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Isothermal oxidation performance of Laser Cladding Assisted with Preheat (LCAP) tribaloy T-800 composite coatings deposited on EN8

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dc.contributor.author Nyadongo, Sipiwe Trinity
dc.contributor.author Pityana, Sisa Lesley
dc.contributor.author Olakanmi, Eyitayo Olatunde
dc.date.accessioned 2021-09-23T10:37:27Z
dc.date.available 2021-09-23T10:37:27Z
dc.date.issued 2021-07-13
dc.identifier.citation Nyadongo, S. T., Pityana, S. L. and Olakanmi, E. O. (2021) Isothermal oxidation performance of laser cladding assisted with preheat (LCAP) tribaloy T-800 composite coatings deposited on EN8. Coatings, 11(7), 843. https://doi.org/10.3390/coatings11070843 en_US
dc.identifier.issn 2079-6412
dc.identifier.uri http://repository.biust.ac.bw/handle/123456789/351
dc.description.abstract It is anticipated that laser cladding assisted with preheat (LCAP)-deposited Tribaloy (T-800) composite coatings enhances resistance to structural degradation upon exposure to elevated-temperature oxidation service environments. The oxidation kinetics of LCAP T-800 composite coatings deposited on EN8 substrate and its mechanisms have not been explored in severe conditions that are similar to operational parameters. The isothermal oxidation behaviour of the T-800 composite coating deposited on EN8 via LCAP was studied at 800 °C in air for up to 120 h (5 × 24 h cycles) and contrasted to that of uncoated samples. The mass gain per unit area of the coating was eight times less than that of the uncoated EN8 substrate. The parabolic rate constant (Kp) for EN8 was 6.72 × 10−12 g2·cm−4·s−1, whilst that for the T-800 composite coating was 8.1 × 10−13 g2·cm−4·s−1. This was attributed to a stable chromium oxide (Cr2O3) layer that formed on the coating surface, thereby preventing further oxidation, whilst the iron oxide film that formed on the EN8 substrate allowed the permeation of the oxygen ions into the oxide. The iron oxide (Fe2O3) film that developed on EN8 spalled, as evidenced by the cracking of oxide when the oxidation time was greater than 72 h, whilst the Cr2O3 film maintained its integrity up to 120 h. A parabolic law was observed by the T-800 composite coating, whilst a paralinear law was reported for EN8 at 800 °C up to 120 h. This coating can be used in turbine parts where temperatures are <800 °C en_US
dc.description.sponsorship African Laser Centre (ALC) under Grant No. CSIR-NLC Reference LHIL 500 task ALC R014 together with Research Initiation Fund (Grant No. BIUST/ds/r&I/7/2016) provided by Botswana International University of Science and Technology. en_US
dc.language.iso en en_US
dc.publisher MDPI (Basel.Switzerland) en_US
dc.subject High-temperature oxidation en_US
dc.subject Laser cladding assisted with preheat (LCAP) en_US
dc.subject Tribaloy T-800 composite en_US
dc.subject EN8 steel en_US
dc.subject Coating en_US
dc.title Isothermal oxidation performance of Laser Cladding Assisted with Preheat (LCAP) tribaloy T-800 composite coatings deposited on EN8 en_US
dc.description.level phd en_US
dc.description.accessibility unrestricted en_US
dc.description.department mie en_US


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