Eddy Basuki - Academia.edu (original) (raw)

Papers by Eddy Basuki

Research paper thumbnail of STUDI PENGARUH PENAMBAHAN YTTRIUM DAN PERLAKUAN PANAS BETA TERHADAP KETAHANAN HIDROGEN PADUAN ZIRCALOY-4-0,1%Mo PADA TEMPERATUR 600°C DAN 800°C

Urania : Jurnal Ilmiah Daur Bahan Bakar Nuklir

STUDI PENGARUH PENAMBAHAN YTTRIUM DAN PERLAKUAN PANAS BETA TERHADAP KETAHANAN HIDROGEN PADUAN ZIR... more STUDI PENGARUH PENAMBAHAN YTTRIUM DAN PERLAKUAN PANAS BETA TERHADAP KETAHANAN HIDROGEN PADUAN ZIRCALOY-4-0,1%Mo PADA TEMPERATUR 600°C DAN 800°C. Energi listrik merupakan sumber energi yang banyak digunakan dan dibutuhkan oleh manusia. Sehingga kebutuhan energi listrik ini akan meningkat seiring bertambahnya jumlah populasi manusia. Pembangkit Listrik Tenaga Nuklir (PLTN) merupakan salah satu solusi dari persoalan tersebut. Salah satu komponen penting reaktor nuklir yaitu kelongsong bakar nuklir biasanya menggunakan material berupa paduan zirkonium, namun penggunaan paduan ini dalam waktu yang lama akan rentan terhadap penggetasan akibat penetrasi hidrogen. Serangkaian percobaan dilakukan untuk mengetahui pengaruh penambahan yttrium dan perlakuan panas beta terhadap ketahanan hidrogen dan sifat mekanis paduan Zircaloy-4-0,1%Mo-xY (x=0 wt%; 0,5 wt%; 1 wt%). Penambahan yttrium menyebabkan peningkatan jumlah presipitat yang diduga adalah α-Y sekaligus meningkatkan kekerasan paduan baik ...

Research paper thumbnail of Synthesis ternary zircalloy zr-1%Sn-1%Nb and zr- 1%Sn-1%Nb-1%Y for SMR structural cladding material

THE INTERNATIONAL CONFERENCE ON ADVANCED MATERIAL AND TECHNOLOGY (ICAMT) 2021

Local structure studies of magnesium titanate powders using time-resolved X-ray absorption spectr... more Local structure studies of magnesium titanate powders using time-resolved X-ray absorption spectroscopy (TRXAS) measurements

Research paper thumbnail of Effect Y addition on the microstructure and micro hardness of Zr-Mo-Cr alloy for SMR structural cladding material

THE INTERNATIONAL CONFERENCE ON ADVANCED MATERIAL AND TECHNOLOGY (ICAMT) 2021

Research paper thumbnail of Isothermal Oxidation Behavior of Ferritic Oxide Dispersion Strengthened Alloy at High Temperatures

Journal of Engineering and Technological Sciences, 2022

This paper discusses the oxidation behaviors of ODS steel alloy of Fe-16Cr-4Al-1Ni-0.4ZrO2 at 700... more This paper discusses the oxidation behaviors of ODS steel alloy of Fe-16Cr-4Al-1Ni-0.4ZrO2 at 700 ℃, 800 ℃, and 900 ℃. X-ray diffraction (XRD) as well as X-ray mapping in a scanning electron microscope were used to characterize the oxidation behavior of the samples. The rate of oxidation was measured based on the thickness of the oxide formed on the surface of the samples. Six types of oxides were identified in all ODS Fe-16Cr-4Al-1Ni-0.4ZrO2 alloy samples after the oxidation tests, dominated by Fe2O3, Fe3O4, Cr2FeO4, AlFeO3, Al2FeO4, and AlFe2O4. The oxidation kinetics of ODS Fe-16Cr-4Al-1Ni-0.4ZrO2 steel at 700, 800, and 900 ℃ followed logarithmic oxidation rate behavior.

Research paper thumbnail of Effects of Welded Microstructure on Fracture Toughness and Crack Propagation Behavior of API 5L-X65 Pipe

Fracture toughness of three diffeent zones in welded API 5L-X65, namely base metal, heat affected... more Fracture toughness of three diffeent zones in welded API 5L-X65, namely base metal, heat affected zone and center weld, were studied in conjuction with the implementation of pipeline project for natural gas transmission in western part of Indonesia. ASTM standard method has been used for fracture mechanics tests from which the curves of load in kN vs. extension in mm have directed to the application of CTOD parameter. The results of analysis showed that the HAZ had the highest CTOD value compared with that of base metal and centre weld. Fracture surface examinations using scanning electron microscope (SEM) confirm that the HAZ has ductile fracture while the centre weld and the base metal have brittle fracture. Based on fracture toughness values obtained, precrack resistant of the pipe was analysed using leak before break criterion. It was found that the centre weld is the weakest zone. The results were used to predict wheater the pipe will break or leak during the operation of the p...

