Invited lectures

Lech Pawłowski

Institut de Recherche sur les Céramiques (IRCER), University of Limoges, 12, rue Atlantis, 87068 Limoges, France

With presentation: Technologies of thermal spraying and laser treatment for additive manufacturing

Abstract: Additive manufacturing (AM) of objects is a rapidly growing field of science and technology. The growth includes the techniques of coatings deposition such as thermal spraying. In particular the techniques enabling rapid growth of coatings such as cold gas spray method (CGSM), high velocity oxy-fuel (HVOF) deposition, detonation spraying (D-gun) or arc spraying (AS). These techniques are presented and briefly discussed from the point of view of their utility in additive manufacturing. Laser treatment can also be an important part of such manufacturing as e.g. technology of selective laser melting (SLM). Consequently, the lasers used in this technology are also reviewed and the principal mechanisms of interaction between laser beams and surface of liquids and solids are shortly described. The recent studies concerning the application of the technologies including thermal spraying and laser treatment are reviewed and the industrial applications are shown.

Lech Pawłowski´s professional career has been bounded since 1973 to thermal spraying. In this field he has pursued activity as researcher, educator, development engineer and manager. This career can be categorized in three stages: (i) his own education and formation; (ii) industrial activity; (iii) education of others and individual research. The education started with diploma of electronic engineer, followed by the PhD and DSc studies and a period of “catching up the level in materials science” in an Australian university (Monash in Melbourne). The stage of practical application of scientific ideas came when working as a project manager in German industry. The present period of education and formation of others started in 1995 at nomination as a university professor. Then, he started to realize the research in his own way. This way is characterized by a practical character (studies of electronic emitters, biomaterials…) being accompanied by understanding the fundaments of coating’s formation process.
He has authored or co-authored of 143 papers, 3 books and 3 chapters of books. The papers were cited more than 4800 times and the Hirsch index is equal to h=34 (number of h papers cited at least h times) after Scopus database checked on 17 November 2022. He is a member of editorial board of two journals: Surface and Coatings Technology (Elsevier) and Coatings (MDPI).

Sergi Dosta

Materials Science & Surface Engineering, ,

With presentation: Basic principles of the Cold Spray Technology

Abstract: Basic principles of the Cold Spray Technology will be explained in this talk. The Cold Spray is a solid state process that will allow to grow thick structures without delamination or decohesion. The effect of main parameters influencing the process to build up this kind of coatings will be shown. Process gas, pressure or temperature, but also distance, surface activation or angle of deposition are some of the items that will be described.

Sergi Dosta is President of the ETSA (European Thermal Spray Association) since June 2022, and professor of the Department of Materials Science and Physical Chemistry at Universitat de Barcelona since 2007, he has a long teaching and research career. He has published more than 130 works in high-level and internationally prestigious journals in the field and with an h-index of 31 according to the SCOPUS database, with more than 2700 citations.
He has a lot of experience in thermal spray field, and specifically in Cold Gas Spray technology, collaborating with national and international research centres and companies. He has also participated in scientific committees of numerous and prestigious conferences in his research area such as the ITSC, SMT, Materiais, Tratermat, among others.

Jan Čížek

Department of Materials Engineering, Institute of Plasma Physics of the Czech Academy of Sciences, Prague, Czech Republic

With presentation: Protective CS deposits in nuclear sector: W and W-Cr for fusion + Fe/Mo for Gen IV fission

