Intermetallic Alloys and Intermetallic Matrix Composite Coatings

A special issue of Coatings (ISSN 2079-6412). This special issue belongs to the section "Ceramic Coatings and Engineering Technology".

Deadline for manuscript submissions: closed (20 February 2024) | Viewed by 5048

Special Issue Editors


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Guest Editor
Departament of Materials and Machinery Technology, University of Warmia and Mazury, Oczapowskiego 11 St., 10-719 Olsztyn, Poland
Interests: intermetallics; microstructure characterization; phase transformation; multiphase nanocomposite intermetallics/ceramics/cermet coatings; multifunctional hybrid coating systems; thermophysical properties; elastic properties characterization up to 1000 °C; thermal stability; residual stresses; adhesive, wear and corrosion properties characterization; D-gun and HVOF ultrasonic metallization spraying; powders metallurgy
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Departament de Ciència i Enginyeria de Materials (CEM), Universitat Politècnica de Catalunya, Barcelona, Spain;
Hyperion Materials & Technologies, P.I.Roca, Carrer de la Verneda, 12, 24, 08107 Martorelles, Spain
Interests: intermetallics; cemented carbides; powder metallurgy; pressing and sintering; thermal spray coatings (CGS, HVOF, APS); optical, scanning and transmission electron microscopy; phase transformation; characterization techniques; high temperature wear; sliding wear; abrasive wear; fatigue wear; frettig wear; cavitation and erosion wear; electrochemical corrosion; hot corrosion, oxidation; residual stresses
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Unlike conventional metal alloys, which could be described as a base material to which certain percentages of other elements have been added, intermetallic compounds have a particular chemical formula with a fixed or narrow range of chemical composition. In addition, instead of their atoms being linked with relatively weak metallic bonds, the bonding may be partly ionic or covalent, which gives them an ordered crystal lattice. Some intermetallics can maintain this order until their melting point, which is the main reason why they possess a strong stability at high temperatures.

Extensive research has been dedicated to aluminides, especially as bond coats in Thermal Barrier Coatings (TBCs) to overcome the fundamental barriers to higher temperature operations with the requisite durability in future gas turbines. Commonly used types of bond coats are M–Cr–Al–Y (where M is Ni or Co) or Pt-modified aluminide coatings.

Transition metal aluminides based on Ti, Fe, Ni, Co, and Nb are seen as promising due to their potential use as coatings in aggressive environments. They possess sufficiently high concentrations of aluminum to form a continuous, fully adherent alumina layer on the surface when exposed to corrosive, oxidizing, carburizing, and sulfidizing conditions.

Other intermetallics, such as MoSi2, also exhibit an outstanding high-temperature resistance of above 1000ºC. Some of these intermetallics can be reinforced to improve their performances. Examples of this can be found in the case of ZrB2-MoSi2 ultra-high-temperature Ceramic Matrix Composites, or even aluminides alloyed with ceramic phases.

Potential scientific research within the last two decades has focused on the use of thermal spray technologies and laser cladding to produce coatings and optimize their microstructures in order to improve their adhesive and cohesive strength, mechanical, corrosion, oxidation, and wear properties. Such coating technologies may imply some oxidation of the raw material during the deposition process, which actually introduce reinforcement phases that can contribute to changes in the thermophysical properties or increase hardness and wear resistance, but that are detrimental to oxidation and corrosion, since they leave aluminum-depleted areas. To improve the wear performance, ceramic hard phases can also be introduced as a feedstock.

As such, the production of different intermetallic, cermet, and ceramic protective coatings can be simple, beneficial, and highly predictable by various conventional synthesis methods with GMA and GTA processes, thermal (D-gun, HVOF, Arc and plasma) spraying, cold spraying, PVD, CVD, ion implantation, and additive manufacturing processes (SLM, DMLS, LENS, among others).

