Article
Materials Science, Ceramics
Antonio Mulone, Satyapal Mahade, Stefan Bjorklund, Dennis Lundstrom, Bjorn Kjellman, Shrikant Joshi, Uta Klement
Summary: This study investigated the feasibility of depositing graphene nanoplatelet-reinforced yttria-stabilized zirconia composite coatings using suspension plasma spraying. The presence of graphene nanoplatelets in the composite coatings was confirmed by Raman spectroscopy and the desired microstructure was observed through scanning electron microscopy analysis. The thermal stability of the graphene nanoplatelets in the coatings was studied by subjecting them to different isothermal treatments, and it was found that the graphene nanoplatelets were retained up to a temperature of 500 degrees C with an increase in defect concentration.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Batuhan Bal, Aligul Buyukaksoy
Summary: The study focuses on using yttria doped bismuth oxide ceramics as electrolyte supports and applying zirconia coatings to prevent reduction upon contact with hydrogen. However, the reaction between Zr source and YDB substrate as well as the choice of polymerization extent play crucial roles in crack formation and film conductivity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Ceramics
Shen J. Dillon, Yu-Feng Shen, Gregory S. Rohrer
Summary: By investigating the variation of grain boundary energy, the characteristics of grain boundaries in 8% yttria-stabilized zirconia were identified, with a focus on the impact of [100] orientation and [100] twist boundaries. The study results indicate that by manipulating the microstructure to increase the relative areas of [100] twist boundaries, the oxygen ion conductivity of the material can be enhanced.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Guanyu Song, Jesse Adamczyk, Yensil Park, Eric S. Toberer, Christopher J. Hogan
Summary: Aerosol deposition (AD) is a coating technique where particles are impacted onto a substrate at reduced pressures, leading to consolidation. By synthesizing particles in the gas phase, size-controlled ceramic particles can be injected into AD systems, eliminating the need for aerosolization. The combined use of ultrasonic spray pyrolysis (USP) and AD results in thick yttria-stabilized zirconia (YSZ) coatings with high thermal conductivities.
ADVANCED ENGINEERING MATERIALS
(2021)
Article
Materials Science, Ceramics
Lukas Theis, Frank Kern
Summary: Partially stabilized zirconia ceramics with different gadolinia content were prepared by co-milling, spray granulation, axial pressing, and pressureless sintering. The redistribution of stabilizers at high sintering temperatures was observed by XRD. Substituting gadolinia for yttria reduced the stabilizer content in the tetragonal phase and increased the tetragonality, transformability, and toughness of the materials, while decreasing the hardness. The cubic content increased with increasing gadolinia content, as predicted by thermodynamic considerations.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
M. Mohammadi, G. Becker, S. Diener, J. -M. Tulliani, N. Katsikis, P. Palmero
Summary: This study demonstrated the feasibility of using commercial yttrium oxide partially stabilized zirconia spray-dried granules instead of submicron particles for robocasting of ceramic parts, achieving high-density monolithic dense parts. By optimizing the formulation and drying conditions, the material exhibited ultra-fine and highly sintered microstructures with fewer and smaller defects.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
M. Faryna, K. Glowinski
Summary: This study computed the probability distributions of grain boundaries based on their macroscopic boundary parameters for yttria-stabilized zirconia samples with different grain sizes. The datasets collected using 3D EBSD technique provided both grain misorientation and boundary plane parameters. The distributions of the five parameters were computed using kernel density estimation and showed several prominent peaks that exceeded the level of random distribution. The collected dataset, containing 64,506 distinct grain boundaries, is the largest of its kind for zirconia and allowed for the investigation of rare boundaries.
