Effect of particle size distribution of suspension feedstock on the microstructure and mechanical properties of suspension plasma spraying YSZ coatings

Abstract

Estimation of the length of the manuscript (the pages of the manuscript should be numbered) Number of words Please fill outPlease fill out Length of the text 1) (using "word count") 3716 Number of Tables 1 × 150 3) Total number of words: 4000 words for a contributed paper (oral and posters), 8000 words for an invited paper and plenary paper. Manuscripts exceeding these word limits will not be considered for publication in the Proceedings volume. These too long papers could be submitted to the Editor of the journal for publication as regular papers. AbstractIn this work, aqueous suspensions feedstocks with different particle size distribution from submicron-and nano-sized YSZ powders were prepared. A previous colloidal characterisation allowed concentrated suspensions (~40 wt%) to be prepared. These suspensions were then successfully deposited by suspension plasma spraying (SPS) onto stainless steel substrates at different spraying distances. Coatings were characterised in terms of microstructure and mechanical properties (hardness and elastic modulus) by nanoindentation.All coatings displayed a two-zones microstructure formed by partially molten melted areas containing nanometer or submicrometer-sized particles surrounded by fully molten melted areas. These partially molten melted areas strongly increased as standoff distance lengthened. Mechanical properties worsened with spraying distance increase.The finer the feedstock particle size the more the spraying distance effect was. A clear correlation between mechanical properties and amount of partially molten melted areas has been proved. Thus the use of a mixture of nano/submicron-sized particles as a SPS feedstock can represent a good balance between suspension processability and final coating performance.

Aqueous suspension processing of multicomponent submicronic Y-TZP/Al 2 O 3 /SiC particles for suspension plasma spraying

“…3b. The isoelectric point occurs at pH6, in good agreement with previously reported values [30][31][32]. The addition of 0.2 wt% PAA shifts down the iep to pH 3 and provides large values of zeta potential at neutral pH (-60 mV at pH 6).…”

“…Besides, a filter with a mesh of 75 µm was placed before the injector to avoid clogging by agglomerates. This system has been set out in previous research [25,32]. AISI 304 stainless steel disks, with a diameter of 25 mm and 10 mm of thickness, were employed as substrates.…”

Alumina-zirconia coatings obtained by suspension plasma spraying from highly concentrated aqueous suspensions

“…A plasma torch (F4-MB, Oerlikon Metco, Germany) operated by an industrial robot (IRB 1400, ABB, Switzerland) was adapted in order to spray suspensions by mechanical injection assisted by air pressure with a maximum pressure of 6 bar. More details about SPS adaptation have been described in a previous work [21]. In this study, suspensions inside a vessel were agitated by a magnetic stirrer to avoid possible sedimentation and a viscosity rise in the case of thixotropic suspensions.…”

Estudio de la estructura y las propiedades mecánicas en un recubrimiento de circona estabilizada con 8% en mol de itria elaborado por proyección térmica por plasma a partir de suspensiones

“…En ambos estudios los recubrimientos mostraron una estructura bimodal formada por partículas nanométricas rodeadas por lamelas completamente fundidas, lo que causó una distribución bimodal de las propiedades (dureza y módulo de elasticidad). Otro trabajo como el de Carpio et al [15], estudió la influencia de las materias primas en suspensión acuosa con una distribución de tamaño de partícula submicrométrica y nanométrica en las propiedades mecá-nicas de recubrimientos de YSZ elaborados por SPS. Así encontró que mediante nanoindentación, todos los recubrimientos muestran una estructura formadas por zonas parcialmente fundidas que contienen partículas de tamaño submicrométrico rodeadas de zonas completamente fundidas.…”