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Stay up to date with the latest developments in the field of electrolytic and high-temperature corrosion and our current research projects.

DECHEMA Corrosion Center @ ACHEMA Pulse 2021

31.05.2021

The DECHEMA Centre for Corrosion and Corrosion Protection (Corrosion Centre) presents its range of services for industrial customers at ACHEMA Pulse, the digital live event for the process industry.

Expand your business network, exchange ideas about innovative solutions and get inspired. ACHEMA Pulse is the interactive digital platform supporting you in being informed, connected and in your business also in these challenging times.

Take the opportunity to find out more about our services in the fields of corrosion testing and individual corrosion protection concepts for industry as part of the exhibition platform from 31 May to 30 June 2021, and to contact the DFI team of experts in person - we look forward to seeing you!

The latest DFI research results will be presented in the live programme on 16 June 2021 on the following topics:

„Degradation of metals by metal dusting: It's relevance to conventional chemical industry and process related to renewable energies“
16.06.2021, 14:20 - 14:40 h, Congress Channel 3

„Tribocorrosion of titanium materials and development of wear resistant coatings“
16.06.2021, 15:50 - 16:10 h, Congress Channel 3

New IGF project investigates influence of grinding parameters on corrosion properties of aluminum components

27.05.2021

In the course of the production of semi-finished aluminum products, grinding processes are used in practice even before surface finishing (pretreatment/coating) for various reasons. This is intended to generate a homogeneous appearance of the component or to compensate for any unevenness created during shaping. However, grinding the sheet metal deforms the surface and makes it more susceptible to corrosion attack.

The micro- or sub-microcrystalline Beilby layer responsible for this provides ideal conditions in particular for the occurrence of so-called filiform corrosion. This is a kind of corrosion creep in a thread-like manner which detaches the coating. Since there is a lack of detailed knowledge about the influence of the grinding parameters, such as grinding time, contact pressure, type and grit size of the abrasive, there are few or no specifications for the grinding of aluminum semifinished products in the various branches of industry. The result is inconsistent surface finishes wherever grinding operations are performed on aluminum semi-finished products.

In order to clarify how the commonly used grinding parameters influence the corrosion properties of coated semi-finished aluminum products, the IGF project 21673 BG with the topic "Influence of grinding parameters on the corrosion properties of coated aluminum materials" was started at the DECHEMA Research Institute (DFI) on 1 April 2021. The project will be executed in cooperation with the Institute for Corrosion Protection Dresden (IKS) and Fraunhofer IKTS Dresden and is scheduled for completion in the fall of 2023.

In addition to heat input during grinding, fundamental investigations on the microstructure of the deformation zone, as well as the surface activity and corrosion behavior of the materials will be carried out. On the basis of the project results, instructions for action in the form of standards or even norms are to be drawn up and made available to SMEs, with cost savings expected through the avoidance of cases of damage and through process optimization. At the same time, the improvement of product quality in the several economic sectors (e.g. automotive industry, facade construction, rail vehicle sector) would strengthen the competitiveness of the SMEs involved.

Start of the new IGF research project “Ultrasound impregnation of aluminum”

21.05.2021

Aluminum alloy based components used in the aerospace or automotive industries are commonly anodized or treated with a chemical conversion before paints and varnishes are applied or they are adhesively joined. This is done in order to improve the adhesion of the paints and bonding agents as well as the corrosion protection. However, some components of these alloys like intermetallic phases containing elements like copper or silicon can lead to undesirable corrosion effects and result in erroneous coatings or later in defects.

These issues are being addressed in the new IGF research project “Ultrasound assisted surface chemical processes for aluminum alloys to improve corrosion protection and adhesion of paints and bonding agents” (IGF no. 21700 N, 01.04.2021 – 30.09.2023). Together with the chair of Technical and Macromolecular Chemistry of Paderborn University existing approaches will be optimized and new processes developed to prevent the detrimental effects of corrosion-active compounds during the anodization and conversion treatments.

The focus is put on the pretreatment steps of the alloys under the application of ultrasound. Next to the chemical treatments ultrasound presents an additional method to modify the surface by mechanical as well as by chemical and thermal means. The aim is to remove, deactivate or mask the corrosion-active components on the surfaces allowing the subsequent processes to produce more homogeneous and defect-free surface layers.

