Splat Morphology Research Articles

Ejection and deposition of mica suspension droplets under electric field

Inkjet printing of ceramic materials is a shaping process of interest for building micrometer-sized components. It consists of depositing droplets of colloidal inks according to a printing pattern designed to obtain a given final part. Improving the printed part properties, e.g., thermal or electrical, requires to tailor the printed material's local structure and orientation. Electric field is an efficient external stimulus to control particle orientation. A major challenge is to efficiently couple the effects of electric field and those of capillary, viscous, and evaporation phenomena occurring during inkjet printing. In this paper, the effect of an external electric field on the structuration of inkjet deposits is investigated. Suspensions of mica platelets dispersed in binary mixtures of chloroform and silicone oil are ejected on demand on a glass plate. An electric potential difference is applied by means of a set of electrodes below the glass substrate, separated by a small gap in order to maximize the electric field on the surface of the plate. A cartography of splat morphology and structuration for different inks as a function of applied field is performed. Promising experimental conditions display particle arrangement and limited splat deformation, whereas others lead to fingering. This paves the way to a novel additive shaping process by adding another smaller scale of structuration to inkjet printed parts.

Microstructure, property and high-temperature wear performance of Cr3C2-based coatings deposited by conventional and ID-HVAF spray torches: A comparative study

The durability of industrial components exposed to high temperatures can be increased by depositing high-velocity air-fuel (HVAF) sprayed Cr3C2-based coatings. The uniform embedding of wear-resistant Cr3C2 within an oxidation-resistant binder matrix allows HVAF-sprayed Cr3C2-based coatings to be widely used in high-temperature environments. However, consolidating these coatings demands an optimum particle velocity and temperature combination, primarily dependent on the spray torch design. Understanding the role of spray torch variants with altered combustion chamber and nozzle designs is essential, which might influence the coating (splat) formation mechanism and the resultant wear performance. Accordingly, Cr3C2–25NiCr and Cr3C2–30NiCrMoNb were sprayed using different HVAF torches (high-power AK06 and low-power AK05-ID (inner diameter): generate different energy (thermal + kinetic) output) to understand the role of the binder as well as the torch design. The deposited coatings were comprehensively compared based on splat morphology, microstructure, mechanical properties, room and high-temperature erosion and sliding wear behavior. Subsequently, a detailed post-wear analysis was performed to decipher the associated wear mechanism. As inferred from the results, Cr3C2–25NiCr coatings deposited through a high-power AK06 spray torch displayed preferable microstructure, properties and superior wear resistance. The study also offered new insights into HVAF-ID torch-deposited coatings.

A numerical study of thermal shrinkage influence on the impact dynamics of alumina droplets thermally sprayed on flat, grit-blasted and laser treated surfaces

Thermal spray splat morphology and its microstructure are of significance to the coating resulting properties. Depending on the material, the changes in density as the droplet solidifies during splat development and solidification could have a substantial role in the particle deformation dynamics, formation of porosity and subsequent adhesion to the flat or rough target surface.In the current study, the effect of shrinkage on the final splat shape is numerically investigated for collisions occurring under several high-speed impact conditions using the Volume-of-Fluid (VOF) method on real surface topography. This influence is also studied for the interaction of two successive impacting particles. The developed models study the splat impact, development and dynamics of heat transfer on flat, laser-patterned, grit-blasted surfaces and numerically designed features. The results of droplet material variable density cases are compared with those assuming constant density. Experimentally obtained single splat depositions are also used to validate the developed models and obtained numerical results.Findings show that micro substrate surface features lead to splat stretching, porosity and limited finger creation subsequent to improved solidification through interfacial contact area increase. Macro surface characteristics, however, lead to splashing and separation from the substrate surface driven by fluid instabilities. Irrespective of the interface topography, shrinkage processes reduce droplet spreading and accentuate splat feature discontinuities such as porosity.