Research paper thumbnail of The Antimicrobial Activity and Characterization of the Cast Titanium Copper Alloys with Variations of Copper Content

IOP Conference Series: Materials Science and Engineering, 2019

The effect of Cu addition on antimicrobial activity of Cast Ti-Cu Alloys against Staphylococcus a... more The effect of Cu addition on antimicrobial activity of Cast Ti-Cu Alloys against Staphylococcus aureus were studied. The Ti-Cu alloys were prepared with a variation of 0.5, 1, 2, 3, 4, 8 and 10 wt% of copper. Pure Ti metal was also prepared and tested as a comparison. The antibacterial was performed by killing activity test of colony forming unit (CFU) method with variation of contact time. Optical microscope observation, XRD, and the Vickers hardness test were carried out to characterize the investigated alloys. The results showed that Ti-Cu alloys were able to decrease the amount of bacteria by time. However, the activity of killing of bacteria in the varied range of Cu content did not show significantly different result. The highest bacterial kill ability in the alloy was observed in addition of 3 wt% Cu.

Research paper thumbnail of Isothermal Oxidation Behaviour of 69.5Fe-14Ni-9Al-7.5Cr Alloy at High Temperatures

International Journal of Corrosion, 2019

A series of experiments have been conducted to study the resistance of isothermal oxidation in 69... more A series of experiments have been conducted to study the resistance of isothermal oxidation in 69.5Fe-14Ni-9Al-7.5Cr (% wt) alloys with some temperature variations of 800, 900, and 1000°C and each temperature is tested for 1, 10, 50, and 150 hours. Based on the analysis conducted on the test results, it is known that the higher the oxidation temperature, the faster the oxidation rate. As for the duration of oxidation, the longer the testing time is, the smaller the weight change per unit sample area is, indicated by a sloping graph. The oxide products found in this study were Fe2O3, Fe3O4, α-Al2O3, NiO, Cr2O3, and NiCr2O4. The rate of oxidation of this alloy at each temperature follows a logarithmic equation indicating that the oxide layer formed is very thin and can protect the metal surface well. The oxidation rate constants at temperatures of 800, 900, and 1000°C are 5.15E-05, 5.57E-05, and 6.74E-05 gr.cm−2, respectively.

Research paper thumbnail of Effects of milling time on the microstructures of sintered Fe-16Cr-4Al-0.4Y2O3 ODS ferritic steel

Nanotechnology Perceptions, 2018

Effects of milling time on the microstructures of sintered Fe-16Cr-4Al-0.4Y 2 O 3 ODS ferritic st... more Effects of milling time on the microstructures of sintered Fe-16Cr-4Al-0.4Y 2 O 3 ODS ferritic steel ABSTRACT. Oxide dispersion-strengthened (ODS) ferritic steels have high microstructural stability at high temperatures and provide high creep resistance as well as resistance to swelling due to neutron radiation in nuclear reactors. Mechanical alloying is normally used to manufacture the ODS alloys for nuclear reactor components. The parameters of this process influence strongly on the microstructures and properties of the materials. This paper discusses the effect of milling time on the microstructures of Fe-16Cr-4Al-0.4Y 2 O 3 ODS ferritic steel. Planetary ball milling was used to prepare powder composites with milling times of 30, 60, 90 and 120 minutes. Sintering of composite green compacts was carried out at 800, 900, and 1000 °C. X-ray diffraction was used to characterize the phases formed in the ODS alloy. Analysis of microstructure, density and porosity of the sintered ODS ferritic steel was done using scanning electron microscopy and energy dispersive spectroscopy. It was found that milling for 60 minutes gave the lowest pore density in the sintered samples. A fully dissolved solid solution of α-Fe was found when the milling was carried out for at least 60 minutes.

Research paper thumbnail of Cyclic Oxidation of Aluminide Coated Two Phase α2-Ti3Al/γ-TiAl Alloys at 1000oC

Research paper thumbnail of Isothermal oxidation behavior of ternary Zr-Nb-Y alloys at high temperature

AIP Conference Proceedings, 2014

ABSTRACT

Research paper thumbnail of Effect of Briquette Thickness on Iron Nugget Formation in Fluxless Processing of Iron Sand Concentrate under Isothermal – Temperature Gradient Profiles

ISIJ International, 2022

Currently, electric furnaces and blast furnaces are used to process iron sand concentrate or tita... more Currently, electric furnaces and blast furnaces are used to process iron sand concentrate or titanomagnetite to produce pig iron and titanium slag. The titania content in the slag ranges from 10 to 25 mass% of blast furnaces and 30 to 35 mass% of electric furnaces. The low titania content in the slag is due to the addition of flux, some iron oxide must be retained in the slag to adjust the viscosity of the slag and the mixing of iron sand concentrate with ordinary iron ore. The low titania content in the slag makes titania extraction economically unattractive. One method to achieve high titania slag is the carbothermic reduction process without flux addition. A series of experiments have been carried out on the carbothermic reduction of cylindrical briquettes consisting of iron sand concentrate and coal under an isothermaltemperature gradient profile up to 1 380°C to produce iron nuggets separated from slag. The briquettes have a diameter of 13 mm, and the thickness varied from 2 to 18 mm. The results showed that the thickness of the briquettes significantly affected the iron recovery in the nuggets. The briquettes with 2 mm thickness showed higher iron recovery in the nugget. The study also found that the sulfur content in coal may have contributed to the formation of iron nuggets.

