Protective and Functional Coatings for Metallic and Ceramic Substrates

This selection of ten papers, published in 2019 by researchers and institutions based in various countries around the world, allows an appreciation of the variety and significance of ongoing research in the wide field of protective and functional coatings. The most noteworthy investigations conducted in the area of surface protection are currently proceeding at a similar rapid pace in a twofold direction toward deeper and increasingly reliable knowledge of degradation and protection mechanisms as well as technological optimization of the selection and design of new materials, coating deposition processes, and characterization methods. This summarized collection serves as a representative essay of the collective worldwide efforts toward the development of more durable surfaces. Both organic and inorganic coatings are included among the protection strategies from a large variety of deposition processes, with interesting examples of organic–inorganic composites being proposed. Major attention is devoted to protection from both electrochemical and chemical corrosion of different metallic alloys and to advanced SiC-SiC composites exposed to the aggressive environments of gas turbines. Examples of modelling of wear corrosion examples are also reported. A dedicated space was intentionally devoted to the selection of papers detailing examples of the applicability of advanced characterization techniques. As an example of the wide field of research on innovative functional coatings, one study presents Mo alloys as an electrocatalytic material for the hydrogen evolution reaction. A comprehensive review of directed energy deposition additive manufacturing of metallic components completes this collection

Book of Abstracts of 11th Iberian Conference on Tribology

info:eu-repo/semantics/publishedVersio

Additively Manufactured Coatings

Functional coatings are cost-effective means to protect substrates from wear, corrosion, erosion, tribocorrosion, high temperature and high pressure in extreme environmental conditions. These are primarily manufactured through metal/ceramic powder deposition in a subsequent layer by layer fashion on the substrate materials. In all cases, the functional coatings need to be reliable for the intended application. The emerging techniques in 3D printing/additive manufacturing can be utilized to develop high-performance functional coatings. These methods provide geometrical precision, flexibility in geometrical complexity, customization of the coating layers, and reduce the raw materials waste, keeping the manufacturing cost low while addressing many of the technical barriers of conventional coating methods. With the rapid development of cutting-edge value-added technologies in aerospace, nuclear, military, space, and energy industry, 3D printing/additive manufacturing techniques will be major advantages. Novel functional coatings and 3D printing/additive manufacturing techniques will be critical to value-added components in the future development of technologies. The book provide an overview of the recent development in coating manufacturing techniques and potential to use in high-end engineering applications

Corrosion and Degradation of Materials

Studies on the corrosion and degradation of materials play a decisive role in the novel design and development of corrosion-resistant materials, the selection of materials used in harsh environments in designed lifespans, the invention of corrosion control methods and procedures (e.g., coatings, inhibitors), and the safety assessment and prediction of materials (i.e., modelling). These studies cover a wide range of research fields, including the calculation of thermodynamics, the characterization of microstructures, the investigation of mechanical and corrosion properties, the creation of corrosion coatings or inhibitors, and the establishment of corrosion modelling. This Special Issue is devoted to these types of studies, which facilitate the understanding of the corrosion fundamentals of materials in service, the development of corrosion coatings or methods, improving their durability, and eventually decreasing corrosion loss

Effect of Composition and Build Direction on Additively Manufactured Hastelloy X Alloys

Microcracking has caused premature failure and reduction in properties in additively manufactured (AM) Hastelloy X. The purpose of this research is to meet or exceed the mechanical properties of wrought Hastelloy X by modifying the composition and build direction of Hastelloy X manufactured using Direct Metal Deposition (DMD). Tensile testing, scanning electron microscopy (SEM), and metallography were performed on the samples. ANOVA was used to analyze the dependence that the properties had on build direction and composition. The nominal composition wrought samples had a yield strength of 310.1 MPa and a 60.79% Elongation. Alloy P60-X18 in a horizontal build had the highest yield strength of 363.67 MPa because it is the most solid solution strengthened alloy. Vertically-built P60-X18 had the highest ductility of 78.62%. Altering the composition had a greater effect on yield strength than changing the build direction. Overall, changing composition resulted in a higher yield strength while maintaining high ductility; therefore, the additively manufactured parts would be suitable for use in an application. Further modification of the solid solution strengthening elements could be performed to precisely match or exceed the wrought Hastelloy X properties. Additionally, corrosion, high-temperature, and application-specific properties should be verified in the new alloys

Technology of Welding and Joining

In this book, you will find information on new materials and new welding technologies. Problems related to the welding of difficult-to-weld materials are considered and solved. The latest welding technologies and processes are presented. This book provides an opportunity to learn about the latest trends and developments in the welding industry. Enjoy reading

Corrosive wear of multi-layer Fe-based coatings laser cladded from amorphous powders

