DVS_Bericht_393LP

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Properties and Materials – Tribological Coatings Design and Development of Cost-Effective Equipment for Tribological Evaluation of Thermally Sprayed Abradable Coatings .................................................................... 704 K. Bertuol, F. R. E. Rivadeneira, B. C. N. M. Castilho, C. Moreau, P. Stoyanov Thermal Spray and other Processes – Additive Manufacturing Investigation of Mechanical Properties of Cobalt Chromium Additively Manufactured Using Direct Energy Deposition: Experimental Study and Finite Element Analysis .................................................................................................. 712 D. Smith, P. Pickett, T. Grabowski, J. Thorpe, F. Azarmi Thermal Spray and other Processes – Cold Gas Spraying Heat treatment effects on structural and mechanical features of cold sprayed 3D Aluminium part ......................................................................................................... 724 M. Sokore, S. Deng, H. Liao, R. N. Raoelison Cold-Sprayed Aluminum Alloys: Exploring the Differences Between 6061 and 7075 ........................................................................................................................ 732 K. Rafiee, E. Barbosa de Melo, P. Vo, M.H. Martin, S. Yue Thermal Spray and other Processes – Modeling & Simulation Investigation of the pore formation during the cold spray additive manufacturing of a bulk aluminum part .................................................................................................. 743 M. Sokore, S. Deng, H. Liao, R. N. Raoelison Nozzle geometry optimization for cold spray applications by using 3D-CFD calculations ...................................................................................................... 751 J. Gutiérrez de Frutos, A. List, F. Gärtner, T. Klassen Thermal Spray and other Processes – Plasma Spraying Influence of Concentrated Solar Power on Plasma Sprayed Hybrid Thermal Barrier Coatings ............................................................................................................. 759 J. Dudik, I. Hulka, T. Tesar, F. Lukac, R. Musalek Thermal Spray and other Processes – Pre- & Post-Treatment Lightblast ....................................................................................................................... 768 T. Wanski, P. Herwig, J. Hauptmann Authors and Co-Authors ……………………………………………………………….. 773
Development of Dense and Low Oxide Titanium Coatings for PEMWE Application K. Bobzin, H. Heinemann, E. Olesch, K. Radermacher* Surface Engineering Institute (IOT), RWTH Aachen University, Aachen, Germany A key technology to minimise CO2-emissions is the production of hydrogen from water electrolysis. The proton exchange membrane water electrolysis (PEMWE) consists of a stacked system out of bipolar plates (BPP), porous transport layers (PTL) and a membrane electrode assembly (MEA). Research activities are ongoing to minimize material input, reduce costs and increase the performance. For example, the BPP on the anodic side of the stack is currently manufactured of bulk titanium and its substitution by a Ti-coated steel substrate is economically interesting. The main requirements for the BPP-coating are a high coating density, a low electrical resistance and a long lifetime in a harsh electrochemical environment. Coating application on substrates of s ≤ 0.5 mm thickness is conducted with three thermal spraying technologies: Cold Gas Spraying (CGS), High Velocity Air-Fuel (HVAF) spraying and High Velocity Oxy-Fuel (HVOF). Substrate preparation is examined as well. Coating development is conducted with regards to coating thickness, density and oxidation. The examination of coatings includes roughness analysis, structural and chemical analysis. The results allow an evaluation of the suitability of thermally sprayed Ti-coatings by the structural properties for the PEMWE application. Among the three tested processes, CGS is the most suitable for this type of application. The three chosen thermal spraying processes are examined for coating application on metal sheets in context of PEMWE for the first time. 1 Introduction The use of thermally sprayed coatings for water electrolysis to produce hydrogen is known in the context of alkaline water electrolysis (AWE) and solid oxide electrolysis cell (SOEC). The proton exchange membrane water electrolysis (PEMWE) is another electrolysis variant which is characterised by a higher hydrogen production rate under smaller cell dimensions [SGG11]. The PEMWE entails a stacked system out of bipolar plates (BPP), porous transport layers (PTL) and a membrane electrode assembly (MEA). The BPP is a structural cell component responsible for fluid transport, electrical conductivity and mechanical stability of the electrochemical cell. Typically, BPPs are manufactured from commercially pure titanium sheets with a thickness of 0.3 mm ≤ s ≤ 1 mm. In order to facilitate the manufacturing process and to reduce costs, steel-based BPPs are currently investigated. Because of the acidic conditions in the PEMWE cell and the high cell voltage of of U = 2 V, corrosion of the steel-based BPP is to be expected. In order to protect the steel-based BPP from corrosion, a corrosion protection coating with a high coating density as a barrier between steel and electrolyte should be deposited on the steel surface. According to the Pourbaix diagrams [Pou74], titanium, tantalum and niobium are the most suitable materials for this type of protection coating under the PEMWE conditions. The coating development for potential corrosion protection of the BPP is yet at the beginning. Physical vapor deposited (PVD) coatings have been examined for PEMWE application since they have been established in fuel cell (PEMFC) application. In Langemann et al. [LFM+15] PVD-coatings of Au and TiN were examined. Both coatings were infiltrated with the electrolyte because of pin holes in the PVD-coating causing corrosion of the underlying substrate. In Rojas et al. [RSS+21] single and multilayer coating architectures of CrN and TiN in combination with different chemical resistant steels were investigated. Regarding CrN, the protective passivation layer of Cr2O3 was destroyed at electrochemical potentials of E > 1 V vs NHE. For single layer TiN coatings high dissolution rates of iron were measured indicating corrosion of the underlying substrate. In multilayer systems this was not observed which is, according to the authors, contributed to the lower numbers of coating defects in a multilayer system. Based on this literature review, while TiN and CrN are commonly used for coatings in the PEMFC, the PVD coatings have shown a worsened electrochemical behaviour under PEMWE conditions. Coating deposition with thermal spraying for the BPP involves process related challenges. On the one hand, the coating material is limited to commercially pure (CP) titanium with the affinity to oxidise easily during the spraying process. The relevance of the process-related oxidation for the application is explained more in detail in chapter 2.3 Coating Analysis. On the other hand, the BPP substrate should encompass a thickness of just s ≤ 0.5 mm. Evidently, a high coating density is important as well in order to prevent the underlying substrate from corrosion. Thermally sprayed coatings for the PEMWE have been studied firstly by Gago et al. [GAG+14] using vacuum plasma spraying (VPS). By VPS, titanium coatings with an oxygen content of just ω ≤ 1% are possible [LLH+87]. <strong>DVS</strong> 393 1
Page 1 and 2: 2024 PROCEEDINGS ITSC 2024 Internat
Page 5 and 6: ITSC 2024 International Thermal Spr
Page 7 and 8: Preface ITSC 2024: ADVANCING THERMA
Page 11 and 12: Table of contents Preface Time Sche
Page 13 and 14: COAXquattro: A Versatile High-Power
Page 15 and 16: Hot corrosion behaviour of yttria s
Page 17 and 18: Metals Processing Optimization of t
Page 19 and 20: Studies of Particle Deformation and
Page 21: Applications - Automotive Industry
Page 25 and 26: 2.3 Coating Analysis The coated sub
Page 27 and 28: in Figure 5, is comparably low whic
Page 29 and 30: 7 Literature [BHB+23] [GAG+14] [LFM
Page 31 and 32: that using sinter-crushed La0.8Sr0.
Page 33 and 34: (a) (b) Figure 2. Morphologies of (
Page 35 and 36: The XRD patterns of APS-sprayed NZS
Page 37 and 38: 4 Conclusions The NZSP electrolytes
Page 39 and 40: Cold Atmospheric Plasma Metallizati
Page 41 and 42: Figure 2. SEM (a-c) and EDX (d) ana
Page 43 and 44: Figure 5. Setup of Plasma Coating U
Page 45 and 46: Figure 9. Metallographic cross-sect
Page 47 and 48: Figure 12. Metallographic cross-sec
Page 49: Comparative Studies of SUS316L Laye

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