Microbial and viral pathogen contamination of touch surfaces contributes to the rapid transmission of diseases. It has been known for decades that microbes and viruses are rapidly inactivated when exposed to copper and its alloys. Consequently, the use of thermal spray technologies to coat surfaces in healthcare and public settings has been receiving a considerable amount of interest during recent

In plasma spraying, instabilities and fluctuations of the plasma jet have a significant influence on the particle in-flight temperatures and velocities, thus affecting the coating properties. This work introduces a new method to analyze the stability of plasma jets using high-speed videography. An approach is presented, which digitally examines the images to determine the size of the plasma jet core

In this study, the effects of time and temperature of heat treatment on Ni-20 wt.% Al flame spraying coatings were studied. The objectives are to find the optimal sample in terms of microstructure and compare its oxidation resistance with the as-sprayed coating. The coatings were deposited by flame spraying on low carbon (St 37) steel substrate. The specimens were heat-treated in vacuum at 850 °C and

There are many sets of information in the literature (e.g., papers, books and websites) about the great achievements that are expected for aerospace gas turbine engines by the employment of ceramic matrix composites (CMCs) and thermally sprayed environmental barrier coatings (EBCs) in their hot zones (e.g., combustion chambers, vanes, shrouds, blades and afterburners). Among these achievements, it

Loss of mechanical integrity due to thermal aging and subsequent spallation of the ceramic top layer is one of the dominant failure mechanisms in thermal barrier coating systems. In order to predict and avoid such mechanical failure, a strain-based lifetime assessment model is presented for a novel double-layer thermal barrier system. The investigated ceramic system consists of a gadolinium zirconate

Besides conventional industrial demands, thermally sprayed coatings are increasingly used for innovative products. Such an application is the additive manufacturing of electrical components in automotive engineering. In particular, heating units are currently manufactured by a combination of various spray technologies. At present, simpler spraying processes like flame spraying are investigated with

This study deals with Al2O3-13wt.%TiO2-reinforced CoCrFeMnNi high-entropy alloy (HEA) composite coatings prepared by plasma spraying. The effect of the Al2O3-TiO2 ceramic phase on the microstructure, mechanical properties and high-temperature tribological performance of the as-sprayed composite coatings was investigated. The results showed that the composite coatings consisted of a HEA phase with a

Up to now, the role of particle sizes on the impact behavior of ceramic particles in aerosol deposition not yet fully understood. Hence, with the aim to supply a more general understanding, modeling series of low strain rate compression and high-speed impact were performed by molecular dynamics on single-crystalline particles in sizes of 10-300 nm that are tuned to match mechanical properties of TiO2-anatase

Aerosol deposition (AD) is a thick-film deposition process that can produce films tens to hundreds of micrometers thick with densities greater than 95% of the bulk at room temperature. However, the precise mechanisms of bonding and densification are still under debate. To better understand and predict deposition, a self-consistent approach is employed that combines computational fluid dynamics (CFD)

Thermally sprayed coatings improve component lifespan and protect the underlying substrate in high temperature and corrosive environments. The coating adhesion is one of the most important properties with respect to coating performance. Before coating, surfaces are typically cleaned and roughened via manual grit blasting to promote mechanical interlocking of the coating with substrate. With recent

HVOF coatings generally have a high bonding strength and good compactness, which improve the wear, corrosion, high-temperature oxidation, and fatigue properties of the substrate. They are widely used in automobile, home appliance, petrochemical, aerospace, and other fields. The flame flow characteristics and particle in-flight behaviors during the spray process have an essential influence on the coating

Thermoplastics combine high freedom of design with economical mass production. Metallic coatings on thermoplastics enable power and signal transmission, shield sensitive parts inside of housings and can reduce the temperature in critical areas by functioning as a heat sink. The most used technical thermoplastics are polyamides (PA), while the described use cases are often realized using Cu. Consequently

