RATIH LANGENATI
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PELAPISAN BAJA TIPE ST-37 DENGAN NANO POWDER PACK BORON KARBIDA Sugondo .; Ratih Langenati; Widjaksana .; Basuki Agung Pudjanto
Jurnal Teknologi Bahan Nuklir Vol 2, No 2 (2006): Juni 2006
Publisher : PTBN - BATAN

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Abstract

ABSTRAK PELAPISAN BAJA TIPE ST-37 DENGAN NANO POWDER PACK BORON KARBIDA. Baja ST-37 banyak digunakan dalam industri. Kualitas baja ST-37 dapat ditingkatkan melalui pelapisan permukaan. Perkembangan teknologi dewasa ini menunjukkan kecenderungan yang mengarah pada sains nano dan teknologi nano yang dapat diaplikasikan dalam berbagai bidang antara lain energi, industri, kesehatan, informatika dan komunikasi maupun pangan yang dibutuhkan masyarakat luas dengan nilai jual yang kompetitif. Langkah-langkah boronisasi powder pack meliputi: perlakuan awal, persiapan serbuk, persiapan boronizing agent, persiapan kontainer, proses boronisasi, metalografi, uji kekerasan, dan uji korosi. Dari percobaan diperoleh hasil sebagai berikut. Mekanisme proses boronisasi ada tiga tahap, yaitu tahap pembentukan senyawa borida, tahap difusi, dan tahap pertumbuhan serta orientasi butir. Karbon pada B4C pada proses boronisasi tidak berdifusi masuk ke dalam substrat. Pembentukan senyawa borida mulai terjadi pada temperatur 600 °C, proses difusi mulai terjadi pada temperatur 700 °C, dan proses pertumbuhan serta orientasi kristal mulai terjadi pada temperatur 800 °C. Kekerasan lapisan boron yang diperoleh mencapai 1115 VHN. Lapisan hasil proses boronisasi tahan terhadap korosi HCl 10%. KATA KUNCI: Baja tipe ST-37, Nano powder pack, Boron karbida ABSTRACT COATING ON STEEL ST-37 TYPE WITH NANO POWDER PACK OF BORON CARBIDE. Steel ST-37 is a material widely used in industry. The quality of steel ST-37 can be improved by means of surface coating. At present the development of the technology shows the tendency toward nanoscience and nanotechnology that can be applied to various fields, among others energy, industry, medicine, information technology and communication as well as food necessitated by people at competitive selling prices. The steps in powder pack boronizing include: Pre-treatment, powder preparation, boronizing agent preparation, container preparation, boronizing process, metallography, hardness testing and corrosion testing. From the study, it is concluded as follows. The mechanism of boronizing process is divided into three stages, which are the boride compound formation stage, the diffusion stage, and the grain growth and orientation stage. Carbon in B4C on boronizing process does not diffuse into the substrate. The formation of boride compound begins to occur at a temperatur of 600 °C, the diffusion process at 700 °C, and the grain growth and orientation at 800 °C. The hardness of boron coating reaches a value of 1115 VHN. Coating by boronizing process shows corrosion resistance in 10% HCl. FREE TERMS: ST-37 type steel, Nano powder pack, Boron carbide
PURIFICATION OF INDONESIAN NATURAL GRAPHITE AS CANDIDATE FOR NUCLEAR FUEL MATRIX BY ACID LEACHING METHOD: CHEMICAL CHARACTERIZATION Deni Mustika; Torowati Torowati; Arbi Dimyati; Sudirman Sudirman; Adel Fisli; I Made Joni; Ratih Langenati
Urania : Jurnal Ilmiah Daur Bahan Bakar Nuklir Vol 26, No 3 (2020): Oktober, 2020
Publisher : website

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/urania.2020.26.3.6059

Abstract

PURIFICATION OF INDONESIAN NATURAL GRAPHITE AS CANDIDATE FOR NUCLEAR FUEL MATRIX BY ACID LEACHING METHOD: CHEMICAL CHARACTERIZATION. Graphite matrix in Pebble Bed Reactor (PBR) – High Temperature Gas Cooled Reactor (HTGR) has an important role as heat transfer medium, neutron moderator and structural material to protect fuel. Thus, graphite matrix must fulfill chemical and physical characteristics for PBR-HTGR fuel. Indonesia has graphite sources in several regions that can potentially be purified. This research aimed to purify Indonesian natural graphite by several variation of acids and to perform chemical characterizations. Natural graphite from flotation process was purified by several variations of acid, i. e., hydrofluoric acid (HF), sulphuric acid + nitric acid (H2SO4 + HNO3) and hydrofluoric acid + hydrochloric acid + sulphuric acid (HF + HCl + H2SO4) and subsequently followed by chemical characterizations such as purity level, ash content, and boron quivalent. The highest purity was obtained in the purification process by HF with carbon content up to 99.52%; this purity level fulfills the specification of nuclear graphite (>99%). Ash content analysis shows a value in compliance with the specification requirement, i.e., < 100 ppm, and boron equivalent value also fulfills the specification value of < 1 ppm. It can be concluded from this study that the graphite purified by acid leaching with HF can be used as fuel matrix candidate but is qualified as low quality. Futher research is required to produce high quality nuclear graphite, particularly research in the minimization of the impurity by evaporation at temperatures over 950 oC to by far lower the ash content.Keywords:  Indonesian natural graphite, purification, nuclear fuel matrix, acid leaching, chemical characterization.