In this study, an aqueous suspension containing fine aluminum oxide and coarser titanium nitride (TiN) powders was prepared and processed using high-velocity suspension flame spraying (HVSFS) to produce thick TiN/ Al2O3 composite coatings (>50 µm). The influence of spraying parameters, such as total gas flow and flame stoichiometry, on the microstructure, phase composition, mechanical, and tribological properties was investigated. The results demonstrate that TiN can be successfully deposited under atmospheric conditions using the HVSFS process, achieving a homogeneous distribution of TiN particles within the alumina matrix. This composite structure led to a significant increase in microhardness. Furthermore, the TiN/ Al2O3 coatings produced with λ = 0.8 exhibited improved wear resistance and a reduced coefficient of friction compared to pure Al2O3 coatings.

The present study investigates the effect of thin porous ceramic coatings on implant stability, focusing on two materials: a calcium alkali orthophosphate (GB14, Ca2KNa(PO4)2) and β-tricalcium phosphate (β-TCP), with and without copper (Cu) incorporation. The coatings were applied to titanium implant surfaces (CP Ti, grade 2) and characterized for porosity and microstructure. The in vivo performance of the material is assessed in a New Zealand White rabbit model. Following defined healing periods, biomechanical push-out testing were performed. The results of β-TCP/Cu for cancellous bone show that Cu-doped coatings exhibit significantly improved bone integration compared to their Cu-free counterparts. The enhanced fixation is attributed to the bioactive and potential antibacterial properties of copper, which may stimulate osteogenesis and the presence of supraparticles in the Cu samples. Furthermore, the incorporation of β -TCP supraparticles into the ceramic matrix increases overall coating porosity, facilitating deeper bone ingrowth and improved mechanical interlocking. This structural change results in improved osseointegration compared to less porous coatings. This structural change results in improved osseointegration compared to less porous coatings. The results of this study demonstrate that combining copper incorporation with enhanced porosity through supraparticles can improve implant stability by shortening the time required for the transition from primary to secondary stability. This approach offers a promising strategy for optimizing surface design in orthopedic and dental implants.

Decarbonizing aviation aims to reduce greenhouse gas emissions from aircraft operations, paving the way for sustainable air travel. This endeavor requires adopting advanced technologies, alternative fuels, high-performance coatings and efficient engineering solutions that minimize environmental impact while maintaining performance and safety standards. Two of the most prevalent and cost-effective methods for applying protective and functional coatings to aerospace components are thermal spray and physical vapor deposition. These techniques enhance the durability and efficiency of several components, resulting in fuel savings and an extended service life across the aviation industry. This supports the broader aim of transitioning the aviation industry to net-zero emissions and sustainable growth. This roadmap explores how these two coating techniques can promote sustainable aviation and identifies the challenges and opportunities in the aerospace sector for researchers and manufacturers of thermal spray and physical vapor deposition (PVD) coatings. It also proposes research directions to address these challenges and discusses the role of AI, which is crucial for breakthrough technologies in process optimization and integration, new coating development and coating design optimization. The roadmap is organized into 20 concise subsections, each focusing on a specific topic. Renowned specialists in each area were invited to summarize the current status of their field, discuss the challenges it faces, and offer recommendations for necessary research and development to overcome these issues. Together, these contributions vividly highlight the essential elements of the field and the challenges that lie ahead. The innovative ideas and concepts outlined in the roadmap reveal that the future path is both expansive and far-reaching. A decade after the JTST released its roadmap on thermal spray, which emphasized the processes, coatings, and applications of thermal spray, the current roadmap shifts its focus to spray processes and vapor deposition methods aimed at decarbonizing aviation. Academic and industry experts are collaborating to share insights on how thermal spray and vapor deposition techniques and coatings can advance sustainable aviation and the necessary research to overcome associated challenges. This roadmap can serve as a valuable reference point for researchers aiming to understand the field’s trajectory and identify critical gaps to address.

