtorja (CIAu): 1,25, Scopus do 8. 4. 2023: št. citatov (TC): 6, čistih citatov (CI): 5, čistih citatov na avtorja (CIAu): 1,25]
kategorija: 1A2 (Z, A1/2); uvrstitev: SCIE, Scopus, MBP (DOAJ, INSPEC, METADEX, PUBMED); tip dela je verificiral OSICT
točke: 23.45, št. avtorjev: 4

DONIK, Črtomir, KRANER, Jakob, KOCIJAN, Aleksandra, PAULIN, Irena, GODEC, Matjaž. Evolution of the epsilon and gama phases in biodegradable Fe-Mn alloys produced using laser powder-bed fusion. Scientific reports. 2021, vol. 11, 10 str., ilustr. ISSN 2045-2322. https://www.nature.com/articles/s41598-021-99042-0, DOI: 10.1038/s41598-021-99042-0. [COBISS.SI-ID 80302083], [JCR, SNIP, WoS do 14. 4. 2023: št. citatov (TC): 6, čistih citatov (CI): 5, čistih citatov na avtorja (CIAu): 1,00, Scopus do 2. 4. 2023: št. citatov (TC): 6, čistih citatov (CI): 5, čistih citatov na avtorja (CIAu): 1,00]
kategorija: 1A1 (Z, A', A1/2); uvrstitev: SCIE, Scopus, MBP (BIOABS, BIOPREW, CAB, DOAJ, GEOREF, MEDLINE, PUBMED, ZR); tip dela je verificiral OSICT
točke: 20, št. avtorjev: 5

Keynote lecture

135. GODEC, Matjaž. Enhanced biodegradability of an Fe-Mn aaloy using a microstructural apporach and by modifying the surface with laser ablation : predavanje na: Global Congress & Expo on Biomaterials, 140th Conference Scientific Federation, May 13-14, 2019, Kuala Lumpur, Malaysia. [COBISS.SI-ID 1581482]
kategorija: SU (S)
točke: 1, št. avtorjev: 1

Invited lectures

134. GODEC, Matjaž, PAULIN, Irena, DONIK, Črtomir, BURJA, Jaka, HOČEVAR, Matej, GREGORČIČ, Peter, KOCIJAN, Aleksandra. Different approaches to achieving biodegradability for the Fe-Mn alloy : TMS 2020, 149th Annual meeting & Exhibition, February 23-27, 2020, San Diego, California, USA. [COBISS.SI-ID 1584810]
kategorija: SU (S)
točke: 0.14, št. avtorjev: 7

38. GODEC, Matjaž, PAULIN, Irena, DONIK, Črtomir, HOČEVAR, Matej, BURJA, Jaka, GREGORČIČ, Peter, KOCIJAN, Aleksandra. Different approaches to achieving biodegradability with an Fe-Mn alloy. V: GODEC, Matjaž (ur.), et al. Program in knjiga povzetkov = Program and book of abstracts. 27. Mednarodna konferenca o materialih in tehnologijah, 16.-18. oktober 2019, Portorož, Slovenija = 27th International Conference on Materials and Technology, 16-18 October 2019, Portorož, Slovenia. Ljubljana: Inštitut za kovinske materiale in tehnologije, 2019. F. 52. ISBN 978-961-94088-3-4. http://mit.imt.si/Revija/izvodi/mit194/BookOfAbstracts_27ICM&T.pdf. [COBISS.SI-ID 1514410]
kategorija: SU (S)
točke: 0.29, št. avtorjev: 7

Lectures

68. ZAEFFERER, Stefan, GODEC, Matjaž, PODGORNIK, Bojan, ŠINKO, Mario, TCHERNYCHOVA, Elena. Hierarchical structure formation of additive manufactured 316L stainless steel using industrial selective laser melting process parameters. V: GODEC, Matjaž (ur.), et al. Program in knjiga povzetkov = Program and book of abstracts. 27. Mednarodna konferenca o materialih in tehnologijah, 16.-18. oktober 2019, Portorož, Slovenija = 27th International Conference on Materials and Technology, 16-18 October 2019, Portorož, Slovenia. Ljubljana: Inštitut za kovinske materiale in tehnologije, 2019. F. 53. ISBN 978-961-94088-3-4. http://mit.imt.si/Revija/izvodi/mit194/BookOfAbstracts_27ICM&T.pdf. [COBISS.SI-ID 1517482]
kategorija: SU (S)
točke: 0.4, št. avtorjev: 5

63. KRANER, Jakob, MEDVED, Jože, GODEC, Matjaž, PAULIN, Irena. Characterization of metal powders. V: GODEC, Matjaž (ur.), et al. Program in knjiga povzetkov = Program and book of abstracts. 27. Mednarodna konferenca o materialih in tehnologijah, 16.-18. oktober 2019, Portorož, Slovenija = 27th International Conference on Materials and Technology, 16-18 October 2019, Portorož, Slovenia. Ljubljana: Inštitut za kovinske materiale in tehnologije, 2019. F. 96. ISBN 978-961-94088-3-4. [COBISS.SI-ID 1836127]
kategorija: SU (S)
točke: 0.5, št. avtorjev: 4

Conference contibution

69. DONIK, Črtomir, PAULIN, Irena, KOCIJAN, Aleksandra, GODEC, Matjaž. Impact of different chemical composition on biodegradablility of Fe-Mn alloys. V: GODEC, Matjaž (ur.), et al. Program in knjiga povzetkov = Program and book of abstracts. 27. Mednarodna konferenca o materialih in tehnologijah, 16.-18. oktober 2019, Portorož, Slovenija = 27th International Conference on Materials and Technology, 16-18 October 2019, Portorož, Slovenia. Ljubljana: Inštitut za kovinske materiale in tehnologije, 2019. F. 44. ISBN 978-961-94088-3-4. http://mit.imt.si/Revija/izvodi/mit194/BookOfAbstracts_27ICM&T.pdf. [COBISS.SI-ID 1517226]
kategorija: SU (S)
točke: 0.5, št. avtorjev: 4