The results of the project being funded via the AiF will be made available to SMEs of the surface treatment sector, thus enabling them to implement these new innovative and resource efficient methods and to produce high quality products with improved corrosion properties.

New IGF project "Antimicrobial peptides for inhibition of biocorrosion"

21.04.2021

Microbially influenced corrosion (MIC) or biocorrosion is a major factor contributing to the economic damage caused by corrosion. MIC occurs as a result of the presence or metabolic activity of microorganisms, primarily bacteria. Currently, to inhibit bacterial colonization of material surfaces, environmentally hazardous biocides targeting the metabolism of bacteria are often used in pipelines or tanks and production facilities. However, the extracellular polymer layer (biofilm) in which the bacteria are embedded has a protective function that can often only be countered by increasing the concentration of the costly and harmful biocides.

Therefore, the development of suitable methods for corrosion protection is of immense importance, both from an economic point of view and for the benefit of human health and the environment.

In order to effectively reduce biocorrosion on ferrous materials, the new IGF research project “Antimicrobial peptides for inhibition of biocorrosion” (IGF 21670 N, 01.04.2021-30.09.2023) at the DECHEMA Research Institute in cooperation with the Technische Hochschule Mittelhessen (THM) aims to develop an environmentally friendly process that inhibits the attachment and biofilm formation of microorganisms relevant to corrosion by means of antimicrobial peptides (AMP). The AMPs, usually <30 amino acids short, often show a very fast and strong inhibitive effect on bacteria. At the same time, there is hardly any formation of resistance to AMPs by the bacteria. Synthesis of the peptides using standard methods allows the production of individually designed peptides that are optimally tailored to the application. Combined with the biodegradability of AMPs, they offer an ecologically and economically attractive alternative to conventional biocides.

On the one hand, the project aims to identify new or optimized AMPs that offer a protection against microbially influenced corrosion. For this purpose, promising molecules will be identified from the wide range of peptides, synthesized and tested for their protective effect on ferrous materials. The efficacy of AMPs will be tested both directly on metal surfaces and in stabilized peptide solutions to suppress biofilm formation in closed water circuits.

In addition to extended material service life, the development of a new corrosion protection method is expected to offer technical and economic benefits, especially for small and medium-sized enterprises in the field of surface and cleaning technology.

DFI at conference “HTCPM – High-Temperature Corrosion and Protection of Materials”

23.03.2021

The DECHEMA Research Institute (DFI) is participating in this year's “HTCPM – High-Temperature Corrosion and Protection of Materials” conference with three scientific contributions. The internationally renowned meeting on high temperature corrosion and protection of materials will take place virtually from 28 March to 2 April 2021 (http://htcpm2020.com/en/).


Monday, 29 March 2021, 13:30 - 14:00 h
“Effect of elevated pressure on the oxidation of cast iron alloy in water vapor”

Mathias Christian Galetz1, Clara Schlereth1, Ceyhun Oskay1, Stefan Wanjura2

1DECHEMA-Forschungsinstitut, Frankfurt am Main, Germany; 2Siemens AG Power and Gas Division

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Wednesday, 31 March 2021, 12:10 - 12:40 h
“High-Temperature Corrosion of Additively Manufactured Cu and NiCu Alloys in Carburizing CH4 and CO-Containing Atmospheres”

Katrin Jahns1,2, Robin Bappert3, Christian Haase3, Anke S. Ulrich4, Clara Schlereth4, Christine Geers5, Peter Böhlke2, Mathias C. Galetz4, Ulrich Krupp3

1Faculty of Engineering and Computer Science, University of Applied Sciences Osnabrück, Osnabrueck, Germany; 2KME Germany GmbH & Co. KG, Osnabrück, Germany; 3Steel Institute IEHK, RWTH Aachen University, Aachen, Germany; 4DECHEMA-Forschungsinstitut, Frankfurt am Main, Germany; 5Energy and Materials, Chalmers University of Technology, Gothenburg, Sweden

More information on the project: Additive Manufacturing of Materials for C-rich High-Temperature Environments which suppress Coking and Metal Dusting by Catalytic Inhibition

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Wednesday, 31.March 2021, 17:00 - 17:30 h
“Cr-rich Cr-Si Alloys for Temperatures Beyond Ni-Bases Superalloys: Improvement by Platinum Alloying”