Sliding bearings in pumps operating under corrosive and insufficiently lubricated conditions are subjected to high levels of wear and degradation, frequently resulting in accelerated component failure. These bearings typically utilize tungsten carbide with a cobalt binder (WC-Co) due to its superior resistance to wear and corrosion. However, growing concerns regarding the sustainability and limited availability of tungsten and cobalt have intensified the efforts to develop alternative, resource-efficient solutions. To address this challenge, a novel ceramic coating composed of chromium carbide-chromium oxide (Cr3C2/Cr2O3), deposited using high-velocity suspension flame spraying (HVSFS), was evaluated as an environmentally sustainable replacement for WC-Co coatings in sliding bearing applications. Shaft sleeves were coated and subsequently cylindrical grinding was applied to achieve tight dimensional tolerances and optimal surface finish. Ultrashort-pulsed laser surface texturing was then employed to create engineered dimples designed to improve friction behavior under challenging lubrication conditions. A fine cylindrical grinding was subsequently applied to remove residual pile-up and flatten inter-dimple areas. Grinding performance evaluation demonstrated 20% reduction in tangential grinding force and 37% improvement in surface roughness (Rz) compared to WC-Co, confirming the coating's suitability for precision finishing. Tribological tests under water-lubricated sliding conditions revealed that laser-textured Cr3C2/Cr2O3 coatings exhibited up to 50% lower wear mass than non-textured coatings and achieved friction coefficients between 0.02 and 0.04, matching WC-Co performance while showing greater stability and lower variability. In speed-ramped Stribeck testing, laser-textured surfaces maintained reduced friction variability and closely followed the frictional trend of WC-Co, particularly in the boundary-to-mixed lubrication regime. These findings highlight the combined advantages of the proposed coating system in terms of machinability, wear resistance, friction control, and operational consistency, offering a viable and sustainable alternative for high-performance sliding bearing applications in water-lubricated environments.

Spinel-type high-entropy oxides (SHEO) have a greater potential for application as OER electrodes. Currently, the conventional preparation route of SHEO electrodes suffers from long-time duration, multi-steps and extra usage of binder. In order to obtain the binder-free SHEO electrodes by a rapid route, the SHEO coatings (Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)3O4 were first-time deposited by solution precursor plasma spraying (SPPS) technique. The phase compositions of the SHEO coatings were characterized by XRD and Raman spectrum. Besides, the oxygen vacancies from the as-sprayed SHEO coatings were confirmed by the XPS spectrum and the Raman spectrum. In addition, under both the three-electrode and overall water-splitting testing conditions, the SHEO-35 sample with nanoflakes exhibited lower overpotential than the SHEO-41 sample with conventional cauliflower-like morphology. The lowest Tafel was obtained by the SHEO-35 sample as well, followed by IrO2 and conventional SHEO-41 sample. Moreover, the nanoflakes-like SHEO-35 sample possessed the highest stability up to 91.65% over 20 h under 100 mA cm-2. In conclusion, this study provides a new technique to facilely elaborate SHEO coatings with controllable surface morphologies, exhibiting high-interest as anode electrodes in water splitting field.

The aim of this work is to propose a novel low-cost non-contact infrared pyrometric technique for in-situ temperature measurement at different depths of the substrate without interfering with the coating process from the backside of the substate. This procedure allows not only to obtain the temperature variation in the region close to the substrate surface, reducing the external interferences associated with the thermal spraying process, but also to observe with high accuracy the temperature variation in the substrate thickness over time, which can be used for the subsequent experimental validation of numerical simulation models of the coating process.

Implant failure after arthroplasty, primarily due to aseptic loosening or periprosthetic joint infection, remains a significant clinical problem. Bioactive ceramic coatings, such as β-tricalcium phosphate (β-TCP), enhance osseointegration and may reduce the risk of aseptic loosening. At the same time, localized antibiotic release from the implant surface represents a promising strategy to prevent early bacterial colonization. The aim of this study was to evaluate the feasibility of incorporating the heat-sensitive antibiotic vancomycin (VAN) into β-TCP coatings using high-velocity suspension flame spraying (HVSFS). We successfully embedded VAN into β-TCP coatings by preparing suspensions containing VAN-loaded supraparticles as feedstock for the HVSFS process. High-performance liquid chromatography analysis confirmed that VAN maintained its chemical integrity during spraying, with spectra comparable to untreated controls, indicating no thermal degradation. The resulting multifunctional coatings therefore combined the osteoconductive potential of β-TCP with the antibacterial activity of VAN. These findings demonstrate that HVSFS is a viable technique for producing bioactive coatings that simultaneously promote bone integration and enable local antibiotic delivery, offering a potential strategy to mitigate both aseptic loosening and infection risks in arthroplasty.