Abstract: Harnessing nuclear fusion is a challenging task, in particular because of the demands on the used materials. In tokamaks, our future energy sources, the inner-most chambers will be subjected to extreme thermo-mechanical or radiation conditions (such as temperatures ~10^8 K) and required to sustain functionality for prolonged periods of time. To ensure this, many of the plasma facing components are to be coated with protective coatings. At the moment, pure W or W-Cr-based alloys are the prime candidates. So far, the attempts for W-based coatings formation were limited due to oxidation, high porosity, insufficient adhesion, high specific surface, or even insufficient thickness below 10 µm. Cold spraying seems a promising technology for the task. Here we demonstrate a successful fabrication of thick W, W-Cr and W-Cr-Ti coatings prepared without oxidation of the metals. For the first time in history, a deposition of 80 µm-thick coating of pure W was achieved.
Fission: Lead, lead-bismuth, or lead-lithium are candidate materials for liquid metal-based cooling media in the new generation of nuclear fission reactors. Despite the many benefits they offer, they also trigger a severe degradation of the structural steels in direct contact. One of the solutions to minimize the damage could be a deposition of thick, long-life protective coatings onto the steel surfaces. In our opening study, we have employed CS and RF-ICP technologies to deposit Mo and Fe coatings onto ferritic-martensitic type 9% Cr Eurofer-97 steel and its ODS variant, and tested them in the liquid PbLi environment at 600 °C for up to 1000 h. The results have shown that all coatings prevented the dissolution of the steels. On top of that, the Fe coatings also completely prevented the PbLi penetration, thereby providing a promising complex resistance to the corrosive medium.

After graduating from Czech Technical University in Prague, Jan Čížek has joined Nanyang Technological University in Singapore, where he had obtained his PhD in surface modification of biocomponents. After 8 Asian years, he returned home to join Brno University of Technology. In 2017, he joined Institute of Plasma Physics in Prague, where he happily plans to perish.
He is an active member of several international societies, major conferences committees, and serves as a guest editor and a reviewer to over 40 international journals. He tortures students at 2 different universities. His research interests are thermal spray technologies, in particular cold spray and plasma spray, as well as biomaterials, high-entropy alloys, and plasma facing materials.
He is an avid backpack-traveler, mountain hiker, lost in countless jungles and deserts, enthusiastic sportsman and sports supporter, motorbike rider, scuba diver, mountain climber, amateur theater actor, and photographer. He is really terrible at singing.

Markus Brotsack

Impact Innovations GmbH, Rattenkirchen, Germany

With presentation: Cold Spray Additive Manufacturing (CSAM) of space and aviation components

Abstract: In space and aviation industry, materials with high strength to weight ratios along with properties such as excellent tensile strength, fatigue strength and fracture toughness in combination with low specific weight are needed. However, there are specific parts such as launcher propulsion system components, where the focus’ of the properties are on heat conductivity, mechanical strength at elevated temperatures and dissimilar material combinations.
The manufacturing of highly complex components such as combustion chambers is straight forward by using cold spray process. While using Cold Spray Additive Manufacturing (CSAM) technology, it is possible to create a combustion chamber (used materials: high-strength Cu alloy and for outer jacket Inconel) without restrictions in terms of size and with properties that are superior to the AM process. Looking at the deposition rates of about 10 kg/h for Cu-alloy and 6.7 kg/h for Inconel the process is very economic, concerning manufacturing speed. Additionally, the CSAM process is known for very high deposition efficiencies (DE), in the discussed example values of 99% for Cu-alloy and of 79% for Inconel were measured and this also reduces the production costs compared to other AM technologies significantly.
Cold spraying is also a cost-effective technique for repairing and restoring industrial application products to refurbish and reuse the damaged parts. The properties of cold spraying for the deposition of materials in the solid state make it an attractive method for repairing / restoration, while maintaining the unique properties of the original components or improving the properties of the repaired components by depositing essential materials, especially with regards to corrosion and wear resistance.

Markus Brotsack can look back to six years in metal additive manufacturing industry. Markus did collect experiences in laser powder bed fusion and cold spray technology. Now he is working in the sales department for Impact Innovations GmbH, the market and innovation leader in cold spray equipment. His focus in general is on Cold Spray Additive Manufacturing (CSAM) and in particular on space and aerospace applications, as well as Cold Spray applications in Energy and Power generation. With laser powder bed fusion technology Markus was mainly focusing on applications for precious metals for jewellery and in industry. Before that Markus covered different positions as R&D, field application and sales engineer for different high-tech companies in the field of semiconductor manufacturing. Markus holds a degree in Physics and MBA International Marketing. Markus’ master thesis in physics was on the topic of the spectroscopy of huge giant stars. His master thesis during his MBA studies was a market and potential study for nanoimprint technology for semiconductor applications.

