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Transmission Electron Microscopy Characterization of High-Temperatur Oxidation of Fe-20Cr-5Al Alloy Prepared by Focused Ion Beam Technique Dani, Mohammad; Untoro, Pudji; Panca Putra, Teguh Yulius Surya; Parikin, Parikin; Mayer, Joachim; Dimyati, Arbi
Makara Journal of Technology Vol 19, No 2 (2015)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (397.594 KB) | DOI: 10.7454/mst.v19i2.3141

Abstract

The Focused Ion Beam (FIB) technique was applied for cross section preparation of the oxidized alloy for Transmission Electron Microscopy (TEM) study. Prior to preparation, the specimens of Fe-20Cr-5Al alloy sheet were oxidized in air at 1200 oC for 2 minutes, 10 minutes, 2 hours, and 100 hours. The microstructure and elemental composition of the samples were characterized using TEM equipped with an Energy Dispersive X-Ray Spectroscopy (EDX). The Electron Energy Loss Spectroscopy (EELS) was used to determine of the light elements. The TEM investigation reveals remarkable microstructure evolution of the specimens during oxidation which generally exhibit a typical multi-layer structure. The TEM images, however, can provide detailed description about the phases occur after oxidation such as the Tungsten (W) and the Gallium (Ga) layers on top of the samples obviously formed during FIB preparation, the formation of Al2O3 and Cr2O3 layer, MgAl2O4 spinel, porosity, Zr/Hf/Mg phases or clusters inside the oxide scale. Hence, the FIB technique has been proven to be reliable preparation technique for microstructural and elemental studies of Fe-20Cr-5Al alloy using TEM.
MODIFIKASI PEMBENTUKAN LAPISAN Zn PADA PERMUKAAN BAJA DUAL FASA DENGAN NITRIDASI RINGAN Dimyati, Arbi
Widyariset Vol 12, No 1 (2009): Widyariset
Publisher : LIPI-Press

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Abstract

In this work an experimental series was performed in order to modify the surface properties and galvanise ability of the dual-phase steel by the nitriding in an ammonia containing atmosphere (bright nitriding) during re-crystallisation annealing. The samples were characterized using various electron microscopy techniques and special preparation methods. The investigations show that during re-crystallization annealing with a relatively short duration because the nitrides formation with a large amount of nitrogen atoms can incorporate into the surface near area of the steel. The steel microstructures and the oxidation behavior of the alloying elements on the steel surface are positively changed. The decreasing of oxidation causes the surface activation that increases the steel/zinc reactions during hot-dipping. The formation of the Fe7415 inhibition layer also changes. The best quality of the zinc layer surfaces are achieved on the samples after annealing with ammonia concentration between 0.25 and 1 vol.-%. Therewith a new alternative for controlling the hot-dip galvaniseability of highstrength steels are proposed.   
STUDI SCANNING ELECTRON MICROSCOPY (SEM) UNTUK KARAKTERISASI PROSES OXIDASI PADUAN ZIRKONIUM Sujatno, Agus; Salam, Rohmad; Bandriyana, Bandriyana; Dimyati, Arbi
Jurnal Forum Nuklir JFN Vol 9 No 1 Mei 2015
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (568.362 KB)

Abstract

STUDI SCANNING ELEKTRON MICROSCOPY (SEM) UNTUK KARAKTERISASI PROSES OXIDASI PADUAN ZIRKONIUM. Studi analisis Scanning Electron Microscopy (SEM) telah dilakukan untuk mengkarakterisasi struktur mikro dan lapisan oksida paduan zirkonium, bahan yang prospektif digunakan sebagai material kelongsong bahan bakar reaktor nuklir generasi ke IV dan struktur reaktor fusi modern. Tujuan penelitian adalah guna mendapatkan informasi yang detil dan akurat yang diperlukan untuk mendukung analisis ketahanan korosi paduan zirkonium yang disebabkan oleh proses oksidasi suhu tinggi dengan menggunakan berbagai metode analisis pada SEM. Sampel uji yang digunakan adalah ingot paduan zirkonium ZrNbMoGe setelah tes oksidasi dalam Mass Suspension Balance (MSB) pada temperatur 500 dan 700 oC masing-masing selama 5 jam. Komposisi unsur dalam sampel paduan adalah 96,9 %Zr, 2,5 %Nb, 0,5 %Mo dan 0,1 %Ge. Pengujian SEM dilakukan dengan JEOL JSM-6510LA yang dilengkapi dengan perangkat Energy Dispersive X-Ray Spectroscopy (EDS) untuk analisis komposisi kimia. Metode Secondary Electron (SE) dan Backscattered Electron (BSE) dengan opsi Low-Vacuum dilakukan untuk mendapatkan kontras yang optimal. Hasil analisa menunjukan bahwa pada kedua sampel telah tumbuh lapisan oksida berupa ZrO2 dengan ketebalan maksimal 2.4 dan 3.5 mm untuk masing-masing temperatur 500 dan 700 oC. Gambar BSE telah menunjukan batas lapisan dengan jelas, tidak memberikan ruang untuk interpretasi ganda.
Characteristics of Vulcanizate Rubber Using Composite Latex – Modified Cassava Starch as Filler Prasetya, Hari Adi; Marlina, Popy; Dimyati, Arbi
Indonesian Journal of Chemistry Vol 18, No 4 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (505.615 KB) | DOI: 10.22146/ijc.25713

Abstract

The research on Characteristic of vulcanizate rubber using cassava starch composite (Manihot glaziovii) modification - latex as filler has been done. The composite variation of cassava starch concentration is 0, 40, 80, 120, 160 and 200 phr in three replications. Microstructure and elemental samples in SEM EDX and FTIR Spectroscopy method analysis, while physical properties using the standard testing equipment. The results showed that the concentration of cassava has a significant influence that is hardness, tensile strength, elongation at break, tear resistance and ozone resistance. The best rubber hardness specification was composite with modified cassava starch concentrations of 120, 160 and 200 phr with value 57, 61 and 65 Shore A. The best tensile strength of cassava starch concentration 80 and 120 phr with value 160 and 167 kg/cm2, while the best result of the extension of cassava starch concentration elongation at break 80, 120, and 160 phr is 652, 741, and 748%, and tear resistance 80, 120, 160 and 200 phr with value 14.21, 15.96, 15.16 and 14.47. The ozone resistance for all concentrations meets the requirements of commercial vulcanizate rubber. The latex-modified cassava starch composite can be used as a filler for rubber products and as an alternative to commercial fillers.