This work highlights the potential of porous, bioactive coatings to advance implant technology and address critical clinical challenges. A key issue in implant coatings is to achieve the balance between infection prevention and successful osseointegration. Although titanium implants are widely used due to their mechanical strength and biocompatibility, their bioinert nature limits integration with bone tissue. To address these issues, porous calcium phosphate (CaP) coatings have been developed to enhance cell attachment and bone growth. However, CaP, especially in the widely used form of hydroxyapatite (HAp), has a low resorption rate, which often leads to prolonged coating stability and impairs natural bone remodeling. To overcome this limitation, magnesium phosphate (MgP), an underexplored but promising biomaterial with high biocompatibility and osteogenic potential, can be introduced. Another innovative strategy is the doping of biomaterials with antibacterial ions, among which copper (Cu) has attracted particular attention. The incorporation of Cu into the coating matrix can significantly reduce the risk of post-operative infection while promoting angiogenesis, a key factor for rapid and stable implant integration. This study presents bone implant coatings composed of tricalcium phosphate (TCP) and Cu-doped MgP clustered nanoparticles (supraparticles) fabricated via high-velocity suspension flame spraying (HVSFS). This particle system addresses current challenges in bone tissue regeneration by synergistically combining the high biodegradability of MgP, the bone-mimicking properties of CaP, and the antibacterial capabilities of Cu. In addition, the HVSFS process enables the creation of thin layers with porous microstructures. Biocompatibility of the prepared coatings was assessed using MG63 osteosarcoma cells, while the antibacterial efficacy was tested against Staphylococcus aureus and Escherichia coli. The incorporation of Cu-doped MgP supraparticles (MgPCu and MgPCu HT) into TCP coatings resulted in high Cu release and pronounced antibacterial efficacy compared to the TCP reference, while the addition of Cu-doped FT supraparticles (FTCu) led to high cell proliferation.

This study investigates the combustion dynamics and decomposition of filled thermoplastic filaments in filament high-velocity oxy-fuel spraying to improve deposition efficiency and coating quality. A quasi-steady-state combustion mechanism is proposed. Filament tip melting, fragmentation, and in-flight decomposition transform the monomodal primary powder with a mean size of 1.8 µm into a trimodal particle size distribution. Peaks occur near 500 nm, 5 µm, and 150-400 µm, with the first two likely from clean melting and decomposition, and the third from material buildup on cooled nozzle walls. Process optimizations varied the stoichiometric ratio ( λ ), feed gas flow rate, and filament diameter, and a copper insert was added to enhance filament decomposition. Coatings were prepared using PBAT filaments containing 70-80 wt.% alumina. Sub-stoichiometric flame conditions, particularly λ ≈ 0.8, gave the highest deposition efficiencies by maximizing flame temperature and promoting polymer decomposition. Reducing the feed gas flow to 5 slpm further improved efficiency, while gas composition had little effect under low flow. Filament diameter influenced efficiency by controlling feed velocity, which in turn affected the filament tip position within the nozzle. The adapted setup and optimized spraying parameters achieved a deposition efficiency of 76%, hardness of 1149 HV0.1, low porosity of 3.0%, and surface roughness values of Ra = 6.9 µm and Rz = 44.8 µm at a feed rate of 4 g/min.

This study investigates the performance of Nichrome coatings, a nickel-chromium alloy containing 20 wt.-% chromium, applied using three thermal spray techniques: powder plasma spray, suspension HVOF, and filament HVOF. Thin, homogeneous coatings approximately 35 mu m thick were deposited onto steel substrates pre-coated with an insulating Al2O3 layer. The oxide content in the coatings varied based on the spraying technique and parameters, ranging from 57 to 64 vol.-% for plasma spraying, 42 to 54 vol.-% for filament HVOF, and 9 to 43 vol.-% for suspension HVOF. The coating's heating performance was evaluated over a temperature range of room temperature (RT) to 700 degrees C. Analytical techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) were employed to investigate the mechanisms affecting temperature-dependent resistivity in relation to the coating microstructure. The results indicate that increased oxidation leads to a decrease in specific resistivity at RT (rho 0). In example, plasma sprayed coatings exhibited lower specific resistivity rho 0 of 0.80 Omega mm2/m. In contrast, suspension HVOF reaches values up to 2.75 Omega mm2/m. At the same time coatings with higher oxidation levels demonstrate an elevated dependence of resistivity as compared to less oxidized coatings. Both can be attributed to changes in the phase composition of the conductive phase as the dominating factor, primarily driven by the preferential oxidation of chromium during the spraying process. Notably, the results provide valuable information for adjusting the coating properties to suit specific needs, such as self-regulating or high-temperature heating applications.