Anke Silvia Ulrich1, Alexander Knowles3, A. Bhowmik, Christine Geers2, Valentina Cantatore2, Michael Wharmby4, Itai Panas2, Mathias Christian Galetz1

1High Temperature Materials, DECHEMA-Forschungsinstitut, Frankfurt am Main, Germany; 2Sweden Energy and Materials, Chalmers University of Technology, Gothenburg, Sweden; 3University of Birmingham, School of Metallurgy and Materials, Birmingham, UK; 4DESY Photon Science, Hamburg, Germany

More information on the project: Heat-Treatable Cr-Alloys for Ultra-High Temperature Applications

IGF project on development of thermal barrier coatings on titanium materials

16.02.2021

In order to reduce the kerosene consumption of aircrafts and hence CO2 emissions, the thermal efficiency of turbines is increased by increasing their gas inlet temperatures. However, the high temperatures exceed the application range of the metallic materials used, which is why critical components such as the combustion chamber or turbine blades are provided with a porous ceramic zirconium oxide coating for thermal insulation. Such thermal barrier coatings are very complex and cost-intensive using electron beam evaporation or atmospheric plasma spraying.

Aim of the IGF project, which was started on 1 November 2020 at the DECHEMA Research Institute, is the “Development of thermal barrier coatings on titanium and titanium aluminides by plasma-electrolytic oxidation” (more about the project). The versatile properties of the generated PEO coating are intended to save time and costs for the coating of turbine components and open up a new sales market for small and medium-sized companies in the surface technology sector.

This interdisciplinary project is being worked on across working groups at the DECHEMA Research Institute and should be completed by 31 October 2022.

Within the plasma-electrochemical PEO process, a ceramic conversion layer of the metallic substrate is created in aqueous electrolytes by applying a high voltage between a workpiece (anode) and a cathode. The inherent structure of the crystalline and porous PEO ceramic is used to achieve effective thermal insulation with low thermal conductivity values and good adhesion properties. In order to meet the project objectives, suitable ZrO2 containing electrolytes will be developed and an adequate PEO process for low and high frequencies or duty cycles is to be designed.

BMBF NanoMatFutur junior research group of Maren Lepple at DFI granted

12.01.2021

The Federal Ministry of Education and Research (BMBF) granted 1.6 million Euro for the new junior research group of Dr.-Ing Maren Lepple at DECHEMA Research Institute. The project "MEO-TBCs - Multicomponent Equiatomic Oxides as High Performance Materials for Future Thermal Barrier Coatings" was selected for funding as part of the NanoMatFutur competition for junior researchers of the BMBF. Over the next five years, Maren Lepple and her junior research group will work on the development and characterization of new high-entropy oxides for high-temperature applications.

New materials that are stable over long periods of time at high temperatures in aggressive atmospheres are necessary to make combustion processes, such as in aircraft turbines, more efficient by increasing the process temperature. This can significantly reduce the consumption of fossil fuels and exhaust emissions. This is of particular importance in the aviation industry, since on the one hand, transport activities in international air traffic have been continuously increasing since 1990, and on the other hand, no new sustainable propulsion technologies, such as those already used in the automotive sector, have been developed.

Ceramic thermal barrier coatings are used to protect the metallic components in the hottest zones of a gas turbine. However, the materials used so far only have limited temperature resistance above 1200 °C in long-term use. Yet a higher process temperature is required to increase turbine efficiency. "So-called multicomponent equiatomic oxides, or simple high-entropy oxides, are a new promising class of materials for use as thermal barrier coatings at temperatures above 1200 °C", explains Maren Lepple, "which have promising properties such as high-temperature stability, low thermal conductivity and good mechanical properties that are crucial for use as thermal barrier coatings".

High entropy oxides consist of at least four to five different metal ions in approximately the same concentration. They form a single phase and are present in a simple crystal structure. "Due to the many possible compositions, specific properties can be adjusted. Thus, these materials are not only of interest for high-temperature applications, which are the focus of this project, but also as electrode materials in batteries or as catalysts. The interdisciplinary orientation of DFI gives me the opportunity to investigate the potential of high-entropy oxides also with regard to these applications and to collaborate with other research groups, such as technical chemistry or electrochemistry," says the junior research scientist happily.