Suspension stability is a key parameter that should be considered in any coating process utilizing a suspension as the main feedstock. Application of water as the liquid phase for suspension preparation is promising due to its availability, low cost and no toxicity. In the present study, the effects of three surfactants, polyethyleneimine (PEI), 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) and

Rare earth element-doped bismuth oxides with the fluorite structure (δ-Bi2O3) exhibit high oxygen ion conductivity at low temperature, which is promising electrolyte materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). However, traditional co-sintering process is not applicable to the manufacturing of IT-SOFCs using low melting point Bi2O3-based electrolyte, while further high-temperature

In aeroengines, thermal barrier coatings (TBCs) are usually utilized to protect the hot components from hot gases. The ability to predict the TBC failure is crucial to avoid economic losses. In this study, plasma-sprayed 8 wt.% yttria-stabilized zirconia (YSZ) coatings were subjected to corrosion by calcium–magnesium–aluminosilicate (CMAS, 33CaO–9MgO–13Al2O3–45SiO2) glass at 1250 °C. After the test

Nano-titania (TiO2) has drawn considerable attention for decades for its excellent photocatalytic activity. The use of photocatalyst TiO2 in the form of surface coating is usually desired for long-term recyclable photocatalytic performances. Yet deposition of the coatings with appropriate nanostructures persists challenging. Thermal spray processing usually triggered loss of photocatalytic anatase

It was known for long that Ni-Al composite powders can be used to deposit self-bonding coating as a bond coat for common ceramic coatings due to the exothermic reaction between Ni and Al. However, it was found that with commercial Ni-Al composite powders with a large particle size, it is difficult to ignite the self-propagating reaction between Ni and Al to form Ni-Al intermetallics by plasma spraying

The hydraulic runners and many other components are exposed to cavitation phenomena and the erosion occurs, and normally are repaired by arc welding processes. However, the heat input from the welding causes microstructural changes in the components materials. Considering the martensitic stainless steel CA6NM, the welding thermal cycle reduces its fracture toughness and consequently the structural

In this study, the function of rare earth (RE) oxides added in boronizing agents was studied by analyzing not only the boronized titanium (Ti6Al4V) but also the agent materials at 900–1050 °C. XRD results showed that low-melting-point RE borates were formed in the boronizing processes. The existence of the RE borates probably provided a partially liquid boronizing environment for the titanium alloys

A novel coating system of Nb-Ni-Si intermetallic compound was designed for components serving in the aggressive environment containing molten glass. Cold spray process was employed to deposit Nb-Ni-Si coating on the nickel-based superalloy substrate (IN 718), and post-spray heat treatment was adopted to promote the formation of intermetallic compounds in the as-deposited coating. The microstructure

Thermally sprayed cermet coatings are adequate solutions to improve cavitation and wear resistance of hydraulic turbines made of stainless steel (SS), especially in rivers with a high sediment load, such as the Madeira River in Brazil. However, some cermets are easily dissolved in river water, leading to premature failure of the coating and costly maintenance. Moreover, galvanic corrosion induced by

In this study, Cr3C2-25NiCr cermet coatings were fabricated by atmospheric plasma spraying on 304 stainless steel substrate. Then, the coatings were sealed with a Polytetrafluoroethylene (PTFE) emulsion by using two methods: conventional impregnation and ultrasonic vibration. The phase composition, surface morphology, porosity, permeability of PTFE emulsion into the coating, wear and corrosion resistance

In the combustion chambers of gas turbine engines, ZrO2-8wt.%Y2O3 (YSZ) TBCs are commonly applied by air plasma spray (APS) using Ar-/H2-based plasmas via legacy torches. Alternatively, N2/H2 plasmas could be used with the potential of increasing overall deposition efficiency (DE) and hence reduce the consumption of high-value feedstock powder. Also, by increasing DE, spraying time would be reduced

