Jurnal Metalurgi dan Material Indonesia https://materialmetalurgi.id/index.php/JMMI <p><strong>Jurnal Metalurgi dan Material Indonesia (JMMI)</strong> merupakan terbitan berkala makalah ilmiah mencakup keilmuan teknik metalurgi <em>(metallurgy)</em> dan teknik material (<em>materials science and engineering</em>). Topik-topik pilihan yang termasuk dalam lingkup JMMI antara lain adalah sebagai berikut.<br>&nbsp; &nbsp;1. Rekayasa struktur, sifat, dan degradasi material<br>&nbsp; &nbsp;2. Rekayasa proses metalurgi dan pemrosesan material<br>&nbsp; &nbsp;3. Pengembangan metode karakterisasi material<br>&nbsp; &nbsp;4. Pemodelan dan simulasi dalam rekayasa metalurgi dan material<br>&nbsp; &nbsp;5. Pendidikan keilmuan metalurgi dan material</p> en-US metalurgimaterial.id@gmail.com (Arif Basuki) metalurgimaterial.id@gmail.com (Untung Ari Wibowo, MT) Sat, 31 Aug 2019 00:00:00 +0700 OJS 3.1.2.1 http://blogs.law.harvard.edu/tech/rss 60 Karakterisasi Bilah Gamelan Berbahan Kuningan Cu22Zn Melalui Proses HPDC dan <i>Hot Forging</i> https://materialmetalurgi.id/index.php/JMMI/article/view/33 <p>Alat musik gamelan diproduksi menggunakan material logam non ferro kuningan dan perunggu melalui teknik tempa panas <em>manual forging</em>. Kelemahan teknik tempa dapat menurunkan sifat mekanis paduan akibat deformasi plastis serta energi untuk menempa yang besar. Kualitas bunyi juga semakin menurun pada kurun waktu akibat terbentuknya tegangan sisa. Material yang digunakan dalam penelitian ini Cu-22%Zn. Spesimen bilah gamelan dibuat melalui teknik <em>H</em><em>igh </em><em>P</em><em>ressure </em><em>D</em><em>ie </em><em>C</em><em>asting/HPDC </em>dengan tekanan kerja 200 MPa<em>.</em> dan &nbsp;teknik <em>hot forging</em> dari proses pengecoran <em>sand casting</em> dengan tingkat reduksi sebesar 5%. Mikrostruktur hasil teknik <em>HPDC</em> menunjukkan butir bulat kasar dan porositas, sedangkan pada teknik tempa panas menghasilkan mikrostruktur pipih memanjang dengan sedikit porositas. Teknik tempa panas menunjukkan kenaikan kekerasan sebesar 62,2% VHN lebih tinggi dibanding teknik cor <em>HPDC</em>. Densitas teknik tempa panas meningkat sebesar 7,9% dengan penurunan porositas sebesar 75,6%. Sound akustik teknik cor HPDC menunjukkan frekuansi alamiah sebesar 354 Hz dan teknik <em>hot forging</em> sebesar 672,7 Hz.</p> Sugeng - Slamet, Qomaruddin Qomaruddin Copyright (c) 2019 Sugeng Slamet, Qomaruddin Qomaruddin http://creativecommons.org/licenses/by-nc-nd/4.0 https://materialmetalurgi.id/index.php/JMMI/article/view/33 Sat, 31 Aug 2019 00:00:00 +0700 Pengaruh Penambahan <i>Hydroxyapatite</i> Terhadap Struktur Mikro dan Sifat Mekanik Paduan Mg-Al-Zn Melalui Proses <i>Thixoforming</i> https://materialmetalurgi.id/index.php/JMMI/article/view/25 <p><em>Magnesium alloys are lightweight metallic materials with low mechanical properties. Therefore, in an effort to meet the application requirements for orthopedic implants, the mechanical properties such hardness and tensile strength of Mg-Al-Zn shall be improved. The purpose of this research is to investigate the effect of adding hydroxyapatite (HA) particle to changes in microstructure, hardness and mechanical properties regarding with ultimate strength. HA is a potential compound to be a suitable candidate for applied to orthopedic implants. And thixoforming process is a potential process to be a grain refiner (globular) so as to improvethe mechanical properties magnesium alloy.in this research, the molten Mg-Al-Zn alloy is added HA with a various range of 1.5, 2, 2.5 wt% and then water quenched. Futhermore, Mg-Al-Zn-HA is heated at 530°C (semi-soid temperature) and then thixoforming process is performed. The </em><em>characterization result </em><em>as cast showed that increasing of </em><em>HA content made the smaller </em><em>dendritic structure. </em><em>And the result of thixoforming product showed the microstructure is globular grains with maximum hardness value of 86,33 VHN in 2.5% HA and the maximum ultimate tensile&nbsp; strength value of 328.63 MPa in 2% HA with hardness value of 83.42 VHN lower than 2.5% HA alloy. This is due to the presence of porosity in the 2.5% HA alloy with porosity area 4.66 mm<sup>2</sup>.