IGF project on development of corrosion-resistant magnesium materials

20.10.2020

The light metal magnesium gains increasing attention due to its good availability and low density, so it is of interest as construction material for automotive and aviation industries. Disadvantagous are its low corrosion and wear resistance. In order to leverage the industrial use of magnesium materials a targeted development of suitable coatings offering a good corrosion protection is necessary.

Therefore on 1 July 2020 the IGF-project 20627 BG „Optimization of plasma-electrolytic ceramic oxide layers on magnesium alloys through an improved interplay of the current-voltage regime and adapted inhibitors“ has been started at the DECHEMA research institute (DFI). The project will be executed in cooperation with the Fraunhofer IKTS Dresden and will be finished at the end of 2022.

Goal of the project is to create an innovative and economical anodising process with superior corrosion resistance compared to current corrosion protective coatings. “The new process will be characterized e.g. by an improved current-voltage regime allowing to decrease the energy needed to create a ceramic layer with a comparable thickness”, said Robert Sottor, the responsible scientist for the project at the DFI. In addition “smart” nanoparticles or -containers, loaded with inhibitors, will be incorporated into the ceramic layer to gain a significantly higher corrosion protection.

First DFG Research Training Group at DFI: “MatCom – ComMat”

01.10.2020

For the first time, DECHEMA-Forschungsinstitut (DFI) is involved in a Research Training Group (Graduiertenkolleg) of the German Research Foundation (DFG). Under the title “MatCom-ComMat: Materials Compounds from Composite Materials for Applications in Extreme Conditions”, the DFI research group High Temperature Materials is investigating new material systems over an initial funding period of 4.5 years. Project partners are the Karlsruhe Institute of Technology (KIT) and the Technical University of Darmstadt (TUD).

The official starting date of the DFG research training group was 1 April 2020. Due to the Corona pandemic, the kick-off meeting only took place on 14/15 September in Bad Herrenalb. It served for presenting the results collected so far and for co-ordinating further collaborative research.

The goal is to develop novel material systems which allow increasing the operating temperature of combustion engines and processes to over 1300°C. This increase also raises the efficiency of combustion engines, which leads to a significant reduction of fuel consumption and of exhaust emissions.

This development is of outstanding significance particularly in view of the CO2 reduction necessary to fight global climate change. In spite of technological development of renewable energy resources, fossil fuels such as oil and gas will keep playing a key role in global energy supply also in the future. In addition, CO2-neutral synthetic fuels based on hydrocarbons (solar fuels) will become more important in the future.

The materials used for components of combustion engines play a key role in this development. Currently used materials are nickel-based alloys (superalloys) with zirconium oxide-based (YSZ) thermal barrier coatings. Their operating temperatures are limited to 1200°C.

The novel approach of the research training group is the combination of metallic/intermetallic composite materials based on refractory metals as substrate with polymer-derived ceramic nanocomposites as thermal barrier coatings. Only the combination of these two material systems yields their high potential of application. The composite materials made of alloys offer excellent micro-stability and creep resistance at ultrahigh temperatures, whereas the polymer-derived ceramics exhibit outstanding high-temperature stability and low intrinsic heat conductivity.

The research group High Temperature Materials is involved with two sub-projects in the frame of the research training group: In one sub-project the oxidation behaviour of the ceramic coatings is investigated, in the second sub-project the hot corrosion of refractory metals-based substrates is researched. This offers the opportunity for the research group to apply their long-standing expertise in the area of high temperature corrosion under extreme environmental conditions (such as oxidation, erosion, or hot corrosion) which occur in combustion engines. KIT is primarily focused on developing intermetallic substrate materials, while TUD investigates the synthesis of the ceramic coating materials.

Research training groups have the primary purpose of promoting young academics: “We are delighted to be able to make a significant contribution to the science and business location Germany by qualifying PhD students in the frame of this topically focused research programme”, comments Associate Prof. Dr. Mathias Galetz, member of the executive board of DFI and head of the research group High Temperature Materials. “Thus DFI stresses its important role in training young scientists”, Galetz continues. Currently DFI is training over 30 PhD students and post-docs within its ongoing research activities.

Further information can be found on the GRK website

DECHEMA Corrosion Centre at the Virtual EUROCORR 2020

03.09.2020

The DECHEMA Research Institute (DFI) is participating in this year's European Corrosion Congress EUROCORR with six scientific contributions. The annual international meeting on corrosion research will take place virtually for the first time from 7th September to 11th September 2020 (www.eurocorr.org ).