Thomas Lindner

Chemnitz University of Technology, Materials and Surface Engineering, Germany

With presentation: Surface functionalization in selective laser melted 17-4 PH by plasma polishing and interstitial diffusion hardening

Abstract: Developments in processing technology and feedstocks are key drivers for new product innovations in the field of additive manufacturing. In the area of complex and filigree geometries, additive manufacturing technologies are often superior to conventional processes. Selective laser melting (SLM) as powder bed process allows components of different scales to be manufactured by variation of the grain size range of the feedstocks. However, the surface quality achieved is a critical factor. The powders used as feedstock fundamentally limit the surface quality of SLM components. Particle contamination on the surfaces of the parts can remain rounded or agglomerated contributing to a very rough surface at the microscale. Furthermore, the manufacturing advantages of a closed component design lead to limitations in the mechanical finishing process, especially regarding undercuts and cavities. In contrast, surface quality has gain an increasing role. In addition to corrosion protection requirements, demands for wear resistance get more and more frequent. This study deals with the development of a process chain for the surface functionalization of selective laser melted 17-4 PH by plasma polishing and interstitial diffusion hardening. In this context, both the leveling of the surface topography and the development of graded coating properties are of particular interest. While plasma polishing offers appropriate potential for the formation of smooth surfaces, low-temperature diffusion processes can increase wear resistance while avoiding component distortion as a result of heat treatment. Both individual technologies each promise high application potential, which can be exploited to the optimum through the development of a process chain.

After graduating from TU Bergakademie Freiberg, Thomas Lindner went to Chemnitz where he obtained his PhD surface hardening of austenitic coatings. He is group leader of the Thermal Coating and Thermochemical Processes department. Both the development of new coating materials and the exploration of synergy effects through the process combination of different surface technologies represent important research priorities. He led a junior research group on high-entropy alloys for surface engineering. After several national projects and industry collaborations, he is currently involved in two international joint projects. He authored and co-authored over 50 papers (H-index = 13).
He lives just a few minutes from the Czech border. Nevertheless, he just met and fell in love with Olomoucké tvarůžky last year at an project meeting in Olomouc. After a failed attempt to visit the highest church tower in the Czech Republic, he is optimistic that this will succeed latest in June 2023.

Shrikant Joshi

University West, Trollhättan, Sweden

With presentation: High-Velocity Air-Fuel Deposition of Ti6Al4V: Microstructure, Properties and Prospects for Repair Applications

Abstract: Increasing deployment of light materials such as Titanium alloys is consistent with the ambition of the aerospace industry worldwide to reduce total weight and improve engine efficiency to move towards the common objective of achieving sustainability. The growing emphasis on developing improved approaches for repair of damaged parts to delay/avoid replacement with new ones is another step in the direction of attaining the sustainability goals. Several different techniques have so far been explored for repairing conventional aero-engine components, but their application has been limited due to one or more of varied factors such as high residual stresses, excessive heat input, distortion of components, high costs etc. Among the thermal spray methods, high-velocity oxy-fuel (HVOF) spraying has been utilized but found to lead to in-flight oxidation of sensitive materials. This provides the motivation to investigate a comparatively lower temperature process like high velocity air fuel (HVAF) spraying for potential repair of components manufactured from temperature-sensitive materials like Ti6Al4V. This paper will discuss the influence of HVAF process variables on the porosity, microstructure, oxygen pickup and microhardness of as-sprayed Ti6Al4V coatings. In addition, results revealing the influence of post-treatments (both heat treatment and HIP) on the above characteristics and wear behaviour of Ti6Al4V coatings will also be presented. This is expected to provide useful insights into the prospects of utilizing HVAF for repair of Ti alloy components.

Prof. Shrikant Joshi is currently a Professor in the Department of Engineering Science at University West in Trollhättan, Sweden. He has nearly 30 years of experience in areas spanning Surface Engineering, Laser Materials Processing and now also Additive Manufacturing. He is a Chemical Engineer by academic training, having obtained his M.S. and Ph.D. degrees from the Rensselaer Polytechnic Institute and University of Idaho, respectively, in USA. Prior to moving to Sweden, he has had long stints as a Scientist at a couple of premier federally funded materials’ research laboratories in India. His current areas of research are high velocity air fuel (HVAF) spraying, solution & solution-powder hybrid thermal spraying and additive manufacturing. His work has led to many industrial applications, over a dozen patent submissions and more than 200 publications in peer-reviewed journals. He is a Fellow of ASM International, the Institute of Materials, Minerals & Mining (IoM3) and the Indian National Academy of Engineering.