Magnesium is a suitable material for structural and aerospace applications owing to its high strength to weight ratio, yet the wide usage of Mg alloys is restricted due to their poor corrosion and mechanical properties. In this study, cold gas spraying method was used to produce pure Al, Al-Al2O3 and Al-Al2O3-CNTs coatings with feedstock powder containing Al admixed with 5 wt.% Al2O3 and 1 wt.% CNTs

Elemental diffusion drives the microstructure development in the MCrAlY-superalloy systems at high temperature. In this paper, two diffusion models were built to simulate the diffusion behavior of elements in the coating or in the coating–substrate system. Firstly, a core–shell model was set up to investigate the thermodynamic and kinetic behavior of the localized microstructure. The results of the

Biofilm-associated infections and the lack of successful tissue integration of biomaterial surfaces are the two main barriers to the long-term service of implanted biomaterials. Development of novel biocompatible antimicrobial materials has provided insights into their potential biomedical applications. Many clinical studies have successfully proved that hydroxyapatite coating has excellent osteogenic

In this study, a composite coating with outstanding corrosion and wear resistance was successfully produced on LA43M substrates. The composite coating was composed of cold-sprayed aluminum, anodized Al2O3 and a SiO2 sealing coating, which was defined as the MAC composite coating. The properties of the MAC composite coating were characterized by water contact angle, potentiodynamic polarization, salt

The low-dielectric inorganic adhesive is an important component of electromagnetic wave absorption coatings due to impedance matching with the atmospheric environment. Herein, high-enthalpy atmospheric plasma spraying (HE-APS) equipment is utilized to prepare Y2O3 ceramic coatings, and the influence of spraying power on dielectric and physical properties of Y2O3 ceramic coatings is systematically investigated

Induction heating cold spray has recently been proposed as a new hybrid additive manufacturing technique and a possible solution to avoid the delamination of soft material coatings from hard substrates. This process relies on the combined contributions of substrate preheating and in situ coating heating as a result of the alternating electromagnetic field applied that generates eddy currents. However

Cold spray (CS) is a solid-state additive manufacturing process that can create high-density, high-performance deposits for many applications. Aluminum alloys have been the target of recent CS research due to their excellent mechanical behavior when cold-sprayed. The introduction of new Al alloys to CS is of interest as unique properties may be achieved, especially when powder is heat-treated prior

It was published that zirconate coatings containing Gd/Yb and yttria-stabilized zirconia (YSZ) coatings with high Y content had good calcium-magnesium-aluminum-silicate (CMAS) corrosion resistance. However, there are few reports on CMAS resistance of zirconia-based thermal barrier coatings (TBCs) doped with Y, Gd and Yb. This article intends to explore the role of Y, Gd and Yb in resisting CMAS corrosion

Magnesium (Mg) alloys have a high strength/weight ratio, high dimensional stability, good machinability, and the ability to be recycled. However, their poor corrosion resistance in humid environments limits their usage for exterior aerospace components. This study aims to improve the corrosion resistance of two Mg alloys (AZ31B and AZ91) by using aluminum coatings. The latter have been deposited by

Suspension plasma spraying (SPS) enables the production of various coating microstructures with unique mechanical and thermal properties. Aeronautical manufacturers have been working for fifty years to improve the thermal barrier coating (TBC) performances in gas turbines. Commercial plasma torches with a segmented anode that are characterized by stable plasma jets should enable a better control of

This study aims to minimize the mechanical, chemical and thermal damages on the blades of a compressor used in aerospace engines by developing a superhydrophobic coating on the blade surface. In the absence of any information in open literature for the fabrication of such coatings, an one-step plasma spray process was implemented. For this, a well mixed powder of Ni and Ti was used as feedstock material

Industrialization of cold spray introduces concerns regarding the cost and time efficiency of cold spray procedures. In this work, high rate deposition of tantalum was studied computationally and experimentally. Quasi-1D multiphase fluid simulations predicted minimal effects on the bonding conditions of particles with 5% to 14% increase in powder-to-gas mass flow ratio. Experimental specimens were