Research paper thumbnail of Hot Corrosion of Aluminide Coated Ti-Al-Cr-Nb-Zr-Y Intermetallic Alloys

Advanced Materials Research, 2015

Pack aluminide coatings were performed on a Ti-Al-Cr-Nb alloy doped with zirconium and yttrium ha... more Pack aluminide coatings were performed on a Ti-Al-Cr-Nb alloy doped with zirconium and yttrium having two phase of a2-Ti3Al and g-TiAl microstructure. The high activity TiAl3-based coating was developed from aluminizing process carried out at 850°C for 25 hours in a pack containing 20%-wt Al, 2%wt NH4Cl, and 78%wt Al2O3. During applications at high temperatures, the coating can degrade due to the interaction between the coated system and the environment exhibit high corrosion potentials. This study investigates the hot corrosion behavior of high-activity aluminide coated Zr-Y doped a2-Ti3Al/g-TiAlCrNb intermetallic alloy at 700°C, 800°C, and 900°C in a mixture of 90% Na2SO4 and 10% NaCl. The experimental results showed that the addition of Zr and Y in the alloy reduces significantly the hot corrosion rate of the coating as resulted from the interdiffusion of these elements from the alloy to the coatings and influence the behavior of the TiAl3-based coatings.

Research paper thumbnail of The Effect Of Aluminum Content On Properties Of TiAI Based Binary Alloys

Four alloys in Ti-AI binmy system (Ti-50AI, Ti-53AI, Ti-60AI and Ti-65AI in at.%) have been produ... more Four alloys in Ti-AI binmy system (Ti-50AI, Ti-53AI, Ti-60AI and Ti-65AI in at.%) have been produced by orc-Inclting process in a specially-designed and loca!ly-m!.defunwce. The alIa}' samples were then oxidized in air a! 900 o e/Dr 50 hours inside a ilili!fle };rn(lce. Ii; [his swdy, microstructures and phases of the alloys have been characterized using XRD (lnd SEM/EDS to link on their properties. It's identified that the present phases of Ti-50AI and Ti-53AI are ;(TiAI) + a](T(;AI) and ((TiAI) + TiAl;. Some tests such as density and hardness test were also carried out on the samples. Ti-50Al and Ti-53Al alloys hGl'e highest hardness value at HVN of 536 and 543 respectively. On the contraty, the lowest hardness was occurred at HVN of 435 and 445 on Ti-65AI and Ti-60AI respectively. While. the loyvest density value (3.80 grlcm 3) was reached on Ti-65AI. Meanwhile the highest density value (3.93 gr/cm 3) was occurred on Ti-53AI alloy. The oxidation kinetics was also studied by determining the weight gain of the alloy samples during the oxidation process. It's found that the highest oxidation rate belongs to Ti-50Al alloy with a 0,85% weight increase whereas Ti-65AI alloy has the lowest oxidation rate with only 0.65% increased weightfor the/ormation ofits oxide scales,

Research paper thumbnail of Alloys developed for high temperature applications

Alloys used for high temperatures applications require combinations of mechanical strength, micro... more Alloys used for high temperatures applications require combinations of mechanical strength, microstructural stability and corrosion/oxidation resistance. Nickel base superalloys have been traditionally the prime materials utilized for hot section components of aircraft turbine engines. Nevertheless, due to their limited melting temperatures, alloys based on intermetallic compounds, such as TiAl base alloys, have emerged as high temperature materials and intensively developed with the main aim to replace nickel based superalloys. For applications in steam power plants operated at lower temperatures, ferritic high temperature alloys still attract high attention, and therefore, development of these alloys is in progress. This paper highlights the important metallurgical parameters of high temperature alloys and describes few efforts in the development of Fe-Ni-Al based alloys containing B2-(Fe,Ni)Al precipitates, oxide dispersion strengthening (ODS) ferritic steels and titanium aluminide based alloys include important protection system of aluminide coatings.

Research paper thumbnail of Microstructure and oxidation resistance of spark plasma sintered Yttria-Zirconia ODS steels

IOP Conference Series: Materials Science and Engineering, 2019

In this experiment, the effect of Y2O3 and ZrO2 additions on the microstructure and cyclic oxidat... more In this experiment, the effect of Y2O3 and ZrO2 additions on the microstructure and cyclic oxidation resistance of 17-Cr ODS steel containing Al consolidated using spark plasma sintering method were studied. In addition, density, porosity and hardness were also observed. Four compositions of ferritic steels as Fe-17Cr-3.5Al-Ti-Y ('FP'), Fe-17Cr-3.5Al-Ti-Y-0.4Y2O3 ('FY'), Fe-17Cr-3.5Al-Ti-Y-0.4ZrO2 ('FZ'), and Fe-17Cr-3.5Al-Ti-Y-0.2Y2O3-0.2ZrO2 ('FYZ') were prepared by mechanical alloying and followed by sintering at 1000 °C. Microstructure characteristics were observed for different aspect, viz. elemental distribution, composition, and phase identification. Cyclic oxidation tests were carried out at 800 °C for 8 cycles. The results show that ZrO2 addition suppresses the formation of Y-Al-O clustering and promotes the formation of Y-Zr-O clustering and the enhancement of oxidation resistance of the alloy. However, in some condition it also has a deleterious effect on crack resistance. In contrast, the addition of Y 2O3 decreases the oxidation resistance but increases the hardness.

