The influence of substrate temperature and spraying distance on the properties of plasma sprayed tungsten and steel coatings deposited in a shrouding chamber

0476705 - ÚFP 2018 RIV CH eng J - Journal Article
Matějíček, Jiří - Vilémová, Monika - Nevrlá, Barbara - Kocmanová, Lenka - Veverka, Jakub - Halasová, Martina - Hadraba, Hynek
The influence of substrate temperature and spraying distance on the properties of plasma sprayed tungsten and steel coatings deposited in a shrouding chamber.
Surface and Coatings Technology. Roč. 318, May (2017), s. 217-223. ISSN 0257-8972.
[International Meeting on Thermal Spraying (RIPT)/7./. Limoges, 09.12.2015-11.12.2015]
R&D Projects: GA ČR GB14-36566G
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021 ; RVO:68081723
Keywords : Tungsten * Steel * Atmospheric plasma spraying * Shrouding * Substrate temperature * Fusion reactor materials * Plasma facing components
OECD category: Coating and films; Coating and films (UFM-A)
Impact factor: 2.906, year: 2017
http://www.sciencedirect.com/science/article/pii/S0257897216310520

Plasma spraying is among the alternative technologies for manufacturing tungsten-based coatings or graded interlayers for plasma facing components of fusion devices. The main limitation lies in the relatively low thermal conductivity, stemming from the anisotropic porosity and imperfect bonding between the splats. For several materials, it has been shown that increased substrate temperature leads to improved intersplat bonding and increased coating density. However, spraying of metals at elevated temperatures in ambient atmosphere is accompanied by enhanced oxidation.
This work is focused on the effects of substrate temperature on the properties of plasma sprayed tungsten and steel coatings. A range of substrate temperatures was achieved by varying the preheating temperature, pauses between torch passes, spraying distance and intensity of cooling. To suppress oxidation, the substrates were placed in a special shrouding chamber flushed with argon-hydrogen mixture. The coatings were characterized for their structure, porosity, hardness, thermal conductivity and oxygen content. A marked improvement of these properties with substrate temperature was observed and correlated to the spraying parameters.
Permanent Link: http://hdl.handle.net/11104/0273166