Surface preparation of aluminum by atmospheric-pressure plasma jet for suspension plasma sprayed ceramic coatings

Surface preparation is a key step preceding the deposition of suspension plasma spray (SPS) coatings, a type of thermal spray coatings. This work evaluates the effect of surface preparation by atmospheric-pressure plasma jet (APPJ) treatment on the adhesion of SPS-deposited Al2O3 ceramic coatings on aluminum (Al-2024) substrates. For comparison, the substrate surfaces were also prepared by grit-blasting. Surface roughness (R) parameters and surface morphology of both grit-blasted and APPJ-treated substrates were characterized by confocal microscopy and scanning electron microscopy (SEM). In addition, surface chemistry was evaluated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Based on morphological analyses, the grit-blasted surfaces exhibit typical random peaks and valleys, whereas those subjected to APPJ treatment show self-organized patterns with multilayered and multiscale features. ATR-FTIR spectroscopy analyses also demonstrated a significant difference in surface chemistry for both surface preparation types. After the characterization of both types of prepared substrates, SPS coating was deposited on the substrates under two spray conditions. One spray condition demonstrated poor adherence of the coatings for both types of the prepared substrates; the other spray condition produced coatings with good adherence. The microstructures of the coating were evaluated for both spray conditions. The Adhesion strength of the coating was evaluated for the condition, which produced a coating with good adhesion. ASTM-C-633 pull test protocol was followed for the adhesion evaluation, and the pull test revealed significant adhesion improvements when the surface was prepared by APPJ. Improved adhesion strength was linked to the surface morphology and also to the surface chemistry of the surface prepared by APPJ. In addition, splat morphology was investigated on both grit-blasted and APPJ-treated substrates to correlate the improved adhesion.

Investigation of the morphologies of chelate flame-sprayed metal oxide splats

This paper reports an investigation of Er2O3 splats formed by metal–ethylenediaminetetraacetic acid (EDTA) complex particles that were applied onto aluminum alloy substrates by flame spraying. The splat morphologies and coating microstructures were analyzed under different conditions. The effects of the in-flight particle temperature of the carrier gases and the impact particle deposition temperature on solidification of the molten droplets were evaluated with a rotating dodecahedron stage operated at velocities of 30, 75, and 90 rpm and with different temperatures and angles of incidence. Various techniques were used to analyze the surfaces and cross sections of the splats and coatings formed under the different conditions. Most of the splats underwent transitions from disk shapes (ratio > 85 %) to irregular shapes (circularity of 0.61–0.80) with increasing rotational velocity. The spray process provided a coating with a porosity of 23.3 % at a powder flow rate of 20 g/min. The temperature reached during the chelate flame spraying (CFS) process and the condensing velocity of the deposited splat, rather than the in-flight particle temperature, were found to control the splat morphology. This synergistic condensation effect paves the way to successful deposition of high-temperature structural ceramic coatings such as Er2O3 with the CFS method.

Influence of spray parameters on particle deposition behaviour, microstructure, phase constitutions, and mechanical properties of high velocity oxy-fuel sprayed WC-Cr3C2-Co coatings

To optimise spray parameters for fabricating well-bonded and less decarburised coatings, the morphologies and cross-sectional microstructures of powders and splats, in addition to the microstructure, phase constitution, and mechanical properties of high-velocity oxy-fuel (HVOF)-sprayed WC–Cr3C2–Co coatings were systematically investigated. Significantly influenced by spray parameters, splat morphologies vary from ellipsoids to well-flattened pies with some ejectors or stripes on their periphery and a splat/substrate interface with good contact. Splat microstructures vary homogeneously from a minimal hard phase to non-uniform structures with some dense surface layers and smoothly outlined hard phases or to non-uniform structures with rough surfaces and angular hard phases. The coating microstructure evolves from a non-lamellar structure with many pores to a lamellar structure with a well-contacted interface and a smooth surface hard phase. The coatings mainly consist of the WC hard phase and a small fraction of decarburised and amorphous phases, in addition to Co, Cr3C2, Cr7C3, Cr2O3, and Cr2O5. Porosity and WC retention index vary from 0.89 ± 0.11 to 2.32 ± 1.75% and from 84.68 to 94.48%, respectively. Microhardness, elastic modulus, fracture toughness, adhesive strength, and wear rate of the coatings vary from 7.03 ± 0.64 to 11.96 ± 0.94 GPa, from 77.64 ± 13.77 to 244.73 ± 65.75 GPa, from 1.23 ± 0.1 to 2.66 ± 0.66 MPa m1/2, from 18.54 ± 1.21 to 63.84 ± 8.01 MPa, and from 1.38 ± 0.32 to 3.54 ± 0.79 × 10−2 mg/(N⋅m), respectively.

