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METODE ARITMETIKA FORMULA BRAGG PADA PENGKAJIAN STRUKTUR KRISTAL BAJA SUPERALOI TIPE F1, A2 DAN A2-APS. Yunasz, Iing Farihin (Parikin); Dani, Mohammad; Sugeng, Bambang; Permatasari, Novita Dwi; Ahda, Syahfandi; Sukaryo, Sulistioso Giat
Majalah Ilmiah Pengkajian Industri Vol 12, No 3 (2018): MAJALAH ILMIAH PENGKAJIAN INDUSTRI
Publisher : BPPT

Perekayasa material BATAN telah berhasil mensintesis serial baja superaloi tipe Austenitik (A2) dan tipe Feritik (F1). Beberapa bahan telah dilakukan treatments dengan memvariasi waktu penyinaran menggunakan arc plasma sintering (APS). Dalam studi ini dilakukan pengukuran difraksi sinar-X untuk menginvestigasi bentuk bangun struktur kristal dan parameter kisi dari baja feritik F1, baja austenitik A2 dan baja austenitik A2 yang disintering APS selama 2 detik penyinaran. Perhitungan dilakukan menggunakan formula Bragg dengan membandingkan deret aritmetika (hitung) S2 dan jarak interplanar dhkl. Diketahui bahwa: baja feritik F1 berstruktur body centered cubic (BCC) dengan parameter kisi a = 2,87 Å. Baja austenitik A2 berstruktur face centered cubic (FCC) dengan parameter kisi a = 3,59 Å. Baja austenitik A2 yang disintering APS selama 2 detik berstruktur face centered cubic (FCC) dengan parameter kisi a = 3,60 Å. Pengamatan struktur mikro permukaan bahan menggunakan Mikroskop Optik (OM) dan Mikroskop Elektron (SEM) memperlihatkan mikrografi yang menarik. Mengasumsikan kondisi proses peleburan (casting) sama, kedua tipe bahan uji memiliki struktur cor yang mirip. Baja feritik F1 menampakkan batas butir (grain boundary) yang lebih halus jika dibandingkan dengan batas butir dalam baja austenitik A2 yang cenderung terlihat lebar garis batasnya. Sedang baja austenitik A2 yang disintering APS selama 2 detik, menampakkan pola butiran yang semula memanjang berubah struktur butiran (grain)-nya menjadi agak bulat-bulat (globular). Uji SEM memetakan sebaran presipitat pada baja feritik F1 di batas butir dan di dalam butir, sedangkan pada baja autenitik A2 tersebar di batas butir saja. Spektrum EDX menunjukkan komposisi presipitat pada baja feritik F1 meliputi C, Cr, dan Fe. Sedangkan pada baja austenitik A2: C, Cr, Fe, dan Ni. Dimungkinkan, krom karbida (Cr23C6) terbentuk sebagai precipitat di batas butir, karena bahan didominanasi konten unsur Cr dan C.Kata Kunci : feritik F1, austenitik A2, XRD, aritmetika, formula Bragg, struktur mikro.

Thermal Properties Investigation of FeCr Alloy Using Lammps Simulation: A Preliminary Study Panitra, Mardiyanto Mangun; Ahda, Syahfandi; Rivai, Abu Kahlid
Majalah Ilmiah Pengkajian Industri Vol 13, No 2 (2019): Majalah Ilmiah Pengkajian Industri
Publisher : BPPT

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29122/mipi.v13i2.3401

At present, nuclear reactor technology that is widely used because of its proven reliability is the gen-III + nuclear reactor. Even if it is seen from the aspect of safety and reliability of this generation reactor, it has been proven, but because nuclear energy plays a vital role to meet the growing world energy needs, it is necessary to have a type of nuclear reactor that is tailored to those needs.The next generation of nuclear reactors must meet the requirements of fulfilling safety requirements, be flexible, a longer operating life (more than 60 years), more economical. In order for a reactor to produce higher power, a longer operating life and more economical, reactor structure materials which are capable of being operated at high temperatures are needed. The types of materials that are expected to meet these requirements include various types of ferritic / martensite steel, austenite, alloy steel containing nickel, and metal glass materials and ceramic materials. FeCr metal alloys are alloys that form the metals mentioned above, so it is important to conduct research both in simulation and experiment. Molecular Dynamics simulation of FeCr alloys using Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) has been done to explore their thermodynamic characteristics such as heat treatment, solubility of Cr, atomic radial distribution function (RDF). The results of the simulation are illustrated using Visual Molecular Dynamics (VMD) code.