The presentations of the DFI scientists from the working groups "Corrosion" and "High Temperature Materials" range from topics such as the corrosion behaviour of additively manufactured components under metal dusting conditions, to the wear properties of NiAl, titanium and TiAl materials for use in medical technology and aerospace, to the investigation of corrosion phenomena on cathodically protected pipelines. As members of the international scientific committee, two of DFI's working group leaders, Prof. Dr.-Ing. Wolfram Fürbeth and Associate Prof. Dr.-Ing. Mathias Galetz, are in charge of the lecture series on coatings as well as on high-temperature corrosion.

At the virtual exhibition taking place in parallel, the experts of the DECHEMA Corrosion Centre will present their services in the field of electrolytic and high-temperature corrosion. From advice on corrosion-resistant materials to the development of corrosion protection coatings and individual corrosion tests and approaches to problem solving, the DECHEMA Corrosion Centre covers the entire range of material and process issues of industry (www.corrosion-center.com ).

The European Corrosion Congress EUROCORR is the annual meeting of the European Corrosion Federation (EFC), where leading corrosion experts from academia and industry meet and present their latest research in the field of corrosion and material protection.  This year the congress will be held as an online event facing the current pandemic situation. This will provide a platform for the scientific exchange of experts and young scientists who have research priorities in the field of corrosion, even in difficult times.

Far more than “rust”: Corrosion concerns everyone - World Corrosion Awareness Day

22.04.2020

Wherever metal is used, corrosion damage can occur - sometimes with devastating consequences. World Corrosion Awareness Day on 24 April 2020 aims to draw attention to this.

As you read this article, more than 1,000 kilograms of steel are crumbling due to corrosion worldwide. Silently and irreversibly. Corrosion and the damage it causes are usually only noticed when massive material failure has occurred, costing lives in the worst cases. The collapse of the Morandi Bridge in Genoa, Italy, in 2018 may have been one of the saddest events in the recent past caused by corrosion damage, which received a lot of attention in the media and society. What consumers usually know as "rust" is a serious problem: corrosion can occur wherever metallic components are used. The "World Corrosion Awareness Day" on 24 April 2020 draws attention to this frequently occurring, often underestimated damage phenomenon.

High economic damage due to corrosion

The annual losses caused by corrosion in an industrialised country like Germany correspond to approximately 3-4 % of the gross domestic product. This means that in Germany alone, between 110 and 140 billion euros will be lost in 2019 due to corrosion damage. Corrosion destroys valuable resources and is also often associated with high consequential costs for industry. Against this background, good corrosion protection concepts represent an enormous economic factor.

Many years of DECHEMA expertise in the field of corrosion research

The DECHEMA Research Institute in Frankfurt am Main has been conducting corrosion research for more than 50 years, covering a wide range of corrosion phenomena, from aqueous environments to very hot gas atmospheres. The corrosion researchers' first goal is to understand how corrosion occurs. On this basis, they develop corrosion protection concepts and corrosion-resistant materials to prevent future corrosion damage. With this expertise, the DECHEMA Corrosion Centre also helps industrial companies to avoid corrosion problems.

Successful project examples

Two concrete project examples show how close cooperation between the DECHEMA Research Institute and industrial partners has made it possible to better identify, understand and avoid corrosion problems:

In recent years, for example, a phenomenon has been investigated that many users of gas boilers are confronted with - without them knowing that it is corrosion. When natural gas is burned, sulphuric acid can form and deposit on the heat exchanger in the boiler. This sulphuric acid attacks the material; as a result, the fine channels of the heat exchanger become clogged. The boiler breaks down, has to be cleaned or even replaced. Through a better understanding of the corrosion processes that take place, gas boilers can be designed and adjusted in a targeted manner in the future so that corrosion is contained.

Much larger heat exchangers are installed in waste incineration or biomass plants, for example, in order to be able to use the waste heat as steam to generate energy. Depending on the fuels and the mode of operation, the metal pipes in these plants often have a service life of only one to two years and then have to be repaired at great expense. The scientists analysed in different plants which elements and mechanisms contribute particularly to corrosion in each case. On this basis, the service life of the pipes can be significantly extended for specific plants.