HVAF vs oxygenated HVAF spraying: Fundamental understanding to optimize Cr3C2-NiCr coatings for elevated temperature erosion resistant applications

High velocity sprayed Cr3C2-NiCr coatings are a viable solution to improve the life of power plant components and are often influenced by the choice of processing conditions. The new generation convertible high-velocity air-fuel (HVAF) process offers higher versatility to spray wide ranging particle sizes including the standard high-velocity oxy-fuel (HVOF) grade. However, the use of such oxygenated spraying termed as ‘HVAF(O)’ mode necessitates better understanding for reliable and repeatable coating. Single particle splat morphology and fracture mechanisms of HVAF and HVAF(O) sprayed Cr3C2-NiCr coatings were correlated with the microstructural features, mechanical properties and erosion performance with two different particle sizes. Among the coatings studied, HVAF(O) sprayed coarse Cr3C2-NiCr and HVAF sprayed fine Cr3C2-NiCr provided the least thermal degradation, and better mechanical properties which collectively ensured enhanced erosion performance. The overall coating performance can be attributed to the appropriate choice of process conditions and suitable particle size. In comparison with conventional HVOF process that generally induces a certain degree of thermal degradation within the hard carbides, oxygenated HVAF(O) sprayed Cr3C2-NiCr coating still retained most of the starting carbide phase with minimal thermal degradation, which resulted in superior erosion performance.

Deposition Behavior and Microstructure of Cold-Sprayed Ni-Coated Al Particles

Cold spraying is a novel technology for preparing solid-state coatings. Single Ni-coated Al particles were deposited onto different substrates by cold spraying at different accelerating gas temperatures, as well as preparing for the coatings. The influence of the accelerating gas temperature and substrate microhardness on the particle deposition deformation, microstructure, and microhardness of Ni-coated Al coatings were investigated. The results show that the embedding depth of Ni-coated Al particles into the Al substrate increased with increasing the accelerating gas temperature. However, the cold-sprayed Ni-coated Al particles did not embed into the Q235 steel substrate, and the degree of plastic deformation of the Ni-coated Al particles increased with increasing the accelerating gas temperature. Moreover, the morphology of the Ni-coated Al splat deposited onto the Q235 steel substrate at an accelerating gas temperature of 400 °C presented a flattened morphology, which was different from the nearly spherical or ellipsoidal morphology of the Ni-coated Al feedstock. Ni-coated Al coatings exhibited the same phase compositions as the feedstock powders, and the Ni and Al phases in the coatings incurred a certain plastic deformation. Compared with the Q235 steel substrate, an Al substrate with a lower microhardness is beneficial for forming the first layer coating, as well as for the formation of an intermixing structure between the Ni-coated Al coating and Al substrate. The porosity of Ni-coated Al coatings decreased and the thickness increased when increasing the gas temperature; in particular, the coating deposited onto Al substrate had the lowest porosity and the largest thickness at an accelerating gas temperature of 400 °C. Meanwhile, the microhardness of the coating deposited onto the Al substrate was higher than that deposited onto the Q235 steel substrate under the same cold spraying conditions.

Interactions between successive high-velocity impact droplets during plasma spraying

During plasma spraying , interactions between successive impacting particles/droplets are critical to the interfacial bonding properties between splats and the microstructural development of the bulk coating. The transient spreading process of two successive plasma- sprayed Ni20Cr droplets with different impacting spacing was numerically studied while the interfacial features between these two solidified splats were experimentally characterized by focused ion beam (FIB) microscope and transmission electron microscope (TEM). Droplets directly impacting onto the center of a previously deposited splat solidified quickly, inducing splashed fingers and smaller solidified grains. A higher droplet impact temperature could remelt the bottom splat and promote metallurgical bonding along the splat-splat interface more readily. For droplets impacting away from the previously solidified splat, the second molten droplet could either climb over the periphery of the previous splat inducing significant finger splashing, or spread beneath the curling-up splat modifying the solidification process. The solidification behavior of the subsequent droplet at the splat-splat interaction region played an important role in influencing the formation of inter-splat pores and grain growth. • Successive plasma-sprayed Ni20Cr droplets with different impact space were collected. • Interfacial features between two interacted droplets were observed by FIB and TEM. • Instant spreading dynamic between two successive droplets were simulated. • The second droplet solidification determined interface bonding and splat morphologies.