Research paper thumbnail of MICROSTRUCTURAL EVOLUTION OF FERRITIC STEEL Fe-14Ni-9Al-7.5Cr-1Mo STRENGTHENED BY B2-(Fe,Ni)Al AT HIGH TEMPERATURES

MICROSTRUCTURAL EVOLUTION AND COARSENING KINETICS OF B2-(Fe,Ni)Al IN FERRITIC STEEL OF Fe-14Ni-9A... more MICROSTRUCTURAL EVOLUTION AND COARSENING KINETICS OF B2-(Fe,Ni)Al IN FERRITIC STEEL OF Fe-14Ni-9Al-7,5Cr-1Mo AT HIGH TEMPERATURES. Increasing the efficiency of power plant facilities, such as steam power plant, is demanding, and this drives to the development of materials capable for higher temperature operations. Ferritic steels have been widely used for boiler components due to their relatively economical and higher in thermal conductivity. Nevertheless, the application of ferritic steels for boilers is limited only at 630 °C due to their weakness in creep strength and corrosion at higher temperatures. Efforts to increase the performance of ferritic steels at higher temperature applications have been intensively carried out, one of which is by developing B2-(Fe,Ni)Al precipitates in the ferrite matrix. This paper discusses the microstructural evolution in alloy of Fe-14Ni-9Al-7.5Cr-1Mo (in wt.%) strengthened by B2-(Fe,Ni)Al precipitates during heating at 800, 900, and 1000 C for 6...

Research paper thumbnail of Oxidation Behavior of Aluminide Coated Ti-Al-Cr-Nb-Zr-Y Alloys at High Temperatures

Solid State Phenomena, 2015

In this study the oxidation behavior of diffusion aluminide coating containing layers of TiAl3 an... more In this study the oxidation behavior of diffusion aluminide coating containing layers of TiAl3 and TiAl2, develop on a substrate of Zr-Y doped α2-Ti3Al/γ-TiAlCrNb intermetallic alloy using pack aluminizing method, was investigated isothermally at 800°C, 900°C, and 1000°C under atmospheric air pressure. The pack cementation was carried out at 850°C for 25 hours in a pack containing 20%-wt Al, 2%-wt NH4Cl, and 78%-wt Al2O3.The phases in the coatings and oxide layers were examined by optical and scanning electron microscopy as well as X-ray diffraction method, while chemical composition of the oxides and phases were examined with EDS attached on the SEM. The experimental results showed that the addition of Zr and Y increases the oxidation resistance of the coating by formation of complex oxides mainly of Al2O3 at the coating surfaces and sub-surface. Combination of oxidation and interdiffusion process cause transformation of TiAl3 layer to TiAl2 that decrease the oxidation resistance t...

Research paper thumbnail of High Temperature Oxidation of Zr-2.5%wt Nb Alloys Doped with Yttrium

Journal of Materials Science and Engineering B, Dec 28, 2013

Zirconium base alloys have been utilized in LWRs (light water reactors) as fuel element cladding ... more Zirconium base alloys have been utilized in LWRs (light water reactors) as fuel element cladding tubes, fuel assembly spacer grids, guide tubes in PWRs (pressurized water reactors) due to their low neutron absorption and good corrosion resistance. The oxidation resistance of Zr alloys are strongly controlled by the phase presence and composition of the alloys. The beneficial effect of yttrium content on isothermal oxidation behavior of Zr-2.5%Nb-Y(Y = 0, 0.5, 1, 1.5)in wt % alloy at high temperature has been studied. High temperature oxidation carried out in air furnace at 600,700 and 800 o C for 1, 4, and 9 h. Characterization by optical microscope showed that microstructure of Zr-2.5%Nb-Y alloys relatively unchanged. X-ray diffraction of the alloys depicted that the oxide scale formed during oxidation of zirconium alloys is monoclinic ZrO 2 and minor of tetragonal ZrO 2 , while unoxidized alloy showed two phase  and  phase. SEM-EDS examination shows that depletion of Zr composition took place under the oxide layer. Kinetic rate of oxidation of zirconium alloy showed that increasing oxidation temperature will increase oxidation rate but increasing yttrium content in the alloys will decrease oxidation rate. The parabolic rate constant value decreasing with increasing yttrium in Zr-2.5%Nb alloys.

Research paper thumbnail of Interdiffusion Behavior of Aluminide Coated Two-Phase α2-Ti3Al/γ-TiAl Alloys at High Temperatures

Journal of Engineering and Technological Sciences

Lower density materials of TiAl based intermetallic alloys have recently attracted intensive atte... more Lower density materials of TiAl based intermetallic alloys have recently attracted intensive attention for the replacement of nickel-based superalloys used at high temperatures. As aluminium-rich titanium aluminide intermetallic compounds are normally brittle, two-phase α 2-Ti 3 Al/γ-TiAl alloys have been developed. To increase the corrosion resistance of these alloy systems, an aluminide coating of TiAl 3 layer is normally applied. During operation at high temperatures, however, interdiffusion between the coating and the alloy substrate can occur and decrease the TiAl 3 layer thickness of the coating. The effects of temperature exposure on the growth of the TiAl 2 interdiffusion zone layer on two-phase α 2-Ti 3 Al/γ-TiAl alloys with a chemical composition of Ti-47Al-2Nb-2Cr-0.5Y-0.5Zr are presented in this paper. The exponents for kinetics and rate constant of the TiAl2 interdiffusion layer growth of this multi-component system were found under variation of temperature. The results were compared with those from other researchers.