THERMAL PROPERTIES INVESTIGATION OF FECR ALLOY USING LAMMPS SIMULATION: A PRELIMINARY STUDY Panitra, Mardiyanto Mangun; Ahda, Syahfandi; Rivai, Abu Kahlid
Majalah Ilmiah Pengkajian Industri Vol 13, No 2 (2019): Majalah Ilmiah Pengkajian Industri
Publisher : BPPT

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29122/mipi.v13i2.3401

At present, nuclear reactor technology that is widely used because of its proven reliability is the gen-III + nuclear reactor. Even if it is seen from the aspect of safety and reliability of this generation reactor, it has been proven, but because nuclear energy plays a vital role to meet the growing world energy needs, it is necessary to have a type of nuclear reactor that is tailored to those needs.The next generation of nuclear reactors must meet the requirements of fulfilling safety requirements, be flexible, a longer operating life (more than 60 years), more economical. In order for a reactor to produce higher power, a longer operating life and more economical, reactor structure materials which are capable of being operated at high temperatures are needed. The types of materials that are expected to meet these requirements include various types of ferritic / martensite steel, austenite, alloy steel containing nickel, and metal glass materials and ceramic materials. FeCr metal alloys are alloys that form the metals mentioned above, so it is important to conduct research both in simulation and experiment. Molecular Dynamics simulation of FeCr alloys using Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) has been done to explore their thermodynamic characteristics such as heat treatment, solubility of Cr, atomic radial distribution function (RDF). The results of the simulation are illustrated using Visual Molecular Dynamics (VMD) code.

THE SYNTHESIS OF PBZR0.52TI0.48O3 AND PBZR0.58TI0.42O3 CERAMIC POWDER BY USE MOLTEN SALT METHOD AND ITS INTERMEDIATE PRODUCT ANALYSIS Ahda, Syahfandi; Mardiyanto, Mardiyanto; Taufiq, Agus; Silalahi, Marzuki
Majalah Ilmiah Pengkajian Industri Vol 13, No 3 (2019): Majalah Ilmiah Pengkajian Industri
Publisher : BPPT

Lead zirconat titanate, Pb(Zr1-x,Tix)O3 is a material with high piezoelectric properties and many studies have been carried out in development, in order to improve the materials quality in various applications. Therefore,one of them is the development of synthesis with the molten salt method in this study. Choice of the molten salt method is simply and and not expensive. The salt ratio of NaCl / KCl at 1: 1 in moles as a solvent medium was carried out in synthesizing Pb(Zr1-x,Tix)O3. Likewise, the salt ratio with reactant/basic material was 1: 1 in weight percentages. An intermediate product is obtained if the dynamics of chemical reactions in the diffusion process occur indirectly or in stages. To identify intermediate products in this synthesis process, the sintering temperature has been varied to 575, 675 and 775 oC for samples A, B and C, respectively. The results of these syntheses have been identified and characterized using x-ray diffraction (XRD) methods. The Highscore program using the Rietveld method to identify the intermediate product content and each crystal structure has been applied in the rifenement process on the XRD intensity profile with a statistical error of less than 6%. Intermediate products have been obtained as follows, PbTiO3, PbZrO3 and Zr0.4Ti0.6O3. Whereas sample C has obtained two phases namely PbZr0.52Ti0.48O3 and PbZr0.58Ti0.42O3 with tetragonal (P4mm) and rhombohedral crystal structures (R3c).