This work presents an exhaustive parametric study of the multi-scale residual stress analysis on arbitrary substrate geometry based on a one-way-coupled thermo-mechanical model in an Atmospheric Plasma Spray process. It was carried out by modifying key process parameters, such as substrate surface geometry, substrate pre-heating temperature, and coating thickness, in an Al2O3 coating process on an aluminium substrate. The relationship of these parameters to the generation of quenching stress, thermal stress and residual stress was analysed at three different sub-modelling scales, from the macroscopic dimension of the substrate to the microscopic dimension of the splats. The thermo-mechanical phenomena occurring during the deposition process at the microscopic level were discussed in the proposed cases. Understanding these phenomena helps to optimise the parameters of the coating process by identifying the underlying mechanisms responsible for the generation of residual stresses. The simulated residual stresses of the 200 μm Al2O3 outer coated aluminium cylinder were experimental validated using the incremental high-speed micro-hole drilling and milling method.

Aseptic loosening and infection are still the main reasons for revision surgery. The contact of the implant is made through the surface, which is coated with calcium phosphate ceramics for better integration into the bone. The aim of the present work is to optimize these coatings by making them thinner (20 μm) and doping them with copper to add antimicrobial functionality. Four different coating materials were used: hydroxyapatite, Bioglass, GB14, and beta tricalcium phosphate. The coatings were applied by high velocity suspension flame spraying. The titanium rods with the coatings were then implanted bilaterally into the femoral condyles in 144 New Zealand White rabbits, and ingrowth was evaluated after 2, 4, 6, 12, and 24 weeks. Biomechanical (previously published), histological, and histomorphometric analyses were conducted. Histologically, Cu-doped HA, GB14, and β-TCP showed normal ingrowth behavior, with the coating not completely degraded after 24 weeks and remaining in contact with the bone. Bioglass showed rapid degradation and calcium loss from the bone. However, no negative effect of Cu doping on bone cells (osteoblasts, osteocytes and connective tissue cells) was observed. Via histomorphometry, Bioglass showed low bone mineralization, while TCP, HA and GB14 revealed an increase in mineralization over time to values between 70%-95%. Comparable results were obtained with the undoped coatings. The bone-coating contact was in a similar range to the mineralization because of the coating's incomplete degradation after 24 weeks. The thinner coating could also be applied to titanium rods of the same quality (as the titanium plates in Burtscher et al.) using HVFSF. In animal experiments, all rods, regardless of the coating, could be well inserted-there was no delamination. Histology and histomorphometry showed that BG was not suitable for long-term coating as it had already degraded after 4 weeks and also caused calcium loss in the bone. The other coatings were clearly more suitable. However, we also found that still far too much coating remained after 24 weeks because it was too dense.

Prosthesis loosening due to lack of osteointegration between an implant and surrounding bone tissue is one of the most common causes of implant failure. Further, bacterial contamination and biofilm formation onto implants represent a serious complication after surgery. The enhancement of osteointegration can be achieved by using bioconductive materials that promote biological responses in the body, stimulating bone growth and thus bonding to tissue. Through the incorporation of antibacterial substances in bioconductive, biodegradable calcium phosphate (CaP) coatings, faster osteointegration and bactericidal properties can be achieved. In this study, Cu-doped CaP supraparticles are spray-dried and suspension-sprayed CaP ceramic coatings with antibacterial properties are prepared using high-velocity suspension flame spraying (HVSFS). The objective was to increase the coatings’ porosity and investigate which Cu-doped supraparticles have the strongest antibacterial properties when introduced into the coating layers. Biocompatibility was tested on human Osteosarcoma cells MG63. A porosity of at least 13% was achieved and the supraparticles could be implemented, enhancing it up to 16%. The results showed that the addition of Cu-doped supraparticles did not significantly reduce the number of viable cells compared to the Cu-free sample, demonstrating good biocompatibility. The antimicrobial activity was assessed against the bacterial strains Escherichia coli and Staphylococcus aureus, with Safe Airborne Antibacterial testing showing a significant reduction in both Gram-positive and Gram-negative strains on the Cu-doped coatings.