Šárka Houdková

Research and Testing institute Plzeň, Pilsen, Czech Republic

With presentation: DePriSS project – Development of “3D print-thermal spray” systems for applications with dynamic and impact loading

Abstract: Additive technologies have potential to produce light and complex-shaped components. However, required service life and reliability under different load modes has to be ensured. Cyclic and dynamic loading can be considered critical. Components surfaces need to be protected against wear and corrosion. For various reasons fatigue strength and service life may be reduced. Main objective of project DePriSS is the development of 3D print-thermal spray systems resistant against wear and corrosion. Optimization of coatings composition and process parameters will be done. Methodologies for evaluating the response to cyclic and dynamic loads of 3D printed components, coatings themselves and their combinations will be developed and validated. Such combination enables to exploit advantages of 3D printing with benefits provided by thermal spraying. The results will have an impact on extension of both additive technologies into wider range of application, including power, aerospace, automotive, civil engineering etc.

Šárka Houdková finished her PhD studies in 2004, focusing on the evaluation of mechanical properties of thermally sprayed coatings. Since then, he has been researching and developing surface layers, applied namely by thermal spraying and laser cladding technologies. The main focus of her professional work is focused on coatings resistant to wear, corrosion and oxidation. She is the author and co-author of more than 40 journal publications and many conference papers (h-index=15). She works in Research and Testing institute in Pilsen for more than 23 years, focusing on the applied research and development in the field of thermal spraying. She is also participating in the leading of MSc and PhD students on in research activities of University of West Bohemia in Pilsen, where she focused on the application of laser technologies in surface engineering. She is a member of the scientific committees of several conferences and represents the Czech Republic in the European Thermal Spray Association, where she acts as a vice-president.

Lutz-Michael Berger

Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Dresden, Germany

With presentation: Strategies for replacement of WC-Co in thermal spray

Abstract: This year the 100th anniversary of the invention of WC-Co is celebrated. It is one of the most successful composite materials ever and is applied as a tool and wear protection material, as well as a coating material. The presentation attempts to explain the reason for this success, including the differences between the requirements to sintered bulk and thermally sprayed WC-Co. As thermally sprayed coatings are serving more often at high temperature and in corrosive environments, Cr3C2-NiCr is established as a second successful composite for thermal spray applicat. However, there a new challenges as the replacement of Co as the binder is widely discussed, due to health and environmental endangering, but also increasingly as a critical raw material. At the same time, tungsten entered the group of critical raw materials as well. By this reason different possible strategies for WC-Co replacement (“partial” replacement of the binder or full replacement of the composite) will be discussed.

Lutz-Michael Berger Berger graduated in Ceramic Engineering at the Moscow Institute of Chemical Technology “D.I.Mendeleev” in 1985 and received a Ph.D. in Environmental Engineering (Material Recycling) at the same Institute in 1989. He started to work at the Institute of Solid State Physics and Material Research of the former East German Academy of Science in Dresden in 1989, and worked as a post-doc at the Institute for Chemical Technology of Inorganic Materials at Vienna University of Technology in 1991. After transformation of East German science he was working 1992-2001 at Fraunhofer IKTS in Dresden, 2002-2014 at Fraunhofer IWS in Dresden and since 2015 again at Fraunhofer IKTS. In 2015 he defended his habilitation at Vienna University of Technology. Currently he is a Senior Scientist at Fraunhofer IKTS.
The main scientific topics are oxides and hardmetals for surface engineering, coating characterization, and synthesis of hard materials (carbides, carbonitrides).
He has authored or co-authored about 100 peer-reviewed papers / book chapters, about 150 contributions to conference proceedings, and about 15 patents, granted in part in Europe, USA, and Japan. The Hirsch index is h=33 (Scopus database).

