Build-up mechanism of suspension plasma-sprayed alumina coatings deposited by WSP-H plasma torch.

0484134 - ÚFP 2018 RIV BE eng C - Conference Paper (international conference)
Tesař, Tomáš - Mušálek, Radek - Medřický, Jan
Build-up mechanism of suspension plasma-sprayed alumina coatings deposited by WSP-H plasma torch.
SMT31 Conference Proceedings: International Conference on Surface Modification Technologies (SMT 31). Mons: University of Mons, UMONS, 2017. SMT, 31. ISBN N.
[SMT31: International Conference on Surface Modification Technologies 2017. Mons (BE), 05.07.2017-07.07.2017]
R&D Projects: GA ČR GA15-12145S
Institutional support: RVO:61389021
Keywords : suspension plasma spraying * microstructure * build-up * alumina * splat
OECD category: Coating and films

Suspension plasma spraying is a modification of the conventional plasma spraying, where dry coarse powder is replaced by suspension of fine powder. SPS method benefits from using of high enthalpy plasma torches, since additional heat is necessary to evaporate the liquid carrier. This paper elucidates the growth mechanisms of the suspension plasma sprayed coatings prepared by high enthalpy WSP-H plasma torch. Two alumina suspensions with different formulation were sprayed to demonstrate different build-up mechanisms of the coatings with typical “cauliflower-like” and dense microstructures. Splat formation, particle trajectory divergence, and spray beads were investigated and it was demonstrated that the mutual sample-torch position also strongly influences the character of the coating. Moreover, it was observed that cauliflower-like columnar structure may be, developed also on smooth surfaces and the typical column diameter is directly connected to the thickness of the coating.
Permanent Link: http://hdl.handle.net/11104/0279301