AbstractHydroxyapatite (HAp)-coated bone implants are frequently used for orthopaedic or dental implants since they offer high biocompatibility and osteoconductivity. Yet, problems such as infections, e.g. periprosthetic joint infections, occur when implanting foreign material into the body. In this study, HAp coatings were produced via high-velocity suspension flame spraying (HVSFS). This method allows for the production of thin coatings. We investigated the effects of different gas parameters on the coating properties and on the biocompatibility, which was tested on the human osteosarcoma cell line MG63. Furthermore, Copper (Cu) was added to achieve antibacterial properties which were evaluated against standard microorganisms using the airborne assay. Three gas parameter groups (low, medium, and high) with different Cu additions (0 wt.%, 1 wt.% and 1.5 wt.%) were evaluated. Our findings show that porosity as well as hardness can be controlled through gas parameters. Furthermore, we showed that it is possible to add Cu through external injection. The Cu content in the coating as well as the release varies with different gas parameters. Both antibacterial efficacy as well as biocompatibility are affected by the Cu content. We could significantly reduce the amount of colony-forming units (CFU) in all coatings for E. coli, CFU for S. aureus was reduced by adding 1.5 wt.% of Cu to the coating. The biocompatibility testing showed a cytotoxicity threshold at a Cu-release of 14.3 mg/L in 120 hours. Based on our findings, we suggest medium gas parameters for HVSFS and the addition of 1 wt.% Cu to the coating. With these parameters, a reasonable antibacterial effect can be achieved while maintaining sufficient biocompatibility. Graphical Abstract

Recent advancements in ceramic matrix composites (CMCs), including SiC/SiC, C/SiC, C/C, Al2O3 reinforced Al2O3, face various challenges at high temperature applications, including grain growth, sintering, and creep deformation which are leading to strength loss. The new generation of Environmental Barrier Coatings (EBCs) must allow the protection of these CMCs when operating under harsh conditions, which can reach up to 1100 degrees C in some applications, such as gas turbines and certain reforming processes. In this work, 8 wt% yttria stabilized zirconia (8YSZ) applied by Atmospheric Plasma Spraying (APS) on top of a porous alumina oxide matrix with reinforced alumina fibers Al2O3/Al2O3-CMC (OCMC), considering different interfaces, has been studied. Surface morphology and pre-treatment of CMCs is the most challenging part for thermal spray applications. Hence, two different surface structure were used in this work. The results show that the roughness of OCMC can be reduced from Rz = 41.8+6.8 mu m to 20.3+1.1 mu m with the new porous bond coat and plasma sprayed coating, resulting in a homogeneous surface morphology.. In terms of thermal stability, a numerical model that combines Object Oriented FEM (OOF) and Cohesive Zone Model CZM tools, has been developed to evaluate the effect of the porosity of the real microstructure and the characteristics of the interfacial roughness profile, respectively, in CMC/EBC structures. In addition, other materials, such as La2Zr2O7 and Y2O3, have been numerically studied in order to evaluate their suitability as EBC.

This work presents a multi-scale one-way-coupled thermo-mechanical method to determine the residual stress in an Atmospheric Plasma Spray (APS) process. The model uses three submodelling scale levels that range from the entire component (macroscopic) to a splat coating layer (microscopic) dimension. The three-level scale temperature and stress evolutions of an Al2O3 coating material on a flat aluminium substrate were analysed. The quenching stress for different substrate preheating temperatures up to 600 K at the end of the APS coating process was discussed and validated through an experimental in situ curvature method and Stoney’s quenching stress equation.

This work presents a characterisation model for the temperature distribution at different substrate depths during the atmospheric plasma spray (APS) coating process. The torch heat flow in this model is simulated as forced convection defined by a surface, a temperature profile, and a convection coefficient. The simulation model considers three plasma temperature profiles of the Al2O3 coating on a 5 mm thickness flat aluminium substrate. The simple and low-cost experimental procedure, based on a thermocouple, measures the plasma plume temperature distribution of the APS coating system, and their results are used to obtain the parameter values of each of the three proposed plasma temperature profiles. The experimental method for in situ non-contact temperature measurements inside the substrate is based on an infrared pyrometry technique and validates the simulation results. The Gaussian temperature profile shows excellent accuracy with the measured temperatures. The Gaussian approach could be a powerful tool for predicting residual stress through a coupled one-way thermal-mechanical analysis of the APS process.