METODE ARITMETIKA FORMULA BRAGG PADA PENGKAJIAN STRUKTUR KRISTAL BAJA SUPERALOI TIPE F1, A2 DAN A2-APS. Yunasz, Iing Farihin (Parikin); Dani, Mohammad; Sugeng, Bambang; Permatasari, Novita Dwi; Ahda, Syahfandi; Sukaryo, Sulistioso Giat
Majalah Ilmiah Pengkajian Industri Vol. 12 No. 3 (2018): Majalah Ilmiah Pengkajian Industri
Publisher : Deputi TIRBR-BPPT

Perekayasa material BATAN telah berhasil mensintesis serial baja superaloi tipe Austenitik (A2) dan tipe Feritik (F1). Beberapa bahan telah dilakukan treatments dengan memvariasi waktu penyinaran menggunakan arc plasma sintering (APS). Dalam studi ini dilakukan pengukuran difraksi sinar-X untuk menginvestigasi bentuk bangun struktur kristal dan parameter kisi dari baja feritik F1, baja austenitik A2 dan baja austenitik A2 yang disintering APS selama 2 detik penyinaran. Perhitungan dilakukan menggunakan formula Bragg denganÃ‚Â membandingkan deret aritmetika (hitung) S2 dan jarak interplanar dhkl. Diketahui bahwa:Ã‚Â baja feritik F1 berstruktur body centered cubic (BCC) dengan parameter kisi a = 2,87 Ãƒâ€¦. Baja austenitik A2 berstruktur Ã‚Â face centered cubic (FCC) dengan parameter kisi a = 3,59 Ãƒâ€¦. Baja austenitik A2 yang disintering APS selama 2 detik berstruktur Ã‚Â face centered cubic (FCC) dengan parameter kisi a = 3,60 Ãƒâ€¦. Pengamatan struktur mikro permukaan bahan menggunakan Mikroskop Optik (OM) dan Mikroskop Elektron (SEM) memperlihatkan mikrografi yang menarik. Mengasumsikan kondisi proses peleburan (casting) sama, kedua tipe bahan uji memiliki struktur cor yang mirip. Baja feritik F1 menampakkan batas butir (grain boundary) yang lebih halus jika dibandingkan dengan batas butir dalam baja austenitik A2 yang cenderung terlihat lebar garis batasnya. Sedang baja austenitik A2 yang disintering APS selama 2 detik, menampakkan pola butiran yang semula memanjang berubah struktur butiran (grain)-nya menjadi agak bulat-bulat (globular). Uji SEM memetakan sebaran presipitat pada baja feritik F1 di batas butir dan di dalam butir, sedangkan pada baja autenitik A2 tersebar di batas butir saja. Spektrum EDX menunjukkan komposisi presipitat pada baja feritik F1 meliputi C, Cr, dan Fe. Sedangkan pada baja austenitik A2: C, Cr, Fe, dan Ni. Dimungkinkan, krom karbida (Cr23C6) terbentuk sebagai precipitat di batas butir, karena bahan didominanasi konten unsur Cr dan C.Kata Kunci : feritik F1, austenitik A2, XRD, aritmetika, formula Bragg, struktur mikro.

MICROSTRUCTURE AND OXIDATION BEHAVIOR OF THE OXIDE DISPERSION STRENGTHENED STAINLESS STEEL 316L WITH ZIRCONIA DISPERSION Ahda, Syahfandi; Agus Sujatno; Diene Hairani; Nanda Shabrina; Sulistioso Giat; Bandriyana
Majalah Ilmiah Pengkajian Industri Vol. 15 No. 2 (2021): Majalah Ilmiah Pengkajian Industri
Publisher : Deputi TIRBR-BPPT

