Browsing by Author "Abdullah, T.K"

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    Investigation of Al2O3-Modified Aluminide on 304SS: Microstructural Evolution, Hardness and Growth Kinetics through Slurry Aluminizing
    (Published by Trans Tech Publications, 2024-12-20) AMBALI IBRAHIM OWOLABI; Tan, S.M; Jalaluddin, M.A; Anasyida, A.S; Abdullah, T.K; Dhindaw,B.K
    The alumina alumina alumina alumina alumina microstructure microstructure microstructure microstructure microstructure microstructure microstructure microstructure microstructure microstructure microstructure microstructure 2O3)- aluminide aluminide aluminide aluminide aluminide coating were investigated at 650℃, 680℃, and 700℃ for various durations (4, 6, 8, 10 hours) using the slurry aluminizing process. The coating were investigated at 650℃, 680℃, and 700℃ for various durations (4, 6, 8, 10 hours) using the slurry aluminizing process. The coating were investigated at 650℃, 680℃, and 700℃ for various durations (4, 6, 8, 10 hours) using the slurry aluminizing process. The coating were investigated at 650℃, 680℃, and 700℃ for various durations (4, 6, 8, 10 hours) using the slurry aluminizing process. The coating were investigated at 650℃, 680℃, and 700℃ for various durations (4, 6, 8, 10 hours) using the slurry aluminizing process. The modifiedwere investigated at 650℃, 680℃, and 700℃ for various durations (4, 6, 8, and 10 hours) using the slurry aluminizing process. The heat-treated heat-treated heat-treated heat-treated -treated samples samples samples samples samples samples were were were analyzed analyzed analyzed analyzed through through through through through through through scanning scanning scanning scanning scanning scanning electron microscopy (SEM), energy dispersive spectroscopy EDS), and X-ray diffraction XRD) to assess microstructural evolution, elemental composition, phases of the coating. SEM electron microscopy (SEM), energy dispersive spectroscopy EDS), and X-ray diffraction XRD) to assess microstructural evolution, elemental composition, phases of the coating. SEM electron microscopy (SEM), energy dispersive spectroscopy EDS), and X-ray diffraction XRD) to assess microstructural evolution, elemental composition, phases of the coating. SEM electron microscopy (SEM), energy dispersive spectroscopy EDS), and X-ray diffraction XRD) to assess microstructural evolution, elemental composition, phases of the coating. SEM electron microscopy (SEM), energy dispersive spectroscopy EDS), and X-ray diffraction XRD) to assess microstructural evolution, elemental composition, phases of the coating. SEM microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) to assess microstructural evolution, elemental composition, and phases of the coating. SEM observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and Fe-FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with between 610 700 HV. The growth kinetics indicated the thickness of layers increased both aluminizing temperature time, following observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and Fe-FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with between 610 700 HV. The growth kinetics indicated the thickness of layers increased both aluminizing temperature time, following observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and Fe-FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with between 610 700 HV. The growth kinetics indicated the thickness of layers increased both aluminizing temperature time, following observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and Fe-FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with between 610 700 HV. The growth kinetics indicated the thickness of layers increased both aluminizing temperature time, following observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and Fe-FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with between 610 700 HV. The growth kinetics indicated the thickness of layers increased both aluminizing temperature time, following observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and Fe-FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with between 610 700 HV. The growth kinetics indicated the thickness of layers increased both aluminizing temperature time, following observations revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and Fe-FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with between 610 700 HV. The growth kinetics indicated the thickness of layers increased both aluminizing temperature time, following revealed a two-layer aluminide coating, comprising an Al-rich intermetallic (FeAl3) and a Fe-rich intermetallic (FeAl). Microhardness tests showed that FeAl3 had hardness values ranging from 880 to 990 HV, while FeAl, with values between 610 and 700 HV. The growth kinetics indicated that the thickness of the aluminide layers increased with both the aluminizing temperature and time, following a parabolic growth law. The activation energy for the of FeAl was 343.15 kJ/mol.
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    Microstructural evolution and hardness properties of Si-modified aluminide coating on 304 stainless steel via slurry aluminizing: effect of aluminizing temperatures
    (Published by the Universiti Putra Malaysia, Malaysia, 2024-06-16) AMBALI IBRAHIM OWOLABI; Anasyida A. S; Abdullah, T.K
    Surface modification of austenitic steel with a Si-modified aluminide coating enhances its lifespan by improving resistance to corrosion, oxidation, and high-temperature strength. To achieve this, a slurry composed of silicon, alumina, and aluminium was applied on the surface of 304 stainless steel (304SS) substrates. The samples were subjected to aluminizing at 750 °C, 800 °C, and 850 °C for 6 hours. Microstructural analysis was carried out using a field scanning electron microscope (FESEM) equipped with energy-dispersed X-ray spectroscopy (EDX), while X-ray diffraction (XRD) was employed for phase identification. The hardness of the coating was measured using Vicker microhardness. The study revealed the presence of various binary intermetallic compounds, including Fe2Al5, Fe3Al, and FeAl, as well as ternary phases like Al3Fe2Si3 and Fe1.7Al4Si, within the coatings. The addition of silicon reduced the intermetallic compound (IMC) layer thickness by occupying vacancy sites along the crystal structure c-axis of Fe2Al5, thereby restraining the growth of this brittle IMC in favor of more ductile phases. Notably, specimens heat treated at 850 °C exhibited the highest thickness of Fe-Al IMC layers. As temperature increases, the number of voids at the interface between the aluminide layer and the steel substrate also grew. Microhardness measurement revealed that Fe2Al5, FeAl, and Fe3Al layers had a hardness value of about 850-990 HV, 570-630 HV, and 320-410 HV respectively for all the temperatures. Fe2Al5 has the lowest toughness and is confirmed to be the hardest zone in the aluminide coating. Si-modified aluminide coatings on 304 stainless steels could be considered as a material candidate for high temperature application.