Article
Materials Science, Ceramics
Marziyeh Danesh, Damien Mauran, Richard Berry, Marek Pawlik, Savvas G. Hatzikiriakos
Summary: In this study, cellulose nano crystals (CNC) were used as a dispersant in water-based suspensions of zirconia to investigate their stabilization in ceramic processing. The optimal pH value and minimum CNC concentration for producing stable highly concentrated suspensions were determined. The adsorption of CNC nanofibers around the zirconia particles was observed by scanning electron microscopy (SEM), which contributed to the achieved stability. The suspensions with the lowest viscosity and highest stability were obtained with 30 wt% zirconia particles at pH 4 and 1 wt% CNC.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Vikram Hastak, Edward Jonas Gildersleeve, Srikanth Batna, Ashutosh Suresh Gandhi, Sanjay Sampath
Summary: Yttria-stabilized zirconia thermal barrier coatings were deposited by air plasma spraying using different purity feedstock powders and subjected to short-term low-temperature annealing. Significant structural changes and changes in thermal conductivity and elastic modulus were observed, with high-purity coatings showing larger changes compared to commercial purity coatings.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Sung Il Park, Byung Chan Yang, Jihyun Kim, Jaeyoon Ko, Gyung-Min Choi, Jihwan An, Jungwan Cho
Summary: Yttria-stabilized zirconia (YSZ) doped with yttrium has been widely used in electronic and energy devices. In this study, we report the thermal conductivity of YSZ thin films with varying Y2O3 content deposited by plasma-enhanced atomic layer deposition (PEALD). The results show that the thermal conductivity decreases with increasing Y2O3 doping concentration, mainly due to increased phonon scattering by oxygen vacancies. Our PEALD YSZ films have higher thermal conductivities compared to previously reported films, possibly due to their relatively larger grain sizes.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Qaisar Khushi Muhammad, Michael Scherer, Alexander Karl Opitz, Stefanie Taibl, Christin Boehme, Marcus Rohnke, Juergen Janek, Shuang Gao, Juergen Fleig, Till Froemling
Summary: This study investigates the influence of mechanically induced dislocations on the electrical conductivity and oxygen transport in YSZ. Distinctly aligned regions with abundant and deficient dislocations are generated using advanced mechanical deformation methods. Electrical characterization reveals highly conducting effects of dislocation-induced strain within the material. Targeted oxygen tracer diffusion experiments confirm the enrichment of oxygen incorporation within the dislocation bundles. Therefore, mechanically induced dislocations have the potential to serve as a design element for tuning bulk ionic transport in YSZ.
Article
Materials Science, Coatings & Films
Yujun Zhang, Gaoqi Wang, Tingting Kong, Shuo Yao, Junling Wu
Summary: This study aimed to improve the bonding strength between zirconia dentures and natural teeth by infiltrating synthesized fluorapatite glass-ceramics on the unsintered zirconia surface. Comprehensive evaluations of microstructure, phase characterization, surface morphology, mechanical properties, and bonding strength were conducted. The results showed that the infiltrated zirconia with fluorapatite glass-ceramics exhibited enhanced bonding strength and durability.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Materials Science, Ceramics
Hiroaki Nakade, Eita Tochigi, Bin Feng, Yukio Nezu, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara
Summary: Tetragonal yttria-stabilized zirconia thin film was successfully fabricated using a pulsed laser deposition method, with a single crystalline structure and homogeneous distribution of Y3+ ions, but containing small-angle tilt grain boundaries.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Aulia Sukma Hutama, Lala Adetia Marlina, Chien-Pin Chou, Stephan Irle, Thomas S. Hofer
Summary: A set of density-functional tight-binding (DFTB) parameters were developed for simulations of ZrO2, Y2O3, and YSZ materials, laying the ground work for realistic simulations in fuel cells and catalysts. Validation of the parameterization showed good agreement with experimental data and density functional theory calculations, with accurate predictions of structural and vibrational properties. The developed DFTB parameters demonstrated advantages in computational resources for simulating complex models of YSZ-containing systems.
Article
Materials Science, Ceramics
Benjamin Kowalski, Jamesa Stokes, Patrick. E. E. Albert, Pete. E. E. Lauer, Douglas. E. E. Wolfe
Summary: This study investigates the effect of grain size, areal density, and aspect ratio on the infiltration of CMAS into yttria stabilized zirconia. The infiltration depths ranged from 6 up to 85 μm depending on the test conditions.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Coatings & Films
Georg Mauer, Christian Moreau
Summary: This perspective paper summarizes the authors' view on the role of process diagnostics and control in thermal spray processes, and describes the current situation in terms of control strategies and sensors. The authors believe that through the use of models, sensors, and machine learning tools, it will be possible to develop coatings with specific target characteristics with fewer experiments, and implement an efficient control strategy for high reproducibility and reliability. The identification of existing knowledge gaps helps to guide future research needs.