Metallization of polyethylene (PE) using thermal spray techniques has proved difficult due to its low melting point and softness. In this study, metallic coatings were applied on porous polyethylene substrates using a twin wire-arc spray process. Commercially available polyethylene sheets, 3 mm in thickness, were used as substrates. Copper (Cu), aluminum (Al), and zinc (Zn) were successfully deposited

Despite the existence of several methods for production of superhydrophobic coatings from various materials, their application in harsh environments is still a great challenge. In this work, WC-Co-Cr cermet coatings were prepared by means of high velocity oxy-fuel (HVOF) spraying. WC particles dispersed in Co-Cr metallic matrix allowed to form the multi-scale surface roughness and thus to achieve hydrophobicity

There is high demand for refurbishment of damaged mechanical components in power plants. Twin-wire arc spraying (TWAS) is promising for on-site proactive maintenance. In this paper, FeCr-based coating was prepared on AISI 1020 carbon steel substrate by TWAS. The coating microstructure was characterized in terms of porosity, oxides and constituent phases. The wear behavior of the coating was evaluated

The aim of this work is to quantitatively describe the carbide loss during plasma deposition of metal carbide coatings and link it to the microstructure and performance of the as-sprayed coatings. To do this, a carbide loss index is defined. The results suggest that the microstructure and performance of such coatings can be tailored by controlling the content of carbides based on the proposed carbide

Laser cladding is widely used for feature repair and manufacturing of large structural components. However, due to processing parameters and thus energy densities variation, defects can form in laser clad materials. There is a need to understand the relationship between energy densities and cladding quality. This study therefore investigates the critical parameters in producing structural Stellite®

CMAS corrosion is one of the significant failure mechanisms for thermal barrier coatings (TBCs). In this work, the corrosion behaviors and wettability of CMAS on M-YTaO4 at 1350 °C are studied to evaluate the M-YTaO4 ceramics’ potential to replace YSZ. The results show that the contact angles of CMAS on M-YTaO4 with different time (1 min, 0.5 h, 4 h, 10 h and 24 h) are around 14.3° (14.4°14.4°, 14

Cavitation erosion is a sever wear mechanism that takes place in hydrodynamic systems. Examples are turbine vanes of hydropower plants or components of valves and pumps in hydraulic systems. Nickel-titanium shape memory alloys (NiTi) are attractive materials for cavitation-resistant coatings because of their pronounced intrinsic damping mitigating cavitation-induced erosion. In this work, NiTi coatings

Thermally sprayed coatings from the single oxides and binary compositions of the Al2O3-Cr2O3-TiO2 system show multifunctional properties. Ternary compositions are promising for further improvement in their performance. The stability of the composition during coating formation is an important issue for blended feedstock powders in order to obtain the desired properties. This work focuses on the compositional

High-pressure cold spray (HP-CS) was used to deposit aluminum onto polyetherketoneketone (PEKK) composite substrates. Aluminum powders were sprayed using N2 and He carrier gas and a bond layer (BL) of commercial-purity Al (CP Al). Dense 7075 and CP Al deposits were achieved via combinations of BL-N2, 7075/BL-N2, and 7075/BL-He. Cold spray using 7075 Al particles or using He carrier gas yielded thinner

In thermal spray, grit blasting is the standard method used to prepare the substrate surface before coating deposition. This study examines the effect of the grit blasting parameters on the residual stresses, roughness and hardness of three metal alloys with widely different mechanical properties: low-carbon steel, Ti-6Al-4V and Inconel 718. It also estimates the density of dislocations using the Williamson–Hall

The bonding of thermal-sprayed coatings largely depends on the substrate surface morphology. This study examines the effect of the substrate surface texture shapes on the adhesion strength of coatings. For that, it used plasma-sprayed Ni-based MoS2 coatings deposited on grit-blasted and laser-textured surfaces, and investigated the coating bonding strength (ASTM 633 pull-off test), and cross-sectional

