Compatibility study of plasma grown alumina coating with Pb–17Li under static conditions

Jamnapara, N.I.; Sree, A. Sarada; Kumar, E. Rajendra; Mukherjee, S.; Khanna, A. S.

doi:10.1016/j.jnucmat.2014.08.046

Cited by 15 publications

(2 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The points of analyses for P1 and P2 were ~ 20 µm apart and ~ 10 µm apart, respectively. In view of the the primary objective of validating electrical-insulating coating towards application in PbLi eutectic alloy, ingress depth of Pb (~ 99.32-99.38% by weight in PbLi eutectic) was considered representative in consistency with previously reported coating quali cation studies [27,33,36,49,51]. Analyses at various points corroborate Pb ingress limited to 20 µm depth for both the probes tested under test campaign-1.…”

Section: Metallographic Investigationssupporting

confidence: 71%

“…However, no reported study provides relevant long duration performance data on IR for Al 2 O 3 coated substrates to address critical issues related to MHD pressure drops and development of diagnostics, as highlighted above. Additionally, during the present study, it was repeatedly observed that the plasma assisted tempering and thermal tempering [49,52] of hot-dip aluminized SS-316L substrates resulted in an electrically conductive layer, which could be veri ed even at a macroscopic level, suggesting incomplete transformation to Al 2 O 3 . The study also resulted in substrate deformation due to hightemperature exposure.…”

Section: Experimental Methods and Materialsmentioning

confidence: 52%

See 1 more Smart Citation

Experimental investigations on electrical-insulation performance of Al2O3 coatings for high-temperature PbLi liquid-metal applications

Saraswat

Sasmal

Prajapati

et al. 2021

Preprint

View full text Add to dashboard Cite

Electrical-insulating coatings are of great importance for applications in liquid-metal breeder/coolant-based systems relevant to nuclear fusion power plants. In specific to lead-lithium eutectic (Pb-16Li), a candidate breeder material, such coatings are being actively investigated worldwide for their criticality in addressing various functionalities including, but not limited to, reduction in Magneto-Hydro Dynamics (MHD) pressure drop, corrosion resistance to structural materials and development of specific diagnostics, like two-phase detection techniques. For such applications, a candidate coating must be demonstrated for its compatibility with corrosive media, endurance towards high operational temperatures and integrity of electrical-insulation over long operational durations without substantial degradation. Further, quantitative performance assessment of coated substrates within PbLi environment over long operational durations is rendered difficult due to scarcity of relevant in-situ insulation resistance data. To address this shortfall, a preliminary experimental study was performed at Institute for Plasma research (IPR) towards application of AlPO4 bonded high-purity alumina (Al2O3) coatings on SS-316L substrates and further rigorous validation in static PbLi environment. The adopted coating process required a low-temperature heat treatment (< 430°C) and could yield average coating thicknesses in the range of ~ 100 µm – 500 µm. Coated samples were validated for their electrical insulation integrity in static PbLi over two test campaigns for continuous durations of over 700 h and 1360 h, including thermal cycling, at operational temperature in the range of 300°C-400°C. Volumetric electrical-resistivity, estimated through high-voltage insulation resistance measurements at relevant temperatures, remained of the order of 109-1011 Ω-cm without significant degradation. In-situ estimations of thermal derating factors establish good electrical-insulation characteristics after long term exposure to liquid PbLi. This paper presents details of utilized coating application methods, coating thickness estimations, liquid-metal test set-up, insulation performance and critical observations from SEM/EDX and XRD analysis on the tested samples.

show abstract

Section: Metallographic Investigationssupporting

confidence: 71%

Section: Experimental Methods and Materialsmentioning

confidence: 52%