Research paper thumbnail of Improving hot corrosion resistance of two phases intermetallic alloy α2-Ti3Al/γ-TiAl with enamel coating

Co-based alloys design based on first-principles calculations: Influence of transition metal and ... more Co-based alloys design based on first-principles calculations: Influence of transition metal and rare-earth alloying element on stacking fault energy AIP Conference Proceedings 1805, 060004 (2017);

Research paper thumbnail of STUDI PENGARUH PENAMBAHAN YTTRIUM DAN PERLAKUAN PANAS BETA TERHADAP KETAHANAN HIDROGEN PADUAN ZIRCALOY-4-0,1%Mo PADA TEMPERATUR 600°C DAN 800°C

Urania : Jurnal Ilmiah Daur Bahan Bakar Nuklir

STUDI PENGARUH PENAMBAHAN YTTRIUM DAN PERLAKUAN PANAS BETA TERHADAP KETAHANAN HIDROGEN PADUAN ZIR... more STUDI PENGARUH PENAMBAHAN YTTRIUM DAN PERLAKUAN PANAS BETA TERHADAP KETAHANAN HIDROGEN PADUAN ZIRCALOY-4-0,1%Mo PADA TEMPERATUR 600°C DAN 800°C. Energi listrik merupakan sumber energi yang banyak digunakan dan dibutuhkan oleh manusia. Sehingga kebutuhan energi listrik ini akan meningkat seiring bertambahnya jumlah populasi manusia. Pembangkit Listrik Tenaga Nuklir (PLTN) merupakan salah satu solusi dari persoalan tersebut. Salah satu komponen penting reaktor nuklir yaitu kelongsong bakar nuklir biasanya menggunakan material berupa paduan zirkonium, namun penggunaan paduan ini dalam waktu yang lama akan rentan terhadap penggetasan akibat penetrasi hidrogen. Serangkaian percobaan dilakukan untuk mengetahui pengaruh penambahan yttrium dan perlakuan panas beta terhadap ketahanan hidrogen dan sifat mekanis paduan Zircaloy-4-0,1%Mo-xY (x=0 wt%; 0,5 wt%; 1 wt%). Penambahan yttrium menyebabkan peningkatan jumlah presipitat yang diduga adalah α-Y sekaligus meningkatkan kekerasan paduan baik ...

Research paper thumbnail of Synthesis ternary zircalloy zr-1%Sn-1%Nb and zr- 1%Sn-1%Nb-1%Y for SMR structural cladding material

THE INTERNATIONAL CONFERENCE ON ADVANCED MATERIAL AND TECHNOLOGY (ICAMT) 2021

Local structure studies of magnesium titanate powders using time-resolved X-ray absorption spectr... more Local structure studies of magnesium titanate powders using time-resolved X-ray absorption spectroscopy (TRXAS) measurements

Research paper thumbnail of Effect Y addition on the microstructure and micro hardness of Zr-Mo-Cr alloy for SMR structural cladding material

THE INTERNATIONAL CONFERENCE ON ADVANCED MATERIAL AND TECHNOLOGY (ICAMT) 2021

Research paper thumbnail of Isothermal Oxidation Behavior of Ferritic Oxide Dispersion Strengthened Alloy at High Temperatures

Journal of Engineering and Technological Sciences, 2022

This paper discusses the oxidation behaviors of ODS steel alloy of Fe-16Cr-4Al-1Ni-0.4ZrO2 at 700... more This paper discusses the oxidation behaviors of ODS steel alloy of Fe-16Cr-4Al-1Ni-0.4ZrO2 at 700 ℃, 800 ℃, and 900 ℃. X-ray diffraction (XRD) as well as X-ray mapping in a scanning electron microscope were used to characterize the oxidation behavior of the samples. The rate of oxidation was measured based on the thickness of the oxide formed on the surface of the samples. Six types of oxides were identified in all ODS Fe-16Cr-4Al-1Ni-0.4ZrO2 alloy samples after the oxidation tests, dominated by Fe2O3, Fe3O4, Cr2FeO4, AlFeO3, Al2FeO4, and AlFe2O4. The oxidation kinetics of ODS Fe-16Cr-4Al-1Ni-0.4ZrO2 steel at 700, 800, and 900 ℃ followed logarithmic oxidation rate behavior.

Research paper thumbnail of Effects of Welded Microstructure on Fracture Toughness and Crack Propagation Behavior of API 5L-X65 Pipe

Fracture toughness of three diffeent zones in welded API 5L-X65, namely base metal, heat affected... more Fracture toughness of three diffeent zones in welded API 5L-X65, namely base metal, heat affected zone and center weld, were studied in conjuction with the implementation of pipeline project for natural gas transmission in western part of Indonesia. ASTM standard method has been used for fracture mechanics tests from which the curves of load in kN vs. extension in mm have directed to the application of CTOD parameter. The results of analysis showed that the HAZ had the highest CTOD value compared with that of base metal and centre weld. Fracture surface examinations using scanning electron microscope (SEM) confirm that the HAZ has ductile fracture while the centre weld and the base metal have brittle fracture. Based on fracture toughness values obtained, precrack resistant of the pipe was analysed using leak before break criterion. It was found that the centre weld is the weakest zone. The results were used to predict wheater the pipe will break or leak during the operation of the p...