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Synthesis of the oxide dispersion sODS steels was performed by dispersing 0.5 wt % zirconia to the stainless steel SS 316L by the powder metallurgy method. The ball milling process was carried out for pre-alloying the elements continued with the consolidation performed by the compaction and sintering process using the APS (Arc Plasma Sintering). Analysis of microstructure was performed by observing the morphology, identify the phase and evaluate the oxide distribution. An oxidation test was carried out at 700oC for 8 hours using the MSB (Magnetic Suspension Balanced) apparatus to evaluate the primary oxidation curve. The same grain fineness consists of 2 dominant phases, so the presence of an austenitic phase and a ferritic phase has been analyzed from the X-Ray Diffraction pattern. The homogeneous distribution of zirconia was observed, followed by improvements in mechanical properties, which could be identified by hardness testing. The parabolic phenomenon oxidation curve was explained by the excellent high-temperature oxidation behaviour of the ODS steel, followed by the formation ofÂ ZrO2 oxide protective thin layer.

Analysis on the Crystal Structure of the Piezoelectric Nanocrystal Ceramic of Pr-doped Bi1/2Na1/2TiO3 using Molten-Salt Synthesis Ahda, Syahfandi; Ambarwati, Vita; Mardiyanto, Mardiyanto; Sukirman, Engkir; Sugeng, Bambang
Makara Journal of Science Vol. 25, No. 3
Publisher : UI Scholars Hub

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One of the future technologies in nuclear reactors is the ability of piezoelectric materials to monitor reactor cores as sensors. Particularly, Pb-free piezoelectric materials, such as Bi1/2Na1/2TiO3, have been examined to improve the ability of their piezoelectric properties. In this study, we attempted to add Pr6O11 dopant material with mole ratios of 0, 0.3, 0.5, and 0.7 mol%. The synthesis process used in this study is the molten-salt synthesis method with a NaCl and KCl salt mole ratio of 1:1. The crystal structure analysis using the refinement process of the Rietveld method of the HighScore software was performed. Accordingly, a rhombohedral crystal structure system with lattice parameters of 3.8809(2), 3.8831(2), 3.8834(7), and 3.8816(2) angstroms and variations in the content of Pr6O11 was obtained. The optimal lattice parameter was discovered with the addition of 0.5 mol% of Pr6O11. The morphology of the synthesis product is still unclear for each addition of dopant material due to the large number of granular agglomerations.

A New Synthesized Microalloys Steel ODS of High Amplitude Ultrasonically Irradiation Silalahi, Marzuki; Wicaksana, Hanif Abdurrahman; Aziz, Ferhat; Ahda, Syahfandi; Iskandar, Mohamad Riza
Makara Journal of Technology Vol. 23, No. 3
Publisher : UI Scholars Hub

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Micropowders of oxide-dispersion-strengthened (ODS) steel have been synthesized using the ultrasonic irradiation method with variations in amplitude. The ultrasonic irradiation process is performed for 50 h at a frequency of 20 kHz with 40%, 50%, and 60% amplitudes in toluene solution. The formation of Fe-Cr microalloys in the preparation of Fe- 15Cr-0.5Y2O3 powder was analyzed using SEM-EDS, X-ray diffraction (XRD), and TEM-EDS. The percentage of Fe- Cr phase mass fraction of ODS steel micropowder formed during ultrasonic irradiation with 40%:50%:60% amplitude was 12.2%:34.1%:22.1%, with 25.67:77.02:38.51 nm crystallite size. The crystallite size at 50% amplitude was the largest, and the diffusion process of Fe-Cr-Y2O3 microparticles was most dominant at 50% amplitude. The Fe and Cr phases are still present when the ODS particles successfully dispersed in the main particle.