Ivana Zetková

Regional Technological Institut, Faculty of Mechanical Engeneering, University of West Bohemia, Pilsen, Czech Republic

With presentation: Residual stress in printed components

Abstract: The contribution deals with improving of residual stress in printed maraging steel X3NiCoMoTi18-9-5 by process parameters change. In general, printed components arise the undesirable tensile residual stress which cause deformations and cracks. There were tested different parameter sets for stress reducing. Minimizing tensile residual stresses contributes to increasing the reliability of printed components and reducing the need for post-processing. Primary drilling method was use for residual stress evaluation. The optimized parameter set was compared with standard parameter set from the view of fatigue life testing, material analysis and surface quality.

Ivana Zetková finished her PhD studies in 2017, focusing on metal additive manufacturing of maraging steel C300. Since 2010, she has been working at Department of Machining Technology (Faculty of Mechanical engeneering) on University of West Bohemia in Pilsen. She is leading of Bc, MSc students and is participating on research activities of PhD students. This is connected with hers reseach activities in Regional Technological Institut. Since 2013, she has been focusing on metal 3D printing. She is participating in projects and publication activities (h-index=7) in this topic.

Adam Niesłony

Department of Mechanics and Machine Design, Faculty of Mechanical Engineering, Opole University of Technology, Opole, Poland

With presentation: Fatigue testing of coated components

Abstract: Thermal sprayed coatings are widely used to enhance the mechanical properties of machine elements and constructions, particularly to increase their resistance to external factors such as wear, corrosion, and fatigue. However, the application technology may affect the strength properties of the base material itself, which raises concerns about the integrity of the final product. This paper aims to investigate whether the application of thermally sprayed coatings on metallic materials can alter their strength properties and, consequently, how it may affect their fatigue strength. Moreover, the paper addresses the challenge of determining failure mechanisms in thermally sprayed parts, which can be complicated due to the presence of additional layer of the coating. For instance, the failure can be initiated by the appearance of a crack on the coating or a crack in the base material, and this can affect the overall performance and reliability of the part. This paper discusses various factors that should be taken into account when evaluating the fatigue strength of thermally sprayed parts and proposes guidelines to handle them effectively. The results presented in this paper can help engineers and researchers to optimize the design and manufacturing process of thermally sprayed parts, thus improving their performance and reliability.

Prof. Adam Niesłony has been a distinguished scientist and academic teacher at the Opole University of Technology in Poland since 2003. With a deep expertise in the field of materials fatigue, his research work focuses on the strength of machine parts, durability of machine elements, and dynamics of structures.
Prof. Niesłony contributions to the field of materials engineering are significant and he is widely recognized as a co-author of a novel method for determining material fatigue constants from strain tests, as well as the author of the multiaxial fatigue failure criterion that is dedicated to the frequency domain approach.
He is also enthusiastic about collaborating with colleagues from the industry and contributing to the transfer of intellectual property. Prof. Niesłony dedication to developing future scholars in the field is evident through his supervision of six doctoral dissertations.
In addition to his research accomplishments, Prof. Niesłony is an accomplished educator. He is responsible for teaching courses on fatigue of materials and practical FEM analyses, which undoubtedly enhances the knowledge and skills of his students. We are excited to have Prof. Niesłony as a invited lecturer at our workshop, and look forward to learning from his insights.

Giovanni Bolelli

The Department of Engineering “Enzo Ferrari” of the University of Modena and Reggio Emilia, Italy

With presentation: Preparation of selective laser melted surfaces for thermal spray coatings

Giovanni Bolelli graduated in Materials Engineering at the University of Modena and Reggio Emilia in 2003 and received a Ph.D. in Materials Engineering at the same University in 2008. Since 18/11/2022, he is Associate Professor of Materials Science and Technology at the Department of Engineering “Enzo Ferrari” of the University of Modena and Reggio Emilia, and acts as Lead Editor of the Journal of Thermal Spray Technology since January 2023. His research activity primarily focuses on protective coatings deposited by thermal spray processes, including metal, hardmetal, ceramic and composite coatings for sliding and abrasive wear protection (from room temperature up to elevated temperatures) and for corrosion protection. Experimental characterizations are coupled to thermo-mechanical finite element modelling of coating performance and of deposition processes. Other research topics include oxidation and hot-corrosion protection, and bioactive coatings for prosthetic implant applications. The research activity also extends to other surface engineering techniques, such as chemical and physical vapour deposition (PVD, CVD) and pack cementation. Most of these activities are carried out in collaboration with national and international research institutes and companies.