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Since amorphous alloys exhibit good wear and corrosion resistance, they are supposed to be applied as a candidate implant material. In this work, using laser cladding, Multi-layer Fe-based alloy coatings were fabricated from amorphous powders on 316L stainless steel (SS) substrate. When the number of cladding layers increases, the microstructure of the coating was mainly composed of γ-Fe firstly, then evolved to γ-Fe and α-Fe solid solutions, and then to a composite of amorphous and crystalline phases. The surface hardness of the coating was also enhanced consequently to over 1200 HV. During reciprocate sliding against an Alumina ball in a simulated body fluid (Ringer’s solution), the volume loss and the coefficient of friction (COF) of the coatings generally decreased firstly and then increased with the number of cladding layers. During sliding at open circuit, the drop in open circuit potential (OCP) of all the Fe-based coatings, except for the 1-layer one, was not as significant as that of the 316 SS substrate. Moreover, when applying a cathodic potential during sliding, no obvious protective effect was obtained for the coatings, which indicates that the multi-layer Fe-based coatings possess a good corrosion-induced wear resistance in comparison to 316L SS. Because of the formation of an electric double layer, the fixed potential of 100 mVSCE or -600 mVSCE was beneficial to reduce the COF, especially for 316L SS. The tribocorrosion at OCP showed that the 2-layer coating possessed the best corrosive wear resistance, and its COF and volume loss were about 3 and 5.6 times lower than those of the substrate. The material loss in Ringer’s solution at OCP is mainly controlled by the mechanical wear for the coatings and the synergism between corrosion and wear for the substrate. Furthermore, this work provides a way to optimize the tribology system by adjusting the number of cladding layers to reduce COF and wear in a simulated body fluid

Environmental and Industrial Corrosion

Nowadays, it is generally accepted that in the natural and industrial environments, corrosion and pollution are interrelated harmful processes since many water, air and soil pollutants accelerate corrosion, and corrosion products such as rust, oxides and salts, also pollute water bodies at ports, rivers, dams, canals and shipyards. Both are pernicious processes that impair the durability of the infrastructure assets, the industry efficiency and profitability and the quality of the environment. Therefore, it is essential to develop and to apply corrosion engineering control methods and techniques, in particular those being environment-friendly. In this crucial time of worldwide energy crisis and economic turmoil, cost effective corrosion control will extend the life of the infrastructure saving large expenses in materials, equipment and structures. This book will contribute to achieve this important mission

Corrosion Performance of Additively Manufactured Alloys and Hot Corrosion

Additive manufacturing (AM) has gained attention in recent years due to its unique properties in the fabrication of complex parts. Same as any other new topics, in some areas, there is still a lack of enough knowledge and there is the need for further investigations to enable the applications of AM parts widely in industries. ‎Chapter 2, and ‎Chapter 5 to ‎Chapter 8 of this report are focused on the corrosion properties of the parts and coatings fabricated using the laser powder bed fusion based AM method or laser surface processing method, including a comprehensive review. Laser powder bed fusion based AM was used to prepare copper alloy, titanium alloy, and stainless steel AM parts, and laser surface modification was performed on Fe-14Cr alloy. The application of nickel superalloys is well known in various industries. ‎Chapter 3, ‎Chapter 9, ‎Chapter 10 are a part of a DOE-funded project which has the final goal of producing Inconel 939 based superalloy parts with additive manufacturing method. The first step was to modify its composition to reach a better fatigue behavior (‎Chapter 9) with the help of phase composition and antiphase boundary energy associated with each phase. Since the lack of information about the hot corrosion properties of the newly designed alloys, the last chapter has been dedicated to evaluating Inconel 939 corrosion performance at elevated temperatures

Fabrication, characterization of high-entropy alloys and deep learning-based inspection in metal additive manufacturing

Alloying has been used to confer desirable properties to materials. It typically involves the addition of small amounts of secondary elements to a primary element. In the past decade, however, a new alloying strategy that involves the combination of multiple principal elements in high concentrations to create new materials called high- entropy alloys (HEAs) has been in vogue. In the first part, the investigation focused on the fabrication process and property assessment of the additive manufactured HEA to broaden its engineering applications. Additive manufacturing (AM) is based on manufacturing philosophy through the layer-by-layer method and accomplish the near net-shaped components fabrication. Attempt was made to coat AlCoCrFeNi HEA on an AISI 304 stainless steel substrate to integrate their properties, however, it failed due to the cracks at the interface. The implementation of an intermediate layer improved the bond and eliminated the cracks. Next, an AlCoCrFeNiTi0.5 HEA coating was fabricated on the Ti6Al4V substrate, and its isothermal oxidation behavior was studied. The HEA coating effectively improved the Ti6Al4V substrate\u27s oxidation resistance due to the formation of continuous protective oxides. In the second part, research efforts were made on the deep learning-based quality inspection of additive manufactured products. The traditional inspection process has relied on manual recognition, which could suffer from low efficiency and potential bias. A neural-network approach was developed toward robust real-world AM anomaly detection. The results indicate the promising application of the neural network in the AM industry --Abstract, page iv