Research paper thumbnail of The Antimicrobial Activity and Characterization of the Cast Titanium Copper Alloys with Variations of Copper Content

IOP Conference Series: Materials Science and Engineering, 2019

The effect of Cu addition on antimicrobial activity of Cast Ti-Cu Alloys against Staphylococcus a... more The effect of Cu addition on antimicrobial activity of Cast Ti-Cu Alloys against Staphylococcus aureus were studied. The Ti-Cu alloys were prepared with a variation of 0.5, 1, 2, 3, 4, 8 and 10 wt% of copper. Pure Ti metal was also prepared and tested as a comparison. The antibacterial was performed by killing activity test of colony forming unit (CFU) method with variation of contact time. Optical microscope observation, XRD, and the Vickers hardness test were carried out to characterize the investigated alloys. The results showed that Ti-Cu alloys were able to decrease the amount of bacteria by time. However, the activity of killing of bacteria in the varied range of Cu content did not show significantly different result. The highest bacterial kill ability in the alloy was observed in addition of 3 wt% Cu.

Research paper thumbnail of Isothermal Oxidation Behaviour of 69.5Fe-14Ni-9Al-7.5Cr Alloy at High Temperatures

International Journal of Corrosion, 2019

A series of experiments have been conducted to study the resistance of isothermal oxidation in 69... more A series of experiments have been conducted to study the resistance of isothermal oxidation in 69.5Fe-14Ni-9Al-7.5Cr (% wt) alloys with some temperature variations of 800, 900, and 1000°C and each temperature is tested for 1, 10, 50, and 150 hours. Based on the analysis conducted on the test results, it is known that the higher the oxidation temperature, the faster the oxidation rate. As for the duration of oxidation, the longer the testing time is, the smaller the weight change per unit sample area is, indicated by a sloping graph. The oxide products found in this study were Fe2O3, Fe3O4, α-Al2O3, NiO, Cr2O3, and NiCr2O4. The rate of oxidation of this alloy at each temperature follows a logarithmic equation indicating that the oxide layer formed is very thin and can protect the metal surface well. The oxidation rate constants at temperatures of 800, 900, and 1000°C are 5.15E-05, 5.57E-05, and 6.74E-05 gr.cm−2, respectively.

Research paper thumbnail of Effects of milling time on the microstructures of sintered Fe-16Cr-4Al-0.4Y2O3 ODS ferritic steel

Nanotechnology Perceptions, 2018

Effects of milling time on the microstructures of sintered Fe-16Cr-4Al-0.4Y 2 O 3 ODS ferritic st... more Effects of milling time on the microstructures of sintered Fe-16Cr-4Al-0.4Y 2 O 3 ODS ferritic steel ABSTRACT. Oxide dispersion-strengthened (ODS) ferritic steels have high microstructural stability at high temperatures and provide high creep resistance as well as resistance to swelling due to neutron radiation in nuclear reactors. Mechanical alloying is normally used to manufacture the ODS alloys for nuclear reactor components. The parameters of this process influence strongly on the microstructures and properties of the materials. This paper discusses the effect of milling time on the microstructures of Fe-16Cr-4Al-0.4Y 2 O 3 ODS ferritic steel. Planetary ball milling was used to prepare powder composites with milling times of 30, 60, 90 and 120 minutes. Sintering of composite green compacts was carried out at 800, 900, and 1000 °C. X-ray diffraction was used to characterize the phases formed in the ODS alloy. Analysis of microstructure, density and porosity of the sintered ODS ferritic steel was done using scanning electron microscopy and energy dispersive spectroscopy. It was found that milling for 60 minutes gave the lowest pore density in the sintered samples. A fully dissolved solid solution of α-Fe was found when the milling was carried out for at least 60 minutes.

Research paper thumbnail of Cyclic Oxidation of Aluminide Coated Two Phase α2-Ti3Al/γ-TiAl Alloys at 1000oC

Research paper thumbnail of Isothermal oxidation behavior of ternary Zr-Nb-Y alloys at high temperature

AIP Conference Proceedings, 2014

ABSTRACT

Research paper thumbnail of Effect of Briquette Thickness on Iron Nugget Formation in Fluxless Processing of Iron Sand Concentrate under Isothermal – Temperature Gradient Profiles

ISIJ International, 2022

Currently, electric furnaces and blast furnaces are used to process iron sand concentrate or tita... more Currently, electric furnaces and blast furnaces are used to process iron sand concentrate or titanomagnetite to produce pig iron and titanium slag. The titania content in the slag ranges from 10 to 25 mass% of blast furnaces and 30 to 35 mass% of electric furnaces. The low titania content in the slag is due to the addition of flux, some iron oxide must be retained in the slag to adjust the viscosity of the slag and the mixing of iron sand concentrate with ordinary iron ore. The low titania content in the slag makes titania extraction economically unattractive. One method to achieve high titania slag is the carbothermic reduction process without flux addition. A series of experiments have been carried out on the carbothermic reduction of cylindrical briquettes consisting of iron sand concentrate and coal under an isothermaltemperature gradient profile up to 1 380°C to produce iron nuggets separated from slag. The briquettes have a diameter of 13 mm, and the thickness varied from 2 to 18 mm. The results showed that the thickness of the briquettes significantly affected the iron recovery in the nuggets. The briquettes with 2 mm thickness showed higher iron recovery in the nugget. The study also found that the sulfur content in coal may have contributed to the formation of iron nuggets.

