Structure of Plasma-Sprayed Zirconia Coatings Tailored by Controlling the Temperature and Velocity of the Sprayed Particles

Prystay, M.; Gougeon, P.; Moreau, Christian

doi:10.1361/105996301770349529

Cited by 73 publications

(33 citation statements)

References 7 publications

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“…These temperatures are much higher than that of the melting point of titania (1855°C) [20]. Therefore, these results seem to agree with those of Prystay et al [30].…”

Section: Through-thickness Crack Network Formationsupporting

confidence: 92%

“…Therefore, one of the possible ways to generate an increased vertical-to-horizontal microcrack ratio is via thermal spraying particles at high temperatures to (i) produce higher levels of quenching stress within each splat, by improving the splat/ underlying surface bonding via the lowering of particle viscosity, (ii) reduce the surface area of the horizontal pores and cracks, leading to an enhanced splat contact adherence and thermal conductivity and (iii) increasing the deposition rate. Prystay et al [30] were able to tailor horizontally and vertically oriented crack distributions in zirconia coatings deposited via APS by controlling the temperature and velocity of the sprayed particles. It was observed that to produce higher amounts of vertically oriented cracks, the generation of high particle temperatures was a key issue.…”

Section: Through-thickness Crack Network Formationmentioning

confidence: 99%

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Towards engineering isotropic behaviour of mechanical properties in thermally sprayed ceramic coatings

Lima

Kruger

Marple

2008

Surface and Coatings Technology

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It is widely recognized by the scientific community that thermal spray coatings exhibit anisotropic behaviour of mechanical properties, e.g., the elastic modulus values of the coating in-plane (i.e., parallel to the substrate surface) or through-thickness (i.e., perpendicular to the substrate surface) will tend to be significantly different due to their anisotropic microstructures. This work shows that thermally sprayed ceramic coatings may exhibit isotropic mechanical behaviour similar to that of bulk materials even when exhibiting the typical anisotropic coating microstructure. Elastic modulus values on the in-plane and through-thickness directions were measured via Knoop indention and laser-ultrasonic techniques on a coating produced via flame spray (FS) using a nanostructured titania (TiO 2 ) powder. No significant differences were found between the coating directions. In addition, four major cracks with similar lengths were observed originating near or at the corners of Vickers indentation impressions on the coating cross-section (i.e., a typical characteristic of bulk ceramics), instead of two major cracks propagating parallel to the substrate surface, which is normally the case for these types of coatings. It was observed by scanning electron microscopy (SEM) that coatings tended to exhibit an isotropic behaviour when the average length of microcracks within the coating structure oriented perpendicular to the substrate surface was about twice that of the microcracks aligned parallel to the substrate surface. Modelling, based on scalar crack densities of horizontal and vertical cracks, was also used to estimate when thermal spray coatings tend to exhibit isotropic behaviour. Crown

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“…These temperatures are much higher than that of the melting point of titania (1855°C) [20]. Therefore, these results seem to agree with those of Prystay et al [30].…”

Section: Through-thickness Crack Network Formationsupporting

confidence: 92%

Section: Through-thickness Crack Network Formationmentioning

confidence: 99%

Towards engineering isotropic behaviour of mechanical properties in thermally sprayed ceramic coatings

Lima

Kruger

Marple

2008

Surface and Coatings Technology

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“…Prystay et al [1] reported similar values for internally injected plasma-sprayed YSZ. The inverse relationship between YSZ temperature and velocity, and the overall lower temperatures and higher velocities for YAG can be understood in terms of dwell-time.…”

Section: Temperature and Velocity Relationshipmentioning

confidence: 75%

“…In this process, powder is injected into a high-velocity, high-temperature plasma flame and propelled toward a substrate. The feedstock powder can be injected internally [1,2] (inside the nozzle exit) or externally [3][4][5] (outside the nozzle exit). Regardless of the injection manner, the molten or semimolten particles spread on the substrate surface are rapidly quenched, and form "splats" on impact.…”

Section: Introductionmentioning

confidence: 99%

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In Situ Characterization of Small-Particle Plasma Sprayed Powders

Su¹,

Bernecki

Faber³

2002

Journal of Thermal Spray Technology

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The effect of various small-particle plasma spray powder injection parameters on the in situ particle position, velocity, and temperature is measured for yttria-stabilized zirconia and yttrium-aluminum-garnet powder. Using full-factorial experiments and multiple regression analysis, carrier gas flow, injector angle, and powder feeder disc speed were found to significantly affect the particle properties. Temperature and velocity were inversely related; on average, the cooler particles traveled faster. These properties also correlated to the particle position in the flame, where particles above the centerline of the flame traveled faster. The trends are discussed on the basis of residence time in the flame, as well as in terms of particle size segregation effects. Coating density and splat geometry reflect the temperature and velocity differences between the runs. Slower, hotter particles possessed more intrasplat and intersplat porosity and less splat-substrate contact area, leading to lower overall coating density.

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Effect of Injection Parameters on Velocity and Temperature Distributions of Alumina‐Titania In‐Flight Particles in Atmospheric Plasma Spraying

2004

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cutting proceeded perpendicular to the carbon fiber fabrics using a cemented carbide drilling tool. The analysis of the tool temperatures were conducted by varying the cutting parameters.The effects of process temperatures on the machining results and on the cutting process itself were studied. In this connection, several non-reinforced and reinforced polymer materials such as poly ether ether ketone and epoxy resin were machined. In addition, glass fiber reinforced as well as carbon short fiber reinforced composites have been examined.

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Structure of Plasma-Sprayed Zirconia Coatings Tailored by Controlling the Temperature and Velocity of the Sprayed Particles

Cited by 73 publications

References 7 publications

Towards engineering isotropic behaviour of mechanical properties in thermally sprayed ceramic coatings

Towards engineering isotropic behaviour of mechanical properties in thermally sprayed ceramic coatings

In Situ Characterization of Small-Particle Plasma Sprayed Powders

Effect of Injection Parameters on Velocity and Temperature Distributions of Alumina‐Titania In‐Flight Particles in Atmospheric Plasma Spraying

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