Carbon fiber-reinforced plastics (CFRPs) have broad applications as lightweight structural materials due to their remarkable strength-to-weight ratio. Aluminum is often used as a bond coating to ensure adhesion between CFRPs and further coatings with a higher melting temperature. However, challenges persist in optimizing their surface properties and adhesion attributes for diverse applications. This investigation explores the impact of sandblasting and plasma pretreatment on CFRP surfaces and their influence on plasma-sprayed aluminum coatings. Two distinct CFRP substrates, distinguished by their cyanate ester and epoxy resin matrices, and two different aluminum powder feedstocks were employed. Plasma pretreatment induced micro-surface roughening in the range of 0.5 µm and significantly reduced the contact angles on polished specimens. Notably, on sandblasted specimens, plasma-activated surfaces displayed improved wetting behavior, which is attributed to the removal of polymeric fragments and augmented fiber exposure. Aluminum splats show a better interaction with carbon fibers compared to a polymeric matrix material. The impact of plasma activation on the coating adhesion proved relatively limited. All samples with plasma activation had deposition efficiencies that increased by 12.5% to 34.4%. These findings were supported by SEM single-splat analysis and contribute to a deeper comprehension of surface modification strategies tailored to CFRPs.

Enhancing osseointegration, the process by which medical implants securely bond to bone, is crucial for improving patient outcomes in orthopedics and dental surgery. Calcium alkali orthophosphates, with their superior bioactivity, resorbability, and chemical resemblance to bone minerals, have emerged as promising candidates for implant coatings. These materials offer improved solubility and lower melting points due to the substitution of calcium with potassium and sodium, along with the addition of magnesium oxide. This study investigates GB14 calcium alkali orthophosphate coatings applied via High Velocity Suspension Flame Spraying (HVSFS), a technique that enables precise control over coating properties. A porosity target of >10% was set to promote bone growth, and we achieved porosities up to 13%, ensuring better cell penetration and stability at the implant-bone interface. Coatings were produced using different gas parameters and distances, with their microstructure and phase composition analyzed using scanning electron microscope (SEM), Vickers hardness testing and X-ray diffraction (XRD). Additionally, roughness and porosity were also assessed. Different coating’s microstructures were achieved by varying stand-off distance and gas parameters. Increasing stand-off distance while reducing gas stoichiometry enabled the production of calcium alkali orthophosphate coatings with fewer cracks, higher porosity and a hardness level comparable to that of state-of-the-art tricalcium phosphate (TCP) coatings. The sample with optimized properties in terms of achieved microstructure and topography was selected for in vitro testing using MG63 osteosarcoma cells to evaluate cell proliferation and adhesion. WST (I) assay, LDH assay, and live/dead staining confirmed the biocompatibility of the coatings, highlighting the potential of HVSFS to enhance osseointegration and outperform conventional methods in implantology. No relevant cytotoxicity could be shown and cells show a good proliferation over time. These results highlight thus the potential of HVSFS to produce thin, bioactive and resorbable coatings to enhance osseointegration.

Recent advancements in ceramic matrix composites (CMCs), including SiC/SiC, C/SiC, C/C, Al2O3 reinforced Al2O3, face various challenges at high temperature applications, including grain growth, sintering, and creep deformation which are leading to strength loss. The new generation of Environmental Barrier Coatings (EBCs) must allow the protection of these CMCs when operating under harsh conditions, which can reach up to 1100 ºC in some applications, such as gas turbines and certain reforming processes. In this work, 8 wt.% yttria stabilized zirconia (8YSZ) applied by Air Plasma Spraying (APS) on top of a porous alumina oxide matrix with reinforced alumina fibers Al2O3/Al2O3-CMC (OCMC), considering different interfaces, has been studied in terms of thermal stability. For this purpose, a numerical model that combines Object Oriented FEM (OOF) and Cohesive Zone Model CZM tools, has been developed to evaluate the effect of the porosity of the real microstructure and the characteristics of the interfacial roughness profile, respectively, in CMC/EBC structures. In addition, other materials, such as La2Zr2O7 and Y2O3, have been numerically studied in order to evaluate their suitability as EBC.