Development of Cavitation Erosion–Resistant Microwave Processed WC-based Cladding

In the present work, we investigated the effectiveness of microwave processing and thermal spraying for developing tungsten carbide (WC)-based erosion-resistant claddings. The microwave cladding showed a columnar structure with a well-bonded interface compared to discrete splat morphology and discontinuous interface of the thermal spray coating. The cladding showed a lower hardness (800 HV) compared to thermal spray coating (1,300 HV) and a two times higher fracture toughness due to the absence of splat boundaries and pores. The microwave cladding also showed 14 times and 10 times higher cavitation erosion resistance than thermal spray coating and SS316L substrate steel, respectively. The improved cavitation erosion resistance of the microwave cladding is explained on the basis of the optimized combination of hardness and fracture toughness. The surface of eroded cladding showed plastically deformed micropits compared to the thermal spray coatings, which showed large craters. Results show that microwave claddings can help improve the durability of engineering systems.

Effect of spraying power on the morphology of YSZ splat and micro-structure of thermal barrier coating

Yttria partially stabilized zirconia splats and their macroscopic thermal barrier coatings were prepared by atmospheric plasma spraying. And image analysis and scanning electron microscopy were adopted, together with splat as a link, to study why different pores and cracks are formed during the spraying process. It was determined that the spraying power altered the morphology of the splats, thereby affecting the macroscopic coating obtained by subsequent deposition. In the case where the power is too small, horizontal cracks and pores are more likely to occur, and when the power is too high, vertical cracks are likely to occur.

Microstructural study of HVOF sprayed Ni particles on a grit-blasted stainless-steel substrate

Ni feedstock particles were sprayed onto a grit-blasted stainless-steel substrate using the high-velocity oxy-fuel (HVOF) deposition process to analyse the flattening behaviour and bonding features of single splats on a roughly textured substrate surface. Both substrate surface features and splat morphologies were analysed through scanning electron microscopy (SEM), while cross-sectional features, including the nature of the splat-substrate interface, were characterised through focused ion beam (FIB) microscopy and transmission electron microscopy (TEM). The chemistry of both the splat and substrate were analysed by energy-dispersive X-ray spectroscopy (EDS) interfaced to both the SEM and TEM. It was observed that despite the surface roughness, fully melted splats demonstrated good flattening performance, as well as efficient bonding, with the substrate surface. Such bonding was revealed through elemental interdiffusion across the splat-substrate interface. The particle size and the location of impact on the rough surface played important roles in defining the melting state, flattening degree and, ultimately, adhesion of the particles. Fully melted splats derived from smaller feedstock particles demonstrated good flattening behaviour, comparable to that observed on polished surfaces. Such particles exhibited better bonding efficiency than the partially melted splats, which originated from relatively larger feedstock particles. The presence of residual alumina contaminants, retained after grit blasting, is also analysed and discussed.

Effect of in-flight particle behavior on the morphology of flame sprayed Er2O3 splats

The morphology and microstructure of splats impact the comprehensive capability of a new coating methodology called chelate flame spraying (CFS). This study addresses the quantitative characterization of the spread morphologies of flame sprayed Er2O3 splats directly deposited under different spray conditions on aluminum alloy substrates with a mirror finish. The influence of the in-flight particle temperature and velocity, carrier gas type, and carrier gas ratio on the solidification mechanism of molten droplets was investigated. Image analysis methods were employed to identify single splats from the morphology observed with field-emission scanning electron microscopy (FE-SEM). In addition, Er2O3 films were synthesized on an Al–Mg alloy (A5052) substrate using N2 or O2 as the carrier gas. When O2 was used as the carrier gas, 109-μm-thick films were deposited on the A5052 substrate. The cross-sectional porosity of the films was 3.8%. In contrast, films with 101-μm thickness were synthesized on the A5052 substrate when N2 was used as the carrier gas. The cross-sectional porosity of these films was 13.8%. The results showed that the carrier gas type (N2) and carrier gas ratio had a significant effect on the flattening behavior of the molten droplets. A spraying method combined with multidimensional modes is proposed to control the morphology of the splats.

