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Noraziana Parimin
Preferred name
Noraziana Parimin
Official Name
Noraziana, Parimin
Alternative Name
Parimin, N.
Noraziana, Parimin
Main Affiliation
Scopus Author ID
55955288500
Researcher ID
GCS-3360-2022
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1 - 4 of 4
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PublicationCharacterization of oxidation kinetics and oxide scale formation on isothermal oxidation of HR-120 ni-based superalloy at 500ºC( 2024-12)
;Esah HamzahAstuty AmrinThe HR-120 Ni-based superalloy underwent isothermal oxidation at 500°C in order to better understand the oxidation kinetics and the production of oxide scales. To create small and large grain structure, the HR-120 Ni-based superalloy was heat-treated at two distinct temperatures, 950ºC and 1100ºC. A 500°C for 500 h isothermal oxidation test was performed on the heat-treated alloy of the study examined the oxidation kinetics, oxide phase development and oxide surface morphology of alloy that had undergone isothermal xidation. Plotting weight gain versus surface area allowed for the measurement of oxidation kinetics. The XRD method was used to examine the oxide phase. Surface morphology was investigated with SEM and EDX methods. A parabolic rate law was observed in the oxidation of both heat-treated alloys, suggesting a diffusion-controlled oxide growth mechanism. The alloy’s surface has developed many oxide phases as a result of exposures lasting 500 h. The oxidized samples’ surface morphology after 300 hours shows that overly large Nb-rich oxides are dispersed throughout the continuous oxide scale development. On coarse-grained heat-treated alloys, Nb-rich oxides produced that were abnormally big. This occurrence will initiate a crack that spreads around the oxide. -
PublicationIsothermal oxidation behaviour of heat-treated Fe-33Ni-19Cr series ni-based superalloy( 2024-12)
;Megat Farhan Nazmi Megat Mohamad HalimEsah HamzahThe impact of heat treatment on the high temperature oxidation of Ni-based superalloys, specifically the Fe-33Ni-19Cr series, is discussed in this study. This alloy, designated LT950 and HT1160, is heat treated at two distinct temperatures, 950 °C and 1150 °C, for three hours of soaking time, followed by a water quench. Rockwell hardness tests and optical microscopy were used to characterize the heat-treated samples. An isothermal oxidation test was performed on the heat-treated samples for 200 hours at 900 °C. The oxidation kinetics were ascertained by measuring the weight change of the oxidized sample. Oxidized samples were characterized by morphological analysis of the oxide scale using a scanning electron microscope (SEM) and oxide phase analysis using x-ray diffraction (XRD). As a result, the sample's grain size increases with increasing heat treatment temperature. The results of the Rockwell hardness test indicate that the Rockwell hardness number decreases as the heat treatment temperature rises. However, every heat-treated sample that was put through the isothermal oxidation test displayed a pattern of weight gain as the length of exposure increased. Because fine-grained LT950 has a lower parabolic rate constant, it indicates a lower rate of oxidation and therefore has good resistance to oxidation. XRD analysis shows that several oxide layers have formed on the surface of the oxidized sample consisting of Cr-containing oxides from the Cr2O3 and MnCr2O4 phases. SEM analysis of fine-grained LT950 showed uniform oxide scale, while coarse-grained HT1150 showed the formation of cracked and porous structures. -
PublicationInfluence of solution treatment temperature on the microstructure of Ni-based HR-120 superalloyThe solution treatment process has been carried out on Ni-based HR-120 superalloy (Fe-40Ni-24Cr) at six different temperatures, namely 950ºC, 1000ºC, 1050ºC, 1100ºC, 1150ºC and 1200ºC. All samples were soaking for 3 hours at desired temperature, followed by water quench. The main objective of the solution treatment process is to vary the grain size of the alloy. The effect of solution treatment process on the alloy has been investigated in term of microstructure, grain size, phase present and hardness test, by using optical microscope, scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) spectrometer, x-ray diffraction (XRD) technique and Vickers hardness test. As a results, the grain size of the solution-treated alloy were increase as the solution treatment temperature increase from 27.27 μm to 40.86 μm for solution-treated alloy at 950ºC to 1200ºC, respectively. Three precipitate phases were detected during phase analysis which are NbC, TiC and (Nb,Ti)C on the solution-treated alloy. In addition, as the grain size increase when the solution treatment temperature increase, the hardness value was decrease.
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PublicationOxide growth behaviour of Fe-Ni-Cr alloy at high temperature oxidationThe isothermal oxidation test has been investigated on two types of Fe-Ni-Cr alloy, namely Fe-33Ni-19Cr and Fe-40Ni-24Cr alloys. Both alloys were undergoing an isothermal oxidation test at temperature of 500? for 500 hours exposure time. The weight change per surface area of the oxidized samples has been recorded to calculate the oxidation kinetics of both alloys. The oxide growth behaviour of oxidized samples has been examined using scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) spectrometer. The oxide phase formed on the sample surface has been analyzed using x-ray diffraction (XRD) technique. The results show that both alloys were followed a parabolic rate law, indicating a diffusion-controlled oxide growth mechanism. In addition, the oxidation kinetics indicating an increasing weight gain trend as the exposure time increase. Several oxide phases had formed on the oxidized surface of both alloys, consists of Cr-rich, Ti-rich, Fe-rich and spinel oxide structure. The surface morphology of both alloys demonstrated a continuous oxide scale formed on the alloy surface. Additionally, Fe-33Ni-19Cr alloy recorded a formation of Ti-rich oxide, whereas, Fe-40Ni-24Cr alloy displayed a formation of overgrown Nb-rich oxide particle which. Roles of the precipitates in oxidation mechanism give new insights into the alloy optimization.