</em></p> Andy Saputro, Intan Khoerunisa, Kusharjanto Suhirman, Supono Adi Dwiwanto Copyright (c) 2019 Andy Saputro, Intan Khoerunisa, Kusharjanto Suhirman, Supono Adi Dwiwanto http://creativecommons.org/licenses/by-nc-nd/4.0 https://materialmetalurgi.id/index.php/JMMI/article/view/25 Sat, 31 Aug 2019 00:00:00 +0700 <i>Repair Welding</i>: Pengaruh Pengelasan Perbaikan Berulang dengan Kombinasi Proses GTAW dan SMAW terhadap Struktur Mikro dan Sifat Mekanik Baja Tahan Karat Dua Fasa Austenitik-Feritik (<i>Duplex</i>) UNS S31803 https://materialmetalurgi.id/index.php/JMMI/article/view/32 <p><em>During welding and also in the stages of fabrication and assembly, welding repair sometimes required to eliminate the welding defects present. This paper focuses on the effect of multiple repair welding on microstructure and mechanical properties of Duplex Stainless Steel UNS S31803. Three times welding repair were performed using combination of Gas Tungsten Arc Welding (GTAW) for root pass up to hot passes and Shielded Metal Arc Welding (SMAW) processes for fill passes up to finish passes. The average of heat input used was of 1.5-1.9 kJ/mm. After welding, the test samples were prepared for microhardness test, Charpy impact test, and microstructural examinations. The results showed that there was a significant reduction of Charpy toughness value due to welding process from 339.22 Joules for base metal to 89.22 Joules and 101.23 Joules for average weld metal and fusion zone consecutively. However, the toughness value between each welding repair showed same pattern with no significant reduction or increment of Charpy impact value. Same pattern also observed on microhardness measurement which revealed no significant fluctuation between each welding repair. Furthermore, the morphology of microstructure present in weld metal and heat affected zone area were also investigated to achieve more understanding regarding the effect of multiple repairs to the properties of Duplex weldment.</em> <em>Bearing in mind that at the moment, carrying out just one repair per welded joint especially for Duplex Stainless Steel is advised as the limiting condition</em>.</p> Febi Dwi Antony, Rini Riastuti, Winarto Winarto Copyright (c) 2019 Febi Dwi Antony, Rini Riastuti, Winarto Winarto http://creativecommons.org/licenses/by-nc-nd/4.0 https://materialmetalurgi.id/index.php/JMMI/article/view/32 Sat, 31 Aug 2019 00:00:00 +0700 Pengaruh Temperatur dan Rapat Arus Terhadap Kekerasan dan Distorsi Kisi pada <i>Hard Chromium Plating</i> pada Baja Karbon Rendah https://materialmetalurgi.id/index.php/JMMI/article/view/34 <p><em>Hard Chromium Plating is one of several coating techniques that has been applied to engineering components. The hard chromium layers have several properties such as, hardness, high corrosion and wear resistance. In fact the quality is determined by several process parameters during electro deposition. In this experiment temperature and current density were varied to observe the effect on the quality of hard chromium layer deposited on a steel base plate. This was to find the appropriate combination of producing deposited layer with the optimum quality. The electroplating process was carried out for 60 minutes at 50, 55 and 60 oC with current density variation of 70, 80 and 90 A/dm2. The specimen were then undergone hardness test and XRD characterization. Maximum hardness measured was 1128 HV this was plated at 55°C with a current density of 80 A/dm2. XRD analysis shown that the increasing hardness of hard chromium plating is related with an increase of microstrain calculated from the diffractogram pattern. </em></p> Riska Rachmantyo, Aditianto Ramelan, Akhmad Zein Eko Mustofa, Asep Ridwan Setiawan Copyright (c) 2019 Riska Rachmantyo, Aditianto Ramelan, Akhmad Zein Eko Mustofa, Asep Ridwan Setiawan http://creativecommons.org/licenses/by-nc-nd/4.0 https://materialmetalurgi.id/index.php/JMMI/article/view/34 Sat, 31 Aug 2019 00:00:00 +0700 Pengaruh Variasi Konsentrasi CN- Pada Proses Pelindian Bijih Au Terhadap <i>Recovery</i> Au, <i>Gangue</i> Ag, Cu dan Fe https://materialmetalurgi.id/index.php/JMMI/article/view/27 <p><em>Gold is a precious metal, valuable, and widely found in Indonesia. Gold metal applications can be found in the jewelry, medical, catalyst and high-tech industries. In this study 35 </em><em>m</em><em>m of gold ore with a level of 15.6 ppm was extracted using NaCN as a lixiviant. The leaching process parameters included variations in 200, 300, and 400 ppm CN</em><em><sup>-</sup></em> <em>concentrations, 48 h</em><em>our</em><em> leaching time and lixiviant pH in the range of 10-11. To increase the extraction rate </em><em>was </em><em>added P</em><em>b</em><em>(NO<sub>3</sub>)<sub>2 </sub>catalyst and 15 ppm oxygen. Characterization results with AAS obtained the highest gold recovery was 88.