Plasma sprayed alumina-yttria composite ceramic coating for electrical insulation applications

A composite ceramic coating consisting of 50:50 weight fraction of alumina (Al2O3)-yttria (Y2O3) blend was deposited as an electrically insulating topcoat on Oxygen-Free Electronic Copper (OFEC) substrates with a cermet interlayer of 30 wt% NiAl-70 wt% Al2O3 blend, both deposited by Atmospheric Plasma Spray (APS) process, and with a NiCrAlY bond coat deposited by High-Velocity Oxy-Fuel (HVOF) process for application in Direct Current (DC) conduction pump of the sodium-cooled fast reactor. The cermet interlayer in between topcoat and bond coat is beneficial for a reduction in the thermal expansion mismatch stresses and further contribute to the improvement in the thermal fatigue life of the multilayer coating system. The coated samples were subjected to a thermal fatigue cycle between 600 °C and 200 °C, simulating sodium-cooled fast reactor temperature patterns in regular operation and transient conditions. The multilayer composite ceramic coating with cermet interlayer successfully endured up to 1000 thermal cycles with no cracking, spallation, or delamination of the topcoat. Surface cross-sectional micrographs before and after the thermal cycle revealed neither significant changes in the splat and lamellae morphology nor distribution of phases, except for the densification effects. X-ray Diffraction (XRD) analysis revealed neither phase change nor the formation of any new phase upon thermal cycling. The adhesion test as per ASTM-C633 revealed that the bonding strength of the coatings lower by ~20% after thermal cycling. The insulation resistance of thermal cycled samples showed a two order reduction in the magnitude, compared to that of the as-coated samples.

Investigation of the bond coat interface topography effect on lifetime, microstructure and mechanical properties of air-plasma sprayed thermal barrier coatings

The effect of bond coat/thermal barrier coating (BC/TBC) interface topography on the lifetime of air-plasma sprayed (APS) TBCs was comprehensively investigated in the present work. A quantitative description of the interface topography was achieved by utilising multiple surface texture parameters obtained from confocal microscopy, including a newly formulated parameter, denominated as total thresholded summit area, Ssth. Thermal cycling fatigue (TCF) testing showed a clear correlation between the TBC lifetime and the interface topography, especially for the novel Ssth parameter. The topographical and microstructural analysis revealed that deposition of a TBC over tortuous BC topographies leads to a highly curved TBC splat morphology, which in turn affected the crack path configuration. Mechanical testing of as-deposited and heat-treated specimens evidenced that the aforementioned microstructural changes promoted a reduced local and global elastic moduli, effectively linking the more compliant TBC microstructures with more beneficial fracture mechanics behaviours and higher TCF lifetimes.

Microstructural evolution and bonding of HVOF sprayed Ni particles on both mild and stainless-steel substrates

In the present study, Ni powder was sprayed onto both mild and stainless-steel substrates using high-velocity oxy-fuel (HVOF) deposition to comparatively analyse the effect of substrate material properties and surface condition on splat formation. A range of microscopy techniques including scanning electron microscopy (SEM), focused ion beam (FIB) microscopy, transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDX) were employed to characterize both the splat morphologies, including their cross-sectional structure, as well as the nature of the splat-substrate interface. It was shown that the majority of the particles reached the substrate surface in a partially melted form owing to the high velocity typical in the HVOF process. Despite some splat splashing observed on the stainless-steel sample, the diffusion profiles, determined by STEM-EDX line scans, revealed evidence of elemental interdiffusion at the splat-substrate interface, suggesting metallurgical bonding in this sample. It was observed that splat morphologies, their frequency of occurrence and splat-substrate bond quality are all greatly affected by the surface condition of the substrate. These microstructural observations were correlated with the thermo-mechanical characteristics of the substrates to explain the mechanisms driving splat formation. Differences in the degree of plastic deformation of the substrates due to particle impact are also discussed.

Microstructural Characterization of HVOF-Sprayed Ni on Polished and Oxidized Stainless Steel Substrates

In the present study, microstructural analysis was carried out to investigate the effect of substrate surface chemistry on splat formation. Ni powder was sprayed onto stainless steel substrates exhibiting two different surface conditions (polished and oxidized) by high-velocity oxy-fuel (HVOF) thermal spray. X-ray photoelectron spectroscopy (XPS) was employed to investigate the chemical state of the surfaces which indicated the presence of the adsorbates on the oxidized substrate. Single splats of different morphologies from both samples were examined using a range of characterization techniques including scanning electron microscopy (SEM), focused ion beam (FIB) microscopy and transmission electron microscopy (TEM) and energy-dispersive x-ray spectroscopy (EDS) interfaced to both SEM and TEM. This provided information on the particle solidification behavior and splat formation mechanism following impact on substrates with distinct surface conditions. The results showed the effect of oxidized surface adsorbates on splat morphology, pore formation and splat–substrate interactions. These microstructural findings, aided by theoretical models, revealed that a mixture of mechanical and metallurgical bonds exists between the splats and both substrates.