Research paper thumbnail of Hot Corrosion of Aluminide Coated Ti-Al-Cr-Nb-Zr-Y Intermetallic Alloys

Advanced Materials Research, 2015

Pack aluminide coatings were performed on a Ti-Al-Cr-Nb alloy doped with zirconium and yttrium ha... more Pack aluminide coatings were performed on a Ti-Al-Cr-Nb alloy doped with zirconium and yttrium having two phase of a2-Ti3Al and g-TiAl microstructure. The high activity TiAl3-based coating was developed from aluminizing process carried out at 850°C for 25 hours in a pack containing 20%-wt Al, 2%wt NH4Cl, and 78%wt Al2O3. During applications at high temperatures, the coating can degrade due to the interaction between the coated system and the environment exhibit high corrosion potentials. This study investigates the hot corrosion behavior of high-activity aluminide coated Zr-Y doped a2-Ti3Al/g-TiAlCrNb intermetallic alloy at 700°C, 800°C, and 900°C in a mixture of 90% Na2SO4 and 10% NaCl. The experimental results showed that the addition of Zr and Y in the alloy reduces significantly the hot corrosion rate of the coating as resulted from the interdiffusion of these elements from the alloy to the coatings and influence the behavior of the TiAl3-based coatings.

Research paper thumbnail of The Effect Of Aluminum Content On Properties Of TiAI Based Binary Alloys

Four alloys in Ti-AI binmy system (Ti-50AI, Ti-53AI, Ti-60AI and Ti-65AI in at.%) have been produ... more Four alloys in Ti-AI binmy system (Ti-50AI, Ti-53AI, Ti-60AI and Ti-65AI in at.%) have been produced by orc-Inclting process in a specially-designed and loca!ly-m!.defunwce. The alIa}' samples were then oxidized in air a! 900 o e/Dr 50 hours inside a ilili!fle };rn(lce. Ii; [his swdy, microstructures and phases of the alloys have been characterized using XRD (lnd SEM/EDS to link on their properties. It's identified that the present phases of Ti-50AI and Ti-53AI are ;(TiAI) + a](T(;AI) and ((TiAI) + TiAl;. Some tests such as density and hardness test were also carried out on the samples. Ti-50Al and Ti-53Al alloys hGl'e highest hardness value at HVN of 536 and 543 respectively. On the contraty, the lowest hardness was occurred at HVN of 435 and 445 on Ti-65AI and Ti-60AI respectively. While. the loyvest density value (3.80 grlcm 3) was reached on Ti-65AI. Meanwhile the highest density value (3.93 gr/cm 3) was occurred on Ti-53AI alloy. The oxidation kinetics was also studied by determining the weight gain of the alloy samples during the oxidation process. It's found that the highest oxidation rate belongs to Ti-50Al alloy with a 0,85% weight increase whereas Ti-65AI alloy has the lowest oxidation rate with only 0.65% increased weightfor the/ormation ofits oxide scales,

Research paper thumbnail of Alloys developed for high temperature applications

Alloys used for high temperatures applications require combinations of mechanical strength, micro... more Alloys used for high temperatures applications require combinations of mechanical strength, microstructural stability and corrosion/oxidation resistance. Nickel base superalloys have been traditionally the prime materials utilized for hot section components of aircraft turbine engines. Nevertheless, due to their limited melting temperatures, alloys based on intermetallic compounds, such as TiAl base alloys, have emerged as high temperature materials and intensively developed with the main aim to replace nickel based superalloys. For applications in steam power plants operated at lower temperatures, ferritic high temperature alloys still attract high attention, and therefore, development of these alloys is in progress. This paper highlights the important metallurgical parameters of high temperature alloys and describes few efforts in the development of Fe-Ni-Al based alloys containing B2-(Fe,Ni)Al precipitates, oxide dispersion strengthening (ODS) ferritic steels and titanium aluminide based alloys include important protection system of aluminide coatings.

Research paper thumbnail of Microstructure and oxidation resistance of spark plasma sintered Yttria-Zirconia ODS steels

IOP Conference Series: Materials Science and Engineering, 2019

In this experiment, the effect of Y2O3 and ZrO2 additions on the microstructure and cyclic oxidat... more In this experiment, the effect of Y2O3 and ZrO2 additions on the microstructure and cyclic oxidation resistance of 17-Cr ODS steel containing Al consolidated using spark plasma sintering method were studied. In addition, density, porosity and hardness were also observed. Four compositions of ferritic steels as Fe-17Cr-3.5Al-Ti-Y ('FP'), Fe-17Cr-3.5Al-Ti-Y-0.4Y2O3 ('FY'), Fe-17Cr-3.5Al-Ti-Y-0.4ZrO2 ('FZ'), and Fe-17Cr-3.5Al-Ti-Y-0.2Y2O3-0.2ZrO2 ('FYZ') were prepared by mechanical alloying and followed by sintering at 1000 °C. Microstructure characteristics were observed for different aspect, viz. elemental distribution, composition, and phase identification. Cyclic oxidation tests were carried out at 800 °C for 8 cycles. The results show that ZrO2 addition suppresses the formation of Y-Al-O clustering and promotes the formation of Y-Zr-O clustering and the enhancement of oxidation resistance of the alloy. However, in some condition it also has a deleterious effect on crack resistance. In contrast, the addition of Y 2O3 decreases the oxidation resistance but increases the hardness.