JOURNAL OF THERMAL SPRAY TECHNOLOGY
(2022)
Article
Materials Science, Coatings & Films
P. Khamsepour, C. Moreau, A. Dolatabadi
Summary: Cold spray is promising in the aerospace industry for repairing damaged metallic components, but its drawback is the high porosity of sprayed samples. Utilizing high-velocity air fuel (HVAF) technology can increase sample density and particle bonding, but a proper finite-element simulation is needed to understand the effect of particle deformation.
JOURNAL OF THERMAL SPRAY TECHNOLOGY
(2022)
Article
Thermodynamics
Mohammad Mahdi Nasiri, Ali Dolatabadi, Christian Moreau
Summary: The flattening process of a droplet impacting a solid surface is crucial in various industrial applications. In this study, a numerical model is developed to investigate the formation of fragmented splats during droplet flattening and solidification in plasma spraying conditions. The numerical results show that gas desorption from the surface produces a barrier layer, affecting the heat transfer and spreading of the droplet.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Materials Science, Ceramics
Hediyeh Khatibnezhad, Fabian Ambriz-Vargas, Fadhel Ben Ettouil, Christian Moreau
Summary: In this study, TiO2 coatings with different phase contents, oxygen contents, and roughnesses were produced using suspension plasma spraying (SPS) with varying hydrogen flow rates. The presence of anatase phase was found to enhance the photocatalytic activity of the coatings.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Engineering, Chemical
Bruno C. N. M. de Castilho, Venkata Naga Vamsi Munagala, Sima A. Alidokht, Navid Sharifi, Stephanie Bessette, Mary E. Makowiec, Raynald Gauvin, Pantcho Stoyanov, Christian Moreau, Richard R. Chromik
Summary: Coatings containing silver as a solid lubricant can reduce friction. The mechanisms of silver migration in thermally sprayed coatings are not fully understood. This study observed diffusion and higher concentration of silver at wear tracks, but no silver layer on the surface. Instead, a multilayered structure was observed on PS304 while a smooth tribolayer was observed on PS400.
Article
Materials Science, Coatings & Films
Vahid Jalilvand, Saeed Mohammadkhani, Fadhel Ben Ettouil, Lionel Roue, Daniel Guay, Ali Dolatabadi, Christian Moreau
Summary: SPS-sprayed (Co,Ni)O coating was investigated as a potential material for inert anode applications in Al production. In-flight particles and splats formed on heated metal substrates were studied to understand the melting and mixing of NiO and CoO powders during spraying. SEM, EDS, and x-ray diffraction analyses helped clarify the formation of different crystalline phases in the coatings. The intermixing of NiO and CoO primarily occurred on the substrate surface, while the metallic nickel phase could also form in the coatings.
JOURNAL OF THERMAL SPRAY TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
P. Khamsepour, C. Moreau, A. Dolatabadi
Summary: In solid-state deposition techniques, the initial conditions of particles and substrates are crucial for particle deformation and adhesion strength to the substrate. The presence of an oxide layer increases the required critical velocity for particle adhesion, while particle temperature has no significant effect on adhesion between the particle and substrate.
JOURNAL OF THERMAL SPRAY TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
Farzam Arhami, Fadhel Ben Ettouil, Christian Moreau
Summary: This research addresses the challenges of spraying Yb2Si2O7 environmental barrier coatings, including high amorphous phase formation tendency, desirable microstructure and phase composition, and silicon evaporation. By depositing high crystalline Yb2Si2O7 using atmospheric plasma spray without auxiliary heat-treating, vacuum chamber, or subsequent furnace heat treatment, cost, time, and energy savings are achieved. The spraying process with controlled silicon evaporation and an optimum fraction of the Yb2SiO5 secondary phase leads to exceptional crystallinity levels and a desirable microstructure. Decreasing the plasma power from 90 to 53 kW reduces silicon mass loss but increases porosity fraction.
JOURNAL OF THERMAL SPRAY TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
J. Oberste-Berghaus, M. Aghasibeig, A. Burgess, P. Khamsepour, C. Moreau, A. Dolatabadi
Summary: Ti-6Al-4V is a widely used alloy in the aerospace industry due to its exceptional properties. Efforts are being made to develop additive manufacturing technologies for this alloy. Thermal and cold spray methods are also being explored to create near-net-shaped parts. By lowering the flame temperature and using miniaturized HVOF systems, it is possible to improve the deposition quality and spatial resolution of the buildup.