Microstructure and mechanical property of high velocity oxy-fuel sprayed multimodal WC-Cr3C2–Co–Y2O3 cermet coating

To investigate the effect of Cr3C2 and Y2O3 additions on cermet coatings, agglomerated and sintered multimodal WC-10Cr3C2–12Co and WC-10Cr3C2–12Co–1Y2O3 cermet powders were deposited as new type of WC-based cermet coatings on plain carbon steel substrate by high velocity oxy-fuel flame spraying. Microstructures, phases, and mechanical properties of both WC-10Cr3C2–12Co and WC-10Cr3C2–12Co–1Y2O3 coatings were examined and compared with those of WC-12Co coating. Results showed that WC-10Cr3C2–12Co and WC-10Cr3C2–12Co–1Y2O3 cermet coatings presented homogeneous microstructures with multimodal carbide particles well distributed in binder matrix, and exhibited phases similar to the feedstock without decomposed phase. However, WC-12Co coating showed the existence of some serious decomposed phases including W2C and amorphous Co3W3C. Morphologies of individual splats on WC-Co substrate clearly demonstrated liquid–solid two phase deposition behaviors of three types of powders in which carbide particles were mainly present in solid state and Co in liquid state. Furthermore, fracture toughness, elastic modulus, and wear resistance of WC-10Cr3C2–12Co and WC-10Cr3C2–12Co–1Y2O3 coatings were found to be higher than those of WC-12Co coating owing to synergistic effects of Cr3C2, Y2O3, and multimodal carbides. Surface morphologies of worn out WC-12Co, WC-10Cr3C2–12Co, and WC-10Cr3C2–12Co–1Y2O3 coatings indicated that wear mechanism mainly included gouging and peeling off.

Multi-scale mechanical properties of Fe-based amorphous/nanocrystalline composite coating synthesized by HVOF spraying

Fe-based (Fe–Cr–B–P–C) amorphous/nanocrystalline composite coatings were synthesized by high velocity oxy-fuel (HVOF) thermal spray method with varying powder feed rates and the multi-scale wear behaviour of the coatings’ is reported here. Microstructural characterization of the composite coating envisaged the presence of embedded nanocrystalline phases in the amorphous matrix. The porosity content decreased, whereas the amorphicity of the coating increased gradually with increment in the feed rate. The combined effect of (i) splat morphology and (ii) extent of devitrification on the mechanical and tribological properties of the various coatings was investigated. Increasing the powder feed rate resulted in higher hardness of the coating, which was attributed to better inter-splat bonding and reduction in α-Fe content in the amorphous matrix of the coating due to lower extent of devitrification. Nanotribology test on a single-splat revealed increment in wear resistance at elevated feed rate due to the reduction in volume fraction of softer nanocrystalline α-Fe phases. Besides, dry sliding wear investigated the coatings’ wear behaviour on a global basis and revealed decreasing trends for both wear rate and coefficient of friction with increasing feed rate. Most importantly, the Fe-based composite coatings exhibited low wear volume during nanotribology and lower friction coefficient, low wear rate of dry sliding wear study, compared to an SS316L coating, prepared using industrially optimized parameters. The enhanced wear resistance of the composite coating compared to that of the stainless steel coating makes it an effective method of surface protection for metallic substrates.

Effects of substrate temperature on morphology of erbia films deposited by flame spraying using metal–ethylenediaminetetraacetic acid complex

The effects of the substrate temperature on the morphology of erbia films synthesized from a metal–ethylenediaminetetraacetic acid complex using flame spraying were evaluated. To begin with, we focused on the effect of substrate preheating on the thermal conductivity of the substrates. The morphology of the Er2O3 splats formed on various substrates (S50C and SUS304) preheated/precooled to different temperatures was investigated. The types of splats formed depended on the substrate used and its preheating/precooling temperature. The ratio of the disc-like splats on S50C (29–68%) and SUS304 (36–86%) increased with an increase in the preheating temperature between 0 and 100 °C. The wettabilities of different substrates (S50C, SUS304, Al–Mg alloy, and quartz) were also evaluated. Fourier transform infrared spectroscopy and thermogravimetry/differential thermal analysis measurements reveled that, ideally, deposition should be performed when no surface-adsorbed water is present on the substrate surface. Thus, it can be concluded that substrate preheating aids the deposition of erbia films synthesized from a metal–EDTA complex through flame spraying and that preheating is especially effective in the case of S50C substrates.