Research paper thumbnail of MICROSTRUCTURAL EVOLUTION OF FERRITIC STEEL Fe-14Ni-9Al-7.5Cr-1Mo STRENGTHENED BY B2-(Fe,Ni)Al AT HIGH TEMPERATURES

MICROSTRUCTURAL EVOLUTION AND COARSENING KINETICS OF B2-(Fe,Ni)Al IN FERRITIC STEEL OF Fe-14Ni-9A... more MICROSTRUCTURAL EVOLUTION AND COARSENING KINETICS OF B2-(Fe,Ni)Al IN FERRITIC STEEL OF Fe-14Ni-9Al-7,5Cr-1Mo AT HIGH TEMPERATURES. Increasing the efficiency of power plant facilities, such as steam power plant, is demanding, and this drives to the development of materials capable for higher temperature operations. Ferritic steels have been widely used for boiler components due to their relatively economical and higher in thermal conductivity. Nevertheless, the application of ferritic steels for boilers is limited only at 630 °C due to their weakness in creep strength and corrosion at higher temperatures. Efforts to increase the performance of ferritic steels at higher temperature applications have been intensively carried out, one of which is by developing B2-(Fe,Ni)Al precipitates in the ferrite matrix. This paper discusses the microstructural evolution in alloy of Fe-14Ni-9Al-7.5Cr-1Mo (in wt.%) strengthened by B2-(Fe,Ni)Al precipitates during heating at 800, 900, and 1000 C for 6...

Research paper thumbnail of Oxidation Behavior of Aluminide Coated Ti-Al-Cr-Nb-Zr-Y Alloys at High Temperatures

Solid State Phenomena, 2015

In this study the oxidation behavior of diffusion aluminide coating containing layers of TiAl3 an... more In this study the oxidation behavior of diffusion aluminide coating containing layers of TiAl3 and TiAl2, develop on a substrate of Zr-Y doped α2-Ti3Al/γ-TiAlCrNb intermetallic alloy using pack aluminizing method, was investigated isothermally at 800°C, 900°C, and 1000°C under atmospheric air pressure. The pack cementation was carried out at 850°C for 25 hours in a pack containing 20%-wt Al, 2%-wt NH4Cl, and 78%-wt Al2O3.The phases in the coatings and oxide layers were examined by optical and scanning electron microscopy as well as X-ray diffraction method, while chemical composition of the oxides and phases were examined with EDS attached on the SEM. The experimental results showed that the addition of Zr and Y increases the oxidation resistance of the coating by formation of complex oxides mainly of Al2O3 at the coating surfaces and sub-surface. Combination of oxidation and interdiffusion process cause transformation of TiAl3 layer to TiAl2 that decrease the oxidation resistance t...

Research paper thumbnail of High Temperature Oxidation of Zr-2.5%wt Nb Alloys Doped with Yttrium

Journal of Materials Science and Engineering B, Dec 28, 2013

Zirconium base alloys have been utilized in LWRs (light water reactors) as fuel element cladding ... more Zirconium base alloys have been utilized in LWRs (light water reactors) as fuel element cladding tubes, fuel assembly spacer grids, guide tubes in PWRs (pressurized water reactors) due to their low neutron absorption and good corrosion resistance. The oxidation resistance of Zr alloys are strongly controlled by the phase presence and composition of the alloys. The beneficial effect of yttrium content on isothermal oxidation behavior of Zr-2.5%Nb-Y(Y = 0, 0.5, 1, 1.5)in wt % alloy at high temperature has been studied. High temperature oxidation carried out in air furnace at 600,700 and 800 o C for 1, 4, and 9 h. Characterization by optical microscope showed that microstructure of Zr-2.5%Nb-Y alloys relatively unchanged. X-ray diffraction of the alloys depicted that the oxide scale formed during oxidation of zirconium alloys is monoclinic ZrO 2 and minor of tetragonal ZrO 2 , while unoxidized alloy showed two phase  and  phase. SEM-EDS examination shows that depletion of Zr composition took place under the oxide layer. Kinetic rate of oxidation of zirconium alloy showed that increasing oxidation temperature will increase oxidation rate but increasing yttrium content in the alloys will decrease oxidation rate. The parabolic rate constant value decreasing with increasing yttrium in Zr-2.5%Nb alloys.

Research paper thumbnail of Interdiffusion Behavior of Aluminide Coated Two-Phase α2-Ti3Al/γ-TiAl Alloys at High Temperatures

Journal of Engineering and Technological Sciences

Lower density materials of TiAl based intermetallic alloys have recently attracted intensive atte... more Lower density materials of TiAl based intermetallic alloys have recently attracted intensive attention for the replacement of nickel-based superalloys used at high temperatures. As aluminium-rich titanium aluminide intermetallic compounds are normally brittle, two-phase α 2-Ti 3 Al/γ-TiAl alloys have been developed. To increase the corrosion resistance of these alloy systems, an aluminide coating of TiAl 3 layer is normally applied. During operation at high temperatures, however, interdiffusion between the coating and the alloy substrate can occur and decrease the TiAl 3 layer thickness of the coating. The effects of temperature exposure on the growth of the TiAl 2 interdiffusion zone layer on two-phase α 2-Ti 3 Al/γ-TiAl alloys with a chemical composition of Ti-47Al-2Nb-2Cr-0.5Y-0.5Zr are presented in this paper. The exponents for kinetics and rate constant of the TiAl2 interdiffusion layer growth of this multi-component system were found under variation of temperature. The results were compared with those from other researchers.

Research paper thumbnail of Improving hot corrosion resistance of two phases intermetallic alloy α2-Ti3Al/γ-TiAl with enamel coating

Co-based alloys design based on first-principles calculations: Influence of transition metal and ... more Co-based alloys design based on first-principles calculations: Influence of transition metal and rare-earth alloying element on stacking fault energy AIP Conference Proceedings 1805, 060004 (2017);