Garuda - Garba Rujukan Digital

p-Index From 2021 - 2026

1.829

P-Index

This Author published in this journals

All Journal Jurnal Sains Materi Indonesia Metalurgi International Journal of Recent Technology and Applied Science (IJORTAS) Journal of Materials Exploration and Findings Makara Journal of Technology Metalurgi

Akhmad Herman Yuwono

Departemen Metalurgi Dan Material Fakultas Teknik Universitas Indonesia

Author-ID : 426772

Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

Published : 20 Documents Claim Missing Document

Claim Missing Document

Articles

Title

STUDI PERBANDINGAN EFEK FOTOKATALISIS Fe2O3-TiO2 HASIL EKSTRAKSI ILMENIT BANGKA DAN P-25 DEGUSSA UNTUK APLIKASI PENGOLAHAN LIMBAH CAIR TPA CILOWONG[The Photocatalytic Effect of P-25 Degussa and Fe2O3-TiO2 Derived from Bangka- Indonesia Ilmenite Extraction for Waste Water Treatment of Leachate on the Landfill Cilowong] Latifa Hanum Lalasari; Akhmad Herman Yuwono; Firdiyono Firdiyono; Lia Andriyah; Elfi N; Sri Harjanto; Bambang Suharno
Metalurgi Vol 27, No 3 (2012): Metalurgi Vol.27 No.3 Desember 2012
Publisher : National Research and Innovation Agency (BRIN)

FABRIKASI NANOTUBES TiO2 DENGAN TINGKAT NANOKRISTALINITAS TINGGI MELALUI PERLAKUAN KOMBINASI ANIL DAN PASCA-HIDROTERMAL UNTUK APLIKASI SEL SURYA TERSENSITISASI ZAT PEWARNA[Fabrication of Highly Nanocrystalline TiO2 Nanotubes Through a Combination of Pre-Annealing and Hydrothermal Treatment for Dye Sensitized Solar Cell Application] Alfian Ferdiansyah; Akhmad Herman Yuwono; Norifon Sofyan; Indriana Kartini; Togo Hadi Pujianto; Badrul Munir
Metalurgi Vol 27, No 2 (2012): Metalurgi Vol. 27 No. 2 Agustus 2012
Publisher : National Research and Innovation Agency (BRIN)

Pengaruh Waktu Deposisi dan Temperatur Substrat Terhadap Pembuatan Kaca Konduktif FTO (Fluorine doped Tin Oxide) [The Influence of Deposition Time and Substrate Temperature in Manufacturing Process of FTO (Fluorine doped Tin Oxide) Conductive Glass] Tri Arini; Latifa Hanum Lalasari; Akhmad Herman Yuwono; F Firdiyono; Lia Andriyah; Achmad Subhan
Metalurgi Vol 32, No 1 (2017): Metalurgi Vol. 32 No. 1 April 2017
Publisher : National Research and Innovation Agency (BRIN)

Manufacturing FTO (fluorine-doped tin oxide) is expected to replace ITO (indium tin oxide) because the process is simple and relatively low cost. Tin chloride precursor with fluorine doping is prepared via sol-gel method with a coating process with spray pyrolisis technique can be considered as a new breakthrough in DSSC device structures. This experiment uses the raw material tin (II) chloride hydrate (SnCl2.2H2O) as precursors and ammonium fluoride (NH4F) as a doping ratio of 6% wt with variation in temperatures of 250, 300, 350, 400 °C and time resistivities of 5, 20, 30 and 40 minutes. The results showed that the longer deposition time decreasing value of conductive glass resistivity. This condition would reduce the value of transmittance. High transmittance and low resistivity obtained on the variation of deposition time 5 minutes with a substrate temperature of 300 °C with a resistivity value of 3.16 x 10-4 Ω.cm and transmittance value of 86.74%AbstrakPembuatan FTO (flourine-doped tin oxide) ini diharapkan dapat menggantikan fungsi ITO (indium tin oxide) karena proses pembuatan yang sederhana dan biaya yang relatif rendah. Prekursor timah klorida dengan doping flourine yang dipreparasi melalui metode sol-gel dengan proses pelapisan dengan teknik spray pyrolisis dapat dipertimbangkan sebagai suatu terobosan baru di dalam struktur device sel surya tersensitasi zat pewarna. Percobaan ini menggunakan bahan baku timah (II) klorida hidrat (SnCl2.2H2O) sebagai prekursor dan amonium florida (NH4F) sebagai doping dengan rasio 6 %berat dengan variasi temperatur 250, 300, 350, 400 °C dan dengan variasi waktu 5, 20, 30, dan 40 menit. Hasil percobaan menunjukkan bahwa semakin lama waktu deposisi maka akan semakin kecil nilai resistivitas kaca konduktif. Namun semakin lama waktu deposisi akan mengurangi nilai transmitansi. Pada percobaan ini menghasilkan transmitansi tinggi dan resistivitas rendah diperoleh pada variasi waktu deposisi 5 menit dengan temperatur substrat 300 °C dengan nilai resitivitas 3,16 x 10-4 Ω.cm dan nilai transmitansi 86,74%.

