Effect of the initial particle size distribution on the properties of suspension plasma sprayed Al2O3–TiO2 coatings

Abstract

Elsevier Science SA Vicent, M.; Bannier, E.; Carpio, P.; Rayón Encinas, E.; Benavente Martínez, R.; Salvador Moya, MD.; Sánchez, E. (2015). Effect of the initial particle size distribution on the properties of suspension plasma sprayed Al2O3-TiO2 coatings. Surface and Coatings Technology. 268:209-215. AbstractAl 2 O 3 -TiO 2 coatings have been deposited by atmospheric plasma spraying from agglomerated nanostructured powders showing better properties than their conventional (microstructured) counterparts. These coatings can be also obtained by suspension plasma spraying however the research on suspension plasma sprayed Al 2 O 3 -TiO 2 is still scarce. Consequently, it is crucial to study the effect of the suspension characteristic on the coating properties and to optimise the deposition process.In this work, Al 2 O 3 -13wt%TiO 2 tribological coatings were successfully deposited by suspension plasma spraying from three different feedstocks: a nanometric suspension and two bimodal suspensions with different solid contents made up of titania nanoparticles and alumina submicron-sized particles. The coatings microstructure and phase composition were characterised using electronic microscopy and X-ray diffraction analysis. Moreover, nanoindentation technique was used to determine the coatings mechanical properties.The influence of the feed suspension characteristics on the final coating quality was analysed. Findings showed that similar microstructures and phases were evolved after depositing the different feedstocks. In addition suspension feedstock made up of nanoparticles resulted in a coating with better mechanical properties. However the use of submicron-sized particles in the suspension feedstocks gives rise to some technical and economic advantages in the process which should be taking into account when a SPS process is to be set up.

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

“…Therefore, the great challenge of this first part of the research addresses the preparation and stabilisation of multicomponent aqueous suspensions of submicronic particles of Y-TZP/Al2O3/SiC (referred as SAZ). The literature on the preparation and stabilisation of each of these oxides or their combinations is abundant [22,[24][25][26][27]. There is also previous research on the preparation of highly concentrated, aqueous suspensions of SiC submicronic particles [28,29].…”

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

“…However, Vicent et al demonstrated that power requirements become lower when solid loading is increased in the case of water suspension, in opposition to what occurs in ethanol suspensions [11]. Therefore, high solid loading suspension deposition is convenient in terms of energy and efficiency, so that thicker coatings can develop with less spraying passes.…”

Comparison between Suspension Plasma Sprayed and High Velocity Suspension Flame Sprayed bioactive coatings

“…The microstructures of SPS ceramics therefore frequently exhibit peculiar features, such as the co-existence of flattened lamellae together with regions made up of sintered, unmelted particles [54,56,57]. The porosity of these coatings also differs considerably from that of conventional atmospheric plasma sprayed ones.…”