</em><em>46</em><em>%</em><em> Au</em><em> at CN-300 ppm concentration, leaching time of 8 hours. In addition to gold metal, other metals are also found as gangue such as Ag, Cu and Fe.</em></p> Sutarno Sutarno, Andri Kabarubun, Iskandar Muda, R.M Ario Adisaputro Copyright (c) 2019 Sutarno Sutarno, Andri Kabarubun, Iskandar Muda, R.M Ario Adisaputro http://creativecommons.org/licenses/by-nc-nd/4.0 https://materialmetalurgi.id/index.php/JMMI/article/view/27 Sat, 31 Aug 2019 00:00:00 +0700 Observasi <i>Nanofluid</i> dengan TiO2 sebagai Partikel Nano dan <i>Sodium Dodecyl Benzene Sulfonate </i> sebagai Surfaktan untuk Aplikasi Media <i>Quench</i> https://materialmetalurgi.id/index.php/JMMI/article/view/17 <p>Heating and cooling process in heat treatment is a common process to increase the mechanical properties of steel component. Rapid cooling, or quenching, is needed to change the microstructure to obtain the desire hardness. Recently, nanofluid is widely used as a medium for quenching because of their advantage in heat thermal conductivity compared with conventional medium such as water or oil. Nanofluid is a liquid with high thermal conductivity nanoparticle suspended in the fluid base. The variation of nanoparticles content in nanofluids could control the cooling rate to optimize the desired characteristics of a material. TiO2 is widely used as nanoparticle because of its high thermal conductiviy, relatively cheap and environmental friendly. To improve the suspension of TiO2 nanoparticle in nanofluid, surfactant is added. In this research, Commercial grade TiO2 powder was used as nanoparticle, and common household bodycare which contain Sodium Dodecyl Benzene Sulfonate (SDBS) was used as the source of surfactant. The nanofluid was produced by mixing 100 ml water with 0.1% volume TiO2, and additional 1%, 3%, and 5% SDBS surfactant as variation. Before mixing, the TiO2 powder were milled at 500 rpm for 10 hours. This nanofluid was then used as quenching medium. The steel used as sample in this experiment was S45C medium carbon steel, heated at 1000°C for 1 hour. Scanning Electron Microscope (SEM) was used to determine the TiO2 particle size after milling, and showed roughly less than 100 nm. Microstructure observation showed martensite phase formation after quenching. Hardness test confirmed this phase, showing hardness up to 954 HV after quenching using surfactant added nanofluid.</p> Andreas Sugiarto, Aldi Alfarizi, Luthfi Dali Ahmad, Setyoaji Fajar Negara, Ghiska Ramahdita, Sri Harjanto, Wahyuaji Narottama putra Copyright (c) 2019 Andreas Sugiarto, Aldi Alfarizi, Luthfi Dali Ahmad, Setyoaji Fajar Negara, Ghiska Ramahdita, Sri Harjanto, Wahyuaji Narottama putra http://creativecommons.org/licenses/by-nc-nd/4.0 https://materialmetalurgi.id/index.php/JMMI/article/view/17 Sat, 31 Aug 2019 00:00:00 +0700 Perkembangan Simulasi Korosi – Sebuah Ulasan Ringkas https://materialmetalurgi.id/index.php/JMMI/article/view/28 <p class="Abstract"><em><span lang="IN">Corrosion is metal loss due to interaction with the surrounding environment. The consequences of corrosion are so damaging that they can have an impact on human casualties. A report from NACE in 2002 has shown that corrosion losses in the United States was about 3.1% of Gross Domestic Product (GDP). This figure was expected to increase in 2016 to over 6.2% of GDP. Overall, the losses caused by corrosion have reached 3-4% of the GDP of the industrialized countries. The numbers are very large and therefore, corrosion control are very important to be implemented. In efforts to control corrosion, research in the area has been widely conducted. Experimental research has played a very important role. However, the development of simulations in the world of corrosion is also very promising. Corrosion simulations are developed based on numerical methods. The commonly used numerical method is the boundary element method (BEM). In subsequent developments, the optimization method has also been used in the case of inverse analysis such as corrosion detection. This paper presents briefly the development of corrosion simulation which has been performed by many researchers in efforts to solve various corrosion cases. </span></em></p> <p>&nbsp;</p> Syarizal Fonna, Gunawarman Gunawarman, Syifaul Huzni, Ahmad Kamal Ariffin Copyright (c) 2019 Syarizal Fonna, Gunawarman Gunawarman, Syifaul Huzni, Ahmad Kamal Ariffin http://creativecommons.org/licenses/by-nc-nd/4.0 https://materialmetalurgi.id/index.php/JMMI/article/view/28 Sat, 31 Aug 2019 19:09:09 +0700