JOURNAL OF THERMAL SPRAY TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
P. Khamsepour, J. Oberste-Berghaus, M. Aghasibeig, F. Ben Ettouil, A. Dolatabadi, C. Moreau
Summary: High-velocity air-fuel combustion process can deposit metallic particles with minimum oxidation and decomposition. The study focused on using an inner-diameter HVAF gun to produce dense Ti-6Al-4V coatings. Increasing air and fuel pressure and nozzle length improved particle velocity and resulted in improved density and hardness of the coatings, while increasing spraying distance had a negative effect.
JOURNAL OF THERMAL SPRAY TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
G. Y. Koga, A. R. C. Nascimento, F. B. Ettouil, L. C. M. Rodrigues, G. Zepon, C. Bolfarini, C. S. Kiminami, W. J. Botta, R. Schulz, A. Costa e Silva, C. Moreau, F. G. Coury
Summary: Thermally sprayed Cr40Co40Ni20 coatings were produced by HVOF and HVAF, forming chromia and spinel compounds upon oxidation at high temperatures. Chromia formed at the inner layer and spinel at the outer layer. HVAF coatings showed less oxidation compared to HVOF coatings. However, the formation of spinel and oxide in the coatings led to regions susceptible to corrosion in chloride-rich electrolyte.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
Sina Mirzai Tavana, Mehdi Hojjati, Andre C. Liberati, Christian Moreau
Summary: This paper investigates the fabrication and performance evaluation of a solid particle erosion resistant layer on polymer-based composites. Coating materials including tungsten carbide-cobalt, martensitic chromium stainless steel, and alumina-titania were deposited using air plasma spray (APS) to enhance erosion resistance. A stainless steel mesh was incorporated during composite fabrication to protect the composite fibers during grit blasting and thermal spraying, improving the adhesion between coatings and substrate. Tests were conducted to assess mechanical and tribological properties. Results showed that coating bonding strength significantly improved with identified processing parameters. Coating materials with brittle behavior exhibited higher erosion resistance on stiff substrates, while ductile coatings were more suitable for less stiff substrates like carbon fiber reinforced composites.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
Amit Roy, Venkata Naga Vamsi Munagala, Payank Patel, Navid Sharifi, Sima A. Alidokht, Mary Makowiec, Richard R. Chromik, Christian Moreau, Pantcho Stoyanov
Summary: Tantalum oxide-based coatings have been developed by suspension plasma spraying and their tribological behavior at high temperatures has been evaluated. The coatings exhibit uniform and dense nanostructure with no phase transformation. The friction coefficient of the coatings decreases slightly from 0.9 at 25 degrees C to 0.8 at 300 degrees C, while the wear rate decreases by more than 50%. The decrease in friction and wear at elevated temperatures is attributed to the formation of a smooth continuous layer and a stable transfer film.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Venkata Naga Vamsi Munagala, Sima A. Alidokht, Navid Sharifi, Mary E. Makowiec, Pantcho Stoyanov, Christian Moreau, Richard R. Chromik
Summary: CoMoCrSi alloys with intermetallic Laves phases exhibit high hardness and excellent wear resistance. Diamalloy3001 coatings deposited using HVOF spraying process showed low wear rates at room temperature due to the formation of tribolayers composed of Co, Cr, and Mo oxides. However, at elevated temperatures, detachment of tribolayers and formation of cavities increased the wear rates.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Metallurgy & Metallurgical Engineering
Eslam M. Fayed, Vladimir Brailovski, Mohammad Jahazi, Mamoun Medraj
Summary: This study investigates the potential of microwave hybrid heating (MHH) technique as an efficient post-heat treatment route for Inconel 718 (IN718) superalloy processed by laser powder bed fusion (LPBF). The LPBF-IN718 alloy is post-heat-treated using an industrial microwave (MW) oven and a conventional heat treatment. The MW treatment decreases the fraction of intergranular delta-phase and leads to more precipitation of MC-type carbides in the matrix compared to the conventional treatment.
CANADIAN METALLURGICAL QUARTERLY
(2023)