Neutron Diffraction Study of Multiferroic 0.6NiFe2O4/0.4BaTiO3 Composite Sukirman, Engkir; Sarwanto, Yosef; Ahda, Syahfandi; Insani, Andon
Makara Journal of Technology Vol. 23, No. 3
Publisher : UI Scholars Hub

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Neutron diffraction study on the 0.6NiFe2O4/0.4BaTiO3 multiferroic composite has been carried out. The 0.6NiFe2O4/0.4BaTiO3 multiferroic composites have been synthesized by solid reaction method. In this study, 20 g of BaTiO3 (BTO) and 20 g of NiFe2O4 (NFO) compounds were prepared from the powder raw materials of BaO3 and TiO2 for BTO, and NiO and Fe2O3 for NFO. Furthermore, both BTO and NFO were each crushed for 5 hours using High Energy Milling (HEM). Then the BTO and NFO were calcined in the furnace at 950 °C/5 hours and 900 °C/5 hours, respectively. Both NFO and BTO precursors were manually mixed with a weight percent ratio of NFO:BTO was 100:0, 60:40, and 0:100, hereinafter referred to NFO, NFO/BTO, and BTO, respectively. Then the three samples were pressed into pellets. The pellets were then sintered at 1150 °C/5 hours with a heating rate of about 44.8 °C/min. Once cooled to room temperature within the furnace it was obtained NFO, BTO, and NFO/BTO multiferroic composite. The magnetic properties of the material were observed with the aid of the Vibrating Sample Magnetometer (VSM) instrument. The nuclear structure of BTO, and the magnetic structure of NFO, and NFO/BTO multiferroic composite were determined by neutron diffraction technique using the high resolution powder neutron diffractometer. The cations arrangement of NFO was obtained by whole pattern fitting with the Rietveld method based on neutron diffraction data using FullProf software. The cations arrangement was obtained by refining the occupancy of individual cation at tetrahedral and octa-hedral sites. The results of the analysis show that both NFO and 0.6NFO/0.4BTO samples have a mixed spinel structure, it means that there are cations of Ni2+ and Fe3+ on A-site and B-site. In NFO sample, the cations distribution among the A-site and B-site of NiFe2O4 is [Ni0.002Fe0.852][Ni0.006Fe0.862]2O4. The cations distribution among the A-site and B-site of NiFe2O4 in 0.6NFO/0.4BTO samples is [Ni0.0250Fe0.8975] [Ni0.012Fe0.950]2O4. So, the effect of adding BTO as a composite is to increase Ni2+ occupancy by 12.5 times on A-site and 2 times on B-site. The magnetic moment of mul-tiferroic 0.6NFO/0.4BTO composite is 2.4(5) μB same as one of NFO. The BTO content in the composite has caused ten-sile strains induced into the NFO lattice, and at the same time, tensile strains of NFO caused the compressive strain on the c lattice of BTO even though the unit cell volume of BTO is also increasing from 64.100(5) to 64.374(6) Å3.

Studi Awal Proses Pemolingan dan Karakterisasi Sifat Listrik Bahan Piezoelektrik Ramah Lingkungan (0,95-x) Bi0,5Na0,5TiO3 - 0,05Ba0,5TiO3 - xBi0,5K0,5TiO3 (BNT-BT-BKT) Iby, Arsal Chayri; Mahyudin, Alimin; Ahda, Syahfandi
Jurnal Fisika Unand Vol 2 No 1: Januari 2013
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.2.1.%p.2013

Telah dilakukan studi awal proses pemolingan dan karakterisasi sifat listrik terhadap bahan piezoelektrik ramah lingkungan BNT-BT-BKT. Dalam penelitian ini, sintesis bahan dilakukan dengan metode solid state reaction. Hasil analisis menunjukan bahwa Bahan BNT-BT-BKT memiliki struktur kristal perovskite rhombohedral yang bersifat hard ceramic. Bahan piezoelektrik 0,90BNT-0,05BT-0,05BKT memiliki konstanta dielektrik 1,29 x 102 dan temperatur Curie 428o C. Bahan piezoelektrik 0,93BNT-0,05BT-0,02BKT memilki konstanta dielektrik 1,87 x 102 dan temperatur Curie 428o C. Dari hasil poling 0,90BNT-0,05BT-0,05BKT didapatkan nilai frekuensi diri dan terlihat tegangan yang dihasilkan ketika dilakukan uji tekan terhadap bahan.

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