FABRIKASI NANOROD SENG OKSIDA (ZnO) MENGGUNAKAN METODE SOL-GEL DENGAN VARIASI KONSENTRASI POLYETHYLENE GLYCOL DAN WAKTU TUNDA EVAPORASI AMONIA Akhmad Herman Yuwono
Metalurgi Vol 26, No 2 (2011): Metalurgi Vol.26 No.2 Agustus 2011
Publisher : National Research and Innovation Agency (BRIN)

Seng oksida (ZnO) adalah salah satu material semikonduktor yang banyak digunakan dalam aplikasi katalitik, elektronik dan optoelektronik. Pada penelitian ini, ZnO nanorods telah berhasil disintesis menggunakan metode sol-gel dengan campuran (Zn(NO3 ) 2 .4H2 O), NH4 OH, dan polyethylene glycol (PEG). Variasi pada konsentrasi PEG dan penahanan laju evaporasi amoniak pada larutan telah dilakukan dan nanorod ZnO yang dihasilkan dikarakterisasi dengan XRD dan SEM untuk menginvestigasi perbedaan diameter, morfologi dan tingkat nanokristalinitas nanorod ZnO. Penambahan PEG dari 1 hingga 3 gram pada larutan meningkatkan ukuran diameter rata-rata nanorods dari 157 menjadi 464 nm. Namun demikian tidak didapatkan adanya peningkatan ukuran nanokristalit ZnO di dalam struktur solid nanorod tersebut. Pada variasi waktu tunda evaporasi amonia selama 1 dan 2 jam, terjadi penurunan diameter nanorod menjadi 410 dan 328 nm, sebagai perbandingan terhadap diameter nanorod ZnO tanpa proses penundaan evaporasi ammonia yang mencapai 464 nm. Sebaliknya, besar kristalit di dalam struktur nanorod ZnO bertambah dari 121,49 menjadi 166,59 nm sejalan dengan penambahan waktu tunda evaporasi ammonia dari 1 hingga 2 jam, sebagai perbandingan terhadap ukuran kristalit nanorod ZnO tanpa proses penundaan evaporasi ammonia yang hanya mencapai 94,77 nm. AbstractZinc oxide (ZnO) is one of semiconductor materials which has been widely used for catalytic, electronic and optoelectronic applications. In the present research, ZnO nanorod has been successfully synthesized through a sol-gel method using (Zn(NO3)2.4H2O), NH4Keywords: ZnO nanorods, PEG concentration, Evaporation delay time, Crystallinity OH, and polyethylene glycol (PEG) precusrors. Variation in PEG concentration and ammonia evaporation delay time were performed and the resulting ZnO nanorods were characterized by XRD and SEM to investigate the difference in diameter, morphology and nanocrystallinity. It was revellead that the addition of PEG concentration from 1 to 3 grams has increased the average diameter of ZnO nanorods from 157 to 464 nm. However, there was no an increase in the crystallite size on those nanorod solid structures. The ammonia evaporation delay time from 1 to 2 hours has resulted in a deacrease in the average diameter of ZnO nanorods from 410 to 328 nm, in comparison to those of without evaporation delay time which can reach up to 464 nm. By contrast, the average crystallite size of ZnO phase in the nanorod structures has increased from 121.49 to 166.59 nm when the evaporation delay time was prolonged from 1 to 2 hours, as compared to those of without evaporation delay time which can only reach 94.77 nm in size.

Residual Stress Measurement of Used Mining Dump Truck Frame for Remanufacturing Purposes Ferdiyanto, David; Sofyan, Nofrijon; Yuwono, Akhmad Herman; Dhaneswara, Donanta
Metalurgi Vol 38, No 3 (2023): Metalurgi Vol. 38 No. 3 2023
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/metalurgi.2023.730

Remanufacturing the main frame of a mining dump truck can save cost, energy, and materials in heavy equipment industries. It also can reduce CO2 emissions for environmental preservation to achieve sustainability. However, since the mainframe received a dynamic load during operation, it presumably leaves accumulated residual stresses in the frame. The residual stress, particularly tensile residual stress, stands out as a primary contributing factor to the initiation of cracks, which may ultimately result in failures. In this paper, the residual stress of the used mining dump truck main frame was identified by modeling simulation using FEA (finite element analysis) and actual measurement using a portable x-ray residual stress analyzer with the cos α method. The results showed that the weld area subjected to dynamic loads exhibited the highest tensile residual stress, reaching approximately +772 MPa. This specific region emerges as a critical area demanding attention during the remanufacturing process. The application of PWHT (post-weld heat treatment) at 400 °C for 1 hour effectively reduced residual stress on the weld joint, predominantly tensile residual stress, by more than 80%.

