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Nur Farhana Hayazi
Preferred name
Nur Farhana Hayazi
Official Name
Nur Farhana, Hayazi
Alternative Name
Hayazi, Nur Farhana
Hayazi, N.F
Nur Farhana Hayazi
Main Affiliation
Scopus Author ID
55899042500
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1 - 3 of 3
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PublicationOxide growth behaviour of 800H and HR-120 series ni-based alloys on isothermal oxidation( 2024-03)
;Nurul Athirah Zainal @ Zaiton ; ;Aqmar Ikhmal Anuar ;The isothermal oxidation of two types of Ni-based alloy, alloys 800H and HR-120 was investigated in this study. The alloy underwent an isothermal oxidation test at 950 ºC for 150 hours of exposure. Oxdised alloys were tested using oxidation kinetics methods, phase analysis using X-ray diffraction (XRD) and oxide morphology using scanning electron microscopy (SEM) techniques. Oxidation kinetics were determined based on the weight change per surface area of the oxidised alloy over a 30-hour interval. As a result, both alloys displayed a pattern of weight gain as the exposure period increased. Both alloys have followed a parabolic rate law, indicating a controlled kinetics of oxide scale diffusion. XRD analysis showed that the main Cr-containing oxide has formed on the surface of the alloy with the addition of Ti oxide for the 800H alloy and Nb oxide for the HR-120 alloy due to the different alloying element content of the two alloys. Oxide surface morphology records the uniform oxide scale that forms on the surface of the alloy.17 2 -
PublicationInvestigation of corrosion behaviour of mild steel embedded in geopolymer paste with curing and non-curing process(Polish Academy of Sciences, 2023)
;Fatin Shahira Shaharudin ; ; ; ; ;Sri HastutyAndri KusbiantoroThis research was conducted to examine the corrosion behaviour of mild steel bar embedded in geopolymer paste based fly ash Class F during curing and non-curing process. The geopolymer paste was fabricated by blending in the fly ash with alkaline activators (NaOH solution with molarity of 12 M, 2.5 ratio of solution Na2SiO3/NaOH). The paste was produced in 50 mm × 50 mm × 50 mm mould where the mild steel bar of 100 mm (length) × 12 mm (diameter) was embedded at the center of geopolymer paste. This is to comprehend the corrosion behaviour of mild steel embedded in geopolymer paste with and without curing process. Process of curing is carried out for 24 hours at a temperature of 60°C in oven. While on the contrary, the non-curing process will only be leave at room temperature. Both samples were tested after 28 days of curing to determine the corrosion behaviour, phase analysis and morphology analysis. In accordance with the morphology analysis, it shows that the fly ash was totally reacted with alkaline solutions in curing geopolymer paste sample while the non-curing geopolymer paste has shown the unreacted fly ash with high number of pores. The phase analysis of mild steel embedded in this geopolymer paste during curing and without curing process has proven that the presence of new crystallographic peak which also known as passive layer occurred. The potential values result by OCP testing shows the curing sample has highest potential values as compared to the non-curing sample ones.14 1 -
PublicationEffect of primer layer and curing method on geopolymer paste coating properties( 2024-12)
; ;Jie Xin See ; ;Sri HastutyThis technical paper presents a comprehensive study on the properties of geopolymer coating applied to mild steel pipelines as a potential alternative to Ordinary Portland cement (OPC) concrete structures. The geopolymer paste was formulated using a mixture of fly ash and alkaline activators, specifically sodium hydroxide (NaOH) solution and sodium silicate (Na2SiO3) solution. Two types of primers, epoxy metal primer and self-etch primer were applied before the geopolymer coating and various curing conditions were investigated. The geopolymer samples were subjected to two different curing processes: one set was cured in an oven at 60°C for 24 hours while the other set was left to cure under ambient conditions. After the curing period, the samples were aged at ambient conditions for 28 days. The properties of the fly ash and geopolymer paste were evaluated through a range of tests including phase analysis, morphology analysis, optical emission spectroscopy (OES) analysis, chemical composition analysis and adhesion strength testing. The results revealed that the geopolymer coatings exhibited surface cracks and efflorescence attributed to unreacted sodium oxide. X-Ray diffraction (XRD) analysis confirmed the presence of quartz, hematite, magnetite, aluminum oxide and mullite in the geopolymer coating. The self-etch primercoated samples demonstrated improved adhesion and corrosion resistance properties with a denser and more cohesive microstructure. The geopolymer coating when applied with a self-etch primer and cured at 60°C for 2 hours, achieved the highest adhesion strength of 2.2 MPa, indicating strong bonding with the mild steel pipelines. These findings contribute to the understanding of geopolymer coatings and their potential application in enhancing the performance and durability of mild steel pipelines, offering a sustainable alternative to conventional concrete coatings with improved corrosion resistance and adhesion properties.2 18