Therefore, the scope of this Special Issue is dedicated to:

  • Coatings produced by different processes, including but not limited to thermal spray, laser and plasma processing, PVD, CVD, ion implantation, and additive manufacturing processes (SLM, DMLS, LENS, among others), as well as GMA and GTA welding processes that include different intermetallic, cermet, and transition metal aluminides with hard ceramic-reinforcing phases such as carbide, boride, and oxide particulates.
  • Theoretical and experimental research on the deposition mechanisms.
  • Understanding metal–ceramic bonding interfaces and dissolution according to temperature-dependent processing. The micro-joint formation that takes place when the surface particles with non-equilibrium solidification are melting leads to eutectic inclusions, even during amorphous phase formation under the extremely harsh formation conditions of the multilayered structure of the protective coatings.
  • Raw material powder manufacture for protecting intermetallic-matrix composite (IMC) coatings.
  • Mechanical properties and residual stresses of intermetallic and IMC coatings.
  • Understanding the degradation mechanisms of coatings through friction, wear, or other dynamic loading conditions.
  • Understanding aqueous corrosion, hot corrosion in molten salts, and the high-temperature oxidation mechanisms of coatings.
  • Analysis of gas detonation phenomenon, thermodynamic studies, and the numerical modeling of processes in supersonic metallization jet flow.

Prof. Dr. Cezary Senderowski
Dr. Núria Cinca
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

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Published Papers (2 papers)

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Research

12 pages, 4432 KiB  
Article
Design of Metamaterial-Inspired High-Temperature Microwave Sensor on Alumina Ceramics
by Bo Wang, Bei Han, Youwei Li, Fei Gao, Chaohui Chen, Junqiang He and Ke Wang
Coatings 2023, 13(7), 1213; https://doi.org/10.3390/coatings13071213 - 06 Jul 2023
Viewed by 782
Abstract
The issues of high costs and sophisticated circuit structures limit applicability of traditional chipped sensors. This paper innovatively designs a chipless sensor based on the split-ring resonator combined with temperature-sensitive material as the substrate. The alumina ceramics are used as the sensitive material [...] Read more.
The issues of high costs and sophisticated circuit structures limit applicability of traditional chipped sensors. This paper innovatively designs a chipless sensor based on the split-ring resonator combined with temperature-sensitive material as the substrate. The alumina ceramics are used as the sensitive material for reflecting the environment temperature in accordance with its characteristic that its dielectric constant increases monotonically with rising temperature. The simulation demonstrates that the resonant frequency of the sensor monotonically decreases from 8.58 GHz to 8.22 GHz with an offset of 0.36 GHz and a sensitivity of 0.9 MHz/°C for a variation from 500 °C and 900 °C. The sensor designed in this paper has good resonance characteristics, is wireless, passive, and low cost, has a planar structure, and is suitable for various harsh environments. Full article
(This article belongs to the Special Issue Intermetallic Alloys and Intermetallic Matrix Composite Coatings)
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19 pages, 2820 KiB  
Communication
Health and Durability of Protective and Thermal Barrier Coatings Monitored in Service by Visual Inspection
by Andrzej Szczepankowski, Radoslaw Przysowa, Jerzy Perczyński and Artur Kułaszka
Coatings 2022, 12(5), 624; https://doi.org/10.3390/coatings12050624 - 03 May 2022
Cited by 9 | Viewed by 2242
Abstract
Protective and Thermal Barrier Coatings (TBC) applied on gas-turbine blades gradually degrade due to oxidation, aluminum depletion and impacts of environmental particles. Among various non-destructive coating testing methods (NDT), visual inspection can be undertaken regularly in service, but it provides little quantitative information, [...] Read more.
Protective and Thermal Barrier Coatings (TBC) applied on gas-turbine blades gradually degrade due to oxidation, aluminum depletion and impacts of environmental particles. Among various non-destructive coating testing methods (NDT), visual inspection can be undertaken regularly in service, but it provides little quantitative information, and only surface defects can be detected. This work aims at in-service monitoring of turbine blades with multilayer coatings applied by atmospheric plasma spraying (APS) in a few variants. They were validated during a series of accelerated mission tests of a retired military turbofan engine in a test cell together with five other technologies. The fifty-hour rainbow test focused on assessing coating durability. Between engine runs, 12 borescope inspections were conducted to monitor the health of the blades. Finally, the blades were disassembled and examined using computed tomography (CT) and metallographic methods. Throughout the testing, 31 newly-coated blades (66%) withstood the tests, producing results comparable to the reference blades. However, 16 blades suffered intolerable failures observed as increased roughness, gradual loss of the topcoat, spallation and minor foreign object damage. Visual inspection results were generally in agreement with subsequent laboratory tests. Full article
(This article belongs to the Special Issue Intermetallic Alloys and Intermetallic Matrix Composite Coatings)
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