MORPHOLOGY AND RESISTIVITY VALUE OF FLOURINE-DOPED TIN OXIDE (FTO) USING INDONESIAN LOCAL DIMETHYLTIN DICHLORIIDE (DTMC) PRECURSORS Rizki, Apti Mira; Yunita, Fariza Eka; Lalasari, Latifa Hanum; Irawan, Januar; Arini, Tri; Firdiyono, Florentinus; Andriyah, Lia; Natasha, Nadia Chrisayu; Yuwono, Akhmad Herman
Metalurgi Vol 37, No 3 (2022): Metalurgi Vol. 37 No. 3 Desember 2022
Publisher : National Research and Innovation Agency (BRIN)

Transparent Conductive Oxide (TCO) is the main component for solar cell fabrication. One of the promising types of TCO is fluorine-doped tin oxide (FTO). The method used in depositing the conductive layer of FTO is spray pyrolysis with an ultrasonic nebulizer. The precursor is a local Indonesian product, dimethyl tin dichloride (DMTC), with doping ammonium fluoride (NH4F). The variable that used in this study were variations in deposition time (5. 10. 15. 20, and 25 minutes) with a fixed substrate temperature at 300°C and doping variations (un-doped, 2 wt.% doped and 8 wt.% doped) to see the effect of adding F doping to the precursor solution. The resistivity value with deposition time of 5. 10. 15. 20 and 25 minute (2 wt.% doped) is 0.218x100; 0.449x10-1; 1,567x10-2; 0.676x10-2 0.377x10-2 Ω.cm. For doping variations (un-doped, 2 wt% doped and 8 wt% doped) the value is 0.883x10-2; 0.377x10-2; 0.506x10-3 Ω.cm. There is a decreasing trend in the resistivity values obtained along with the increase in deposition time and the addition of doping to obtain better conductive properties. The grain size will increase with increasing deposition time and the addition of doping. The optimum resistivity value obtained in this study was 0.377x10-2 Ω.cm, obtained at the deposition time of 25 minutes with 2 wt.% doping.

Effect of Heating Temperature and Die Insert Draft Angle on the Flowability of Hot Forged SCM435 Steel Sofyan, Nofrijon; Heruwiyono, Maulana; Yuwono, Akhmad Herman; Dhaneswara, Donanta
Metalurgi Vol 37, No 2 (2022): Metalurgi Vol. 37 No. 2 Agustus 2022
Publisher : National Research and Innovation Agency (BRIN)

The problem of flowability in a closed forging process for heavy equipment industry is still widely found and this may affect the quality of the resulting product. To obtain the solution for this problem, in this work, the effect of heating temperature and die insert draft angle on the characteristic of hot forged SCM435 steel used for undercarriage track roller has been examined. The workpieces were heated at temperature variations of 1150 °C, 1200 °C, 1250 °C and were hot forged at die insert draft angles of 3°, 5°, and 7° to form undercarriage track roller products. The mechanical properties of the products were characterized through hardness and dimension examination, whereas the microstructure was characterized using an optical microscope. The results showed that increasing the heating temperature and die insert draft angle resulted in good flowability. The best result was obtained from the heating temperature of 1250 °C at the die insert draft angle of 7°, with diameter and height of 191.2 mm and 53.6 mm, respectively. This characteristic of the obtained hot-forged product agreed with that of the specified forging design for the undercarriage track roller

Synthesis of Tin Oxide Nanocrystallites with Various Calcination Temperatures Using Co-Precipitation Method with Local Tin Chloride Precursor Panthoko, Norbert Egan Christo; Septiningrum, Fairuz; Yuwono, Akhmad Herman; Nurhidayah, Eka; Maulana, Fakhri Akbar; Sofyan, Nofrijon; Dhaneswara, Donanta; Lalasari, Latifa Hanum; Arini, Tri; Andriyah, Lia; Firdiyono, Florentinus; Ardianto, Yahya Winda; Pawan, Ria Wardhani
Metalurgi Vol 38, No 1 (2023): Metalurgi Vol. 38 No. 1 2023
Publisher : National Research and Innovation Agency (BRIN)

