Multilayer and high-entropy alloy-based protective coatings for solving the issue of critical raw materials in the aerospace industry

Aerospace is an actively developing industry that continuously requires the implementation of modern technologies. The rapid growth in new vehicle production demands much support. Hence, the problem of resources with complicated supply and distribution is always of current interest. These critical raw materials (CRMs) are involved in almost all areas of aerospace manufacturing and service. An efficient and profitable solution to the problem of critical materials can be found in protective coatings, especially in such advanced concepts as multilayer and high-entropy alloy (HEA)-based coatings. In this paper, we study both ways of manufacturing effective coatings. We have shown that multilayer CrN/MoN coatings with exceptional toughness and hardness could find promising applications in the aerospace industry. The developed strategy for the novel materials screening based on the prediction of their properties has been demonstrated on the example of the refractory HEA-based coatings. A brief state of the art of the EU critical raw materials and their place in the aerospace/defence industry has been given.The study has been partially supported and funded by the Ukrainian state budget via the project “Improved Physical and Mechanical Properties of Multilayer Protective Coatings Based on High Entropy Alloy Nitrides” (project № 0120U100475

Structure and Properties of Nanostructured (Ti-Hf-Zr-V-Nb)N Coatings

Nanostructured coatings of (Ti-Zr-Hf-V-Nb)N were obtained by the Cathodic Arc Vapor Deposition (CAVD) method. To investigate these coatings, a number of complementary methods of elemental and structural analysis were used, namely, slow positron beam (SPB), proton microbeam (μ-PIXE), micro- and nanoelectron beam (EDS and SEM analyses), and X-ray diffraction method (XRD), including method of “α-sin2φ” measurement of a stress-strain state (X-ray strain measurement). Additionally, the texture of coatings before and after annealing up to 873 K (for time of annealing τ=30 min) was also investigated. It was shown that increasing of stress-strain state in the coating during deposition increases the resistance to oxidation at high temperatures of annealing. It was also found that the redistribution of elements and defects, as well as their alignment (segregation), appeared due to thermally stimulated diffusion. It is also connected with the process of spinodal segregation near grain boundaries and interfaces around the grains and subgrains

International Conference on Nanomaterials : Applications and Properties

This book presents the findings of experimental and theoretical (including first-principles molecular dynamics simulation) studies of nanostructured and nanocomposite metal-based materials, and nanoscale multilayer coatings fabricated by physical or chemical vapor deposition, magnetron sputtering, electrospark alloying, ionic layer absorption, contact melting, and high-current electron beam irradiation. It also discusses novel methods of nanocomposite formation, as well as the structure of the deposited films, coatings and other nanoscale materials, their elemental and phase composition, and their physical–mechanical, tribological, magnetic and electrical properties. Lastly, it explores the influence of a various surface modification methods, such as thermal annealing, pulsed laser modification, and thermomechanical and ultrasonic treatment, as well as different properties of nanostructured films

Nanocomposite Multilayer Binary Nitride Coatings Based on Transition and Refractory Metals: Structure and Properties

One area of constant interest in many fields of industry is development of functional multilayer coatings that possess excellent performance characteristics. That is why in our brief review the results of studies of structure and properties of multilayer structures based on binary nitrides of transition or refractory metals obtained by various physical-vapor deposition (PVD) techniques are presented. The influence of substrate temperature, substrate bias voltage, bilayer thickness and interface boundaries on the structure of coatings and their properties, such as hardness, plasticity, wear and corrosion resistance, are discussed in detail. This review may be useful for students and growing community of researchers interested in the synthesis-structure-properties relationship in multilayer coatings based on metal nitrides

Nanomaterials in biomedical application and biosensors (NAP-2019)

This book covers novel and innovative technologies used in development, modeling, chemical/physical investigation and biomedical (in-vitro and in-vivo) trials of nanomaterials and nanocomposites. Novel methods for nanoparticle development and manufacturing are presented, as well as their safety and promising applications. In addition, the book highlights new frontiers in the use of metal / metal oxide nanoparticles, hierarchical nanostructures and organic coatings as sensors for detecting gases, inorganic and organic materials, including biosensors for bacteria and cancers. Organic nanoparticle composites for medical applications (tissue engineering, tissue replacement, regeneration, etc.), including hydroxyapatite NPs, are also covered, together with related in-vitro and preclinical investigations. In closing, the book shares recent findings on orthopedic and dental implant coatings using nanoparticles, their biological efficacy and safety

MXenes—A New Class of Two-Dimensional Materials: Structure, Properties and Potential Applications

A new class of two-dimensional nanomaterials, MXenes, which are carbides/nitrides/carbonitrides of transition and refractory metals, has been critically analyzed. Since the synthesis of the first family member in 2011 by Yury Gogotsi and colleagues, MXenes have quickly become attractive for a variety of research fields due to their exceptional properties. Despite the fact that this new family of 2D materials was discovered only about ten years ago, the number of scientific publications related to MXene almost doubles every year. Thus, in 2021 alone, more than 2000 papers are expected to be published, which indicates the relevance and prospects of MXenes. The current paper critically analyzes the structural features, properties, and methods of synthesis of MXenes based on recent available research data. We demonstrate the recent trends of MXene applications in various fields, such as environmental pollution removal and water desalination, energy storage and harvesting, quantum dots, sensors, electrodes, and optical devices. We focus on the most important medical applications: photo-thermal cancer therapy, diagnostics, and antibacterial treatment. The first results on obtaining and studying the structure of high-entropy MXenes are also presented

Effect of Bilayer Thickness and Bias Potential on the Structure and Properties of (TiZr/Nb)N Multilayer Coatings as a Result of Arc-PVD Deposition

This work is devoted to the study of the formation of nanostructured multilayer coatings (TiZr/Nb)N on the surface of an AISI 321 steel substrate depending on the deposition parameters of the Arc-PVD method. The results of the X-ray diffraction analysis showed the formation of solid solution (TiNb)N and ZrN in the multilayer coatings with an FCC structure, ε-NbN with a hexagonal structure, as well as with a small volume fraction of the ε-Ti2N and β-Nb2N phase. On the basis of phase composition data, it is possible to assume that an increase in the number of bilayers leads to a decrease in the nitrogen concentration in the bilayers and, consequently, to a decrease in the volume fraction of ε-NbN and β-Nb2N nitrides. In all investigated systems obtained at −100 V and −200 V bias potentials, ε-NbN is the main phase. The study of the element distribution over the thickness of the (TiZr/Nb)N coating confirms the results of the X-ray diffraction analysis. The use of the structure model in the form of alternating layers allows for significantly improving the adhesion characteristics of the protective coating, as well as ensuring their high hardness. Based on the experimental results, it is possible to analyze changes in the mechanical and tribological properties of multilayer coatings depending on the number of applied bilayers. The results of the study of the elastic modulus and hardness of multilayer coatings (TiZrNb)N with different numbers of bilayers showed that a large number of bilayers (small thickness of each individual layer) shows the lowest value of hardness. It is assumed that as the bilayer thickness decreases, the coating characteristics are closer to the monolayer alloy than to the multilayer structure