Leszek Łatka

Wrocław University of Science and Technology, Poland

With presentation: Tribological performance of the cermet coatings manufactured by HVOF on the magnesium alloy substrate

Abstract: In the field of surface engineering, thermal spraying is very wide adopted in many branches of the industry. The main reasons of such situation are its flexibility as well as cost effectiveness. Among others, High Velocity Oxy Fuel (HVOF) technique is dedicated for spraying hardmetal and cermet coatings, especially for wear, cavitation erosion and corrosion resistance. Such type of coating could be a promising candidate as protective layer for magnesium alloys elements. These materials need a strong improvement in the corrosion protection as well as on the field of wear resistance in order to be widely used in the industry. In this work, different WC-based coatings, namely: (i) WC-Co, (ii) WC-Co-Cr and (iii) WC-Cr3C2-Ni manufactured by HVOF spraying, were investigated. The form of all feedstock materials was agglomerated and sintered powder. Cermet coatings microstructure discontinuities such as pores and ceramic-metallic phase interfaces are the centers of material erosion. No clear correlation between the erosion behavior and mechanical properties of coatings was revealed. Contrary to that, sliding wear results were strongly related to the mechanical properties. The WC-Co-Cr and WC-Co samples exhibited higher hardness and higher values of Young’s modulus than the WC-Cr3C2-Ni one. Deposition of the cermet coatings effectively protected the magnesium substrate, which shows low resistance to cavitation erosion and sliding wear when uncoated.

Leszek Łatka is a professor of the Department of Metal Forming, Welding and Metrology in the Faculty of Mechanical Engineering on the Wroclaw University of Science and Technology in Poland. He is associated with the Alma Mater university since 2008. He made his PhD on the area of suspension plasma spraying in 2012. It was a cooperation between University Lille 1 (France) and Wrocław University of Science and Technology. Since 2017 he is a leader of Thermal Spray Team at the native university. In 2020 he defended DSc (habilitation) in the Faculty of Mechanical Engineering. He cooperates with many researches from different countries and institutes (e.g. IPP in Prague, University in Limoges, University West, Fraunhofer IWS Dresden). He published more than 40 papers, mainly according to the thermal spraying, especially SPS and HVOF coatings. He is also a reviewer for many scientific journals, as well as, the invited speaker of many conferences (e.g. RIPT).

Jiří Martan

New Technologies – Research Centre, University of West Bohemia, Pilsen, Czech Republic

With presentation: ADVENTURE project – Advanced coating substrate preparation by shifted and ultrafast laser texturing

Abstract: Thermal spray (TS) coating technology enables creation of functional surfaces with excellent properties for wide range of applications and products. Currently, grit blasting is standard for TS substrate preparation, but it is limited by low reproducibility, residues causing functional failure, substrate materials and production of dust. The ADVENTURE project aims to strengthen the TS technology by introducing laser surface texturing (LST) for substrate preparation as clean, flexible and reproducible method. The goals are up-scaling of LST method, development of innovative coating-substrate interfaces and functional testing in TS. Potential applications of the project results are in high added-value components, i.e., for space, aircraft, medical or power industry. Project´s impact will be high productivity and reliability of LST, improved adhesion, lifetime and reliability of coated parts, new coating possibilities and reduced dust pollution and grit material consumption.

Jiří Martan gained Ph.D. in Physics of plasma and thin films and Laser material interaction at University of West Bohemia (UWB) in Czech Republic and at Ecole Polytechnique of University of Orleans, France (2005). He obtained habilitation to associate professor in the field of Mechanical Engineering (Development of measuring systems) at UWB in 2019. He is head of Laser Micro-processing team at NTC, UWB. He focuses on the development of measurement systems for temperature and optical and thermal properties of materials and laser technology systems, special focus on time resolved IR measurements and laser surface texturing (LST). He has been principal investigator or co-investigator of 4 international and 2 national projects. Since 2017, He is a member of Board of Stakeholders of the Photonics21 European technology platform. He is also member of European Laser Institute (ELI) and European Photonics Industry Consortium (EPIC). He also deals with cooperation with industry by specific contractual research projects (e.g. Honeywell International, Continental Automotive, Preciosa Ornela). H-index: 12, international citations: 369, articles in impacted journals: 32, applied research results: 54.