Indonesia is one of the largest tin metal producers in the world, and one of its derivative products is tin chloride (SnCl4). This material has been used as a raw ingredient for the production of organotin compounds such as methyltin mercaptide for PVC (polyvinyl chloride) plastic industry as a heat stabilizer. On the other hand, this precursor can be used to synthesize SnO2 nanomaterials, which have other strategic potentials, including photocatalysts and solar cell applications. In this study, the synthesis of SnO2 nanocrystallites was carried out using a local tin chloride precursor via the co-precipitation method, followed by a calcination process at temperatures of 300, 400, 500, and 600 °C, for further usage as an ETL (electron transport layer) in a PSC (perovskite solar cell) device. The basic properties characterization was carried out using XRD (X-ray diffraction), ultraviolet-visible (UV-Vis) spectroscopy, and SEM (scanning electron microscopy), while the photocurrent-voltage (I-V) curve photovoltaic performance of the device was performed using a semiconductor parameter analyzer. The characterization results showed that increasing the calcination temperature from 300 to 600 °C increased the average crystallite size from 1.19 to 13.75 nm and decreased the band gap energy from 3.57 to 3.10 eV. The highest PCE (power conversion efficiency) was obtained from the device fabricated with SnO2 nanocrystallites calcined at a temperature of 300 °C, which was 0.0024%. This result was obtained due to the highest transmittance of this sample as compared to others; the higher the transmittance, the better the performance of the ETL, which in turn increased the overall efficiency of the PSC

Study of Iron and Calcium Removal on Manganese Sulfate Precursors for Battery Cathode Raw Material Applications Hakim, Agsel Fauzia; Andriyah, Lia; Oediyani, Soesaptri; Lalasari, Latifa Hanum; Sulistiyono, Eko; Irawan, Januar; Arini, Tri; Yunita, Fariza Eka; Suharyanto, Ariyo; Setiawan, Iwan; Firdiyono, Florentinus; Yuwono, Akhmad Herman
Metalurgi Vol 39, No 2 (2024): Metalurgi Vol. 39 No. 2 2024
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/metalurgi.2024.753

Global battery sales are expected to reach $310.8 billion in 2027, up 14.1% from 2020. 95% of the world's batteries are lead-acid, lithium-ion, or nickel-based. One of the most popular batteries on the global market is lithium-ion, which uses MnSO4 powder as its cathode raw material. Manganese sulfate-based lithium-ion batteries can be made using Indonesian resources, specifically manganese ore from Trenggalek. Trenggalek manganese ore is of poor quality and contains impurities, primarily Fe and Ca. To produce 98% powder manganese sulfate, the solution is prepared, reduced with briquette charcoal, leached, precipitated, carbonated, and crystallised. NH4OH reagent is used to remove Fe through precipitation, and the carbonatation process is employed to eliminate Ca, resulting in 97.237% purity of manganese sulfate powder product. This outcome is achieved under precipitation process conditions of [NH4OH 2M], T = 80 °C, pH = 4, t =180 minutes, while carbonatation process conditions are T=50 °C, t = 120 minutes.

Co-Authors Achmad Subhan Achmad Subhan Alfian Ferdiansyah Alfian Ferdiansyah Alfian Ferdiansyah Amalia Sholehah, Amalia Andika, Geo Surya Andriyah, Lia Andriyah, Lia Anne Zulfia Ardianto, Yahya Winda Arif Rahman Arif Rahman Asral, D. Rizal Badrul Munir Badrul Munir, Badrul Bambang Priyono Bambang Suharno Burhanuddin, Fakhri Daniel Kurniawan Dhaneswara, Donanta Eka Putri, Sonia Eko Adhi Setiawan Eko Sulistiyono, Eko Elfi N Eny Kusrini Evvy Kartini F Firdiyono Ferdiyanto, David Firdiyono Firdiyono firdiyono, F Firdiyono, Firdiyono Florentinus Firdiyono Ghiska Ramahdita, Ghiska Hakim, Agsel Fauzia Heri Jodi, Heri Heruwiyono, Maulana Indriana Kartini Indriana Kartini Irawan, Januar Iwan Setiawan johansyah johansyah John Wang Lalasari, Latifa Hanum Lalasari, Latifa Hanum Latifa Hanum Lalasari Latifa Hanum Lalasari Lia Andriyah Lia Andriyah Mario Marfelly, Mario Maulana, Fakhri Akbar N, Elfi Natasha, Nadia Chrisayu Nofrijon Sofyan, Nofrijon Norifon Sofyan Nurhidayah, Eka Panthoko, Norbert Egan Christo Pawan, Ria Wardhani Pujianto, Togo Hadi Rizki, Apti Mira Septiningrum, Fairuz Soesaptri Oediyani Sofyan, Norifon Sri Harjanto Sri Harjanto Suharyanto, Ariyo Togo Hadi Pujianto Tri Arini Tri Arini, Tri Wahid Muhamad Furkon Rahmatulloh, Wahid Muhamad Furkon Wulandari Handini Wulandari Handini Yu Zhang Yuliati, Dona Yunita, Fariza Eka

Title Search

Found 9 Documents Search Journal : Metalurgi

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title

Found 9 Documents
Search
Journal : Metalurgi