The high-temperature oxidation and solid particle erosion of thermal barrier coating (TBC) system which consists of a 8 wt.% yttria-partially stabilized zirconia (YSZ) top coat and CoNiCrAlY bond coat deposited on Inconel 718 substrate via air plasma spraying (APS) process are studied experimentally. Isothermal oxidation tests of the APS-TBCs are conducted at 1050, 1100 and 1150 °C in air for up to

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Compared with their metal counterparts, the insufficient erosion resistance of polymer matrix composites (PMC) is a key issue for application in aero-engines. In this study, multilayered coatings were deposited on carbon fiber reinforced bismaleimide polymer composites using detonation spraying to improve their erosion resistance. The coatings consisted of a polymer–aluminum mixed transition layer

Cold spray is a solid-state process in which solid particles are subjected to severe plastic deformation to form a coating. The effect of naturally occurring oxides on bonding in the cold spray was investigated in this work. Deposition characteristics of copper powder with different surface oxide thicknesses on steel substrate were examined using a local pull-off test. This enables the investigation

For lightweight constructions, joining dissimilar metals is often indispensable to achieve exceptional properties. A common challenge is the bonding of steel and aluminum parts. The use of cold-sprayed coatings as a bonding agent is an innovative approach for high pressure die casting (HPDC) aluminum-steel hybrid components in order to achieve a metallurgical bonding, although it comes with high requirements

Conventional and nanostructured NiCoCrAlY coatings were deposited using the high-velocity oxy-fuel thermal spraying technique. The nanostructured NiCoCrAlY powder feedstock for the coatings was produced by the ball-milling method. The microstructures of the as-received and nanostructured powders as well as their developed coatings were investigated by x-ray diffraction, a field-emission scanning electron

As solid-state deposition technique avoiding oxidation, cold gas spraying is capable of retaining feedstock material properties in the coatings, but typically fails to build up coatings of brittle materials. Ceramic MAX phases show partial deformability in particular lattice directions and may thus successfully deposit in cold spraying. However, deformation mechanisms under high strain rate, as necessary

Hydrogen generation from renewable energy sources will play a key role in the concerted endeavor to constrain climate change. One environmentally friendly route, powered by sunlight, is the photoelectrochemical water splitting cell (PEC). This technology employs electrodes coated with thin films of semiconductor materials to capture light and generate charge carriers that directly drive the water splitting

Owing to low-temperature deposition conditions and high deposition rate, cold spray offers unique advantages in manufacturing a wide variety of metallic and composite coatings including metal matrix composites produced from physically blended powders. One of the challenges of producing composite coatings using cold spray is the deviation of coatings composition from the blended feedstock powder composition

There have been ever-growing demands for disinfection of water and air in recent years. Efficient, eco-friendly, and cost-effective methods of disinfection for pathogens are vital to the health of human beings. The photocatalysis route has attracted worldwide attention due to its highly efficient oxidative capabilities and sustainable recycling, which can be used to realize the disinfection purposes

As the number of aircraft that park in ocean environments increases, the corrosion of coatings used in their engines becomes inevitable. Previous studies have focussed on the abradability of as-sprayed seal coatings in high-speed rubbing tests with a blade. This study deals with the investigation of the effect of corrosion on the abradability of seal coatings. It uses metallographic analysis and hardness

“Thermal swing” coatings have recently been of great interest to automotive researchers for their potential to insulate internal combustion engines, reduce cooling requirements, and increase their efficiency. Plasma-sprayed yttria-stabilized zirconia, ceramics in the MgO-Al2O3-SiO2 system (cordierite, mullite, and steatite), and silicate-yttria-stabilized zirconia composite thermal barriers have been

High-enthalpy hybrid water/argon-stabilized plasma (WSP-H) torch may be used for efficient deposition of coatings from dry powders, suspensions, and solutions. WSP-H torch was used to deposit two complete thermal barrier coatings (TBCs) with multilayered top-coat. NiCrAlY was used as bond-coat and deposited on nickel-based superalloy substrates. Top-coat consisted of up to three sublayers: (i) yttria-stabilized