Udo Loeschner

The University of Applied Sciences Mittweida, Faculty of Industrial Engineering, deputy director of Laserinstitut Hochschule Mittweida, Germany

With presentation: High-rate laser texturing for advanced coating substrate preparation

Abstract: Laser surface texturing has been established as an efficient and appreciated method to control and tailor surface functionalities further providing great potential for innovations in modern surface engineering. This is investigated in the presented study for replacing grit blasting technologies by high-rate laser texturing in coating substrate preparation with goal to enhance adhesion and reliability of coated components as well as reducing dust generation and grit material usage. On metallic and ceramic materials, different surface textures, such as dimples, trenches and pillars, were produced by employing up to 3 kW laser powers delivered by continuous-wave fiber lasers as well as nanosecond and femtosecond lasers in combination with polygon mirror based scanner for high-speed surface processing. The laser beam raster scanning at several hundred meters per second is in particular beneficial to reduce thermal loads and stresses to the substrates at these high laser powers avoiding cracking of substrate and coated layers. This was verified by IR thermal monitoring of heat accumulation during the laser process in nanosecond time resolution. Another benefit is the achievement of unprecedented high processing rates ranging up to 300 cm²/min, verifying laser based surface texturing as competitive method compared to grid blasting in coating substrate preparation.

Udo Loeschner is graduated in Physical Engineering from the University of Applied Sciences Mittweida (Germany) in 1998. Thereafter he has been a R&D engineer at the laser institute of the same university. Since 2006 he joined the Rapid Micro Tooling research group to investigate laser micro processing with short and ultrashort pulse laser technologies. He completed his PhD thesis at the Technische Universitaet Ilmenau in 2007. From 2011 to 2016 he was an endowed professor for “high rate laser processing”. In 2016 he became a full professor in the field of laser production technology which includes high rate laser processing. Latest activities are focused on laser-assisted generation of bionic structures, i.e. to control surface properties regarding wettability, fluidics or cell growth. Prof. Loeschner published more than 100 articles in scientific and technical journals as well as conference proceedings. Since 2022 he has been deputy director of Laserinstitut Hochschule Mittweida.

Radek Mušálek

Department of Materials Engineering, Institute of Plasma Physics of the Czech Academy of Sciences, Prague, Czech Republic

With presentation: Adhesion of thermal spray coatings to the surfaces processed by fast laser texturing

Abstract: Thermal spraying commonly demands roughening of the component surface in order to provide sufficient adhesion of the coating to the substrate. Grit blasting is usually a method of primary choice due to its wide availability, ease of use, and generally good results in many traditional applications. However, some substrate materials are difficult to be roughened by conventional grit blasting, e.g., due to their fragility. Grit blasting may also excessively contaminate the surface by grit blasting medium. Results may be also influenced by gradual decay of grit blasting medium in time. Recent development of high-power lasers enabled efficient and fast laser texturing even for sensitive or hard materials. Another benefit of laser texturing is provision of fairly repetitive patterns on the processed surfaces, which enables to deliberately manipulate the microstructure of the coatings. The study will provide examples of coatings deposited within project ADVENTURE from powders, solutions, and suspensions on various laser-textured surfaces. Potential benefits of laser texturing on the coating adhesion will be discussed.

Radek Mušálek received his PhD in Materials Science at Czech Technical University in Prague. Since 2007, he has been working at the Institute of Plasma Physics of the Czech Academy of Sciences, where he now serves as the head of Dept. of Materials Engineering. He has been principal investigator or co-investigator of 13 research projects and (co-)authored 55 papers in impacted journals (H-index = 17). He enjoys teaching and supervising ingenious students as well as cooperation with industry. His current main research focus is plasma spraying of suspensions, solutions, and hybrid coatings.