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PENGARUH UNSUR TEMBAGA (CU) TERHADAP FLUIDITAS PADUAN AL-SI 11.8 WT% (ADC 12) DENGAN METODE VACUUM SUCTION TEST Suharno, Bambang; Nanda, Is Prima; Arifin, Bustanul; Seto, Demas
Jurnal Energi Dan Manufaktur Vol 1, No.2 Desember 2006
Publisher : Department of Mechanical Engineering, University of Udayana

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Abstract

Al-Si 11.8 wt% alloy which classified to eutectic Al-Si composition usually used to produce a flat casting product with high pressure die casting process. Alloying element become an important things to determine behavior and characteristic of aluminum. Copper added into aluminum to improve strength and hardness, but there has no many studies on the effect of copper on fluidity. This fluidity study is using vacuum suction test method and the microstructure is observed with SEM/EDS. Spectrometer test has been used to find out chemical composition of sample. The result of this study shows that with copper addition from 2.25 wt% to 3.11 wt%, the fluidity value has increased 24.11% on 680oC pouring temperature. On 3.11 wt% copper composition, fluidity value has increased 14.38% from 640oC pouring temperature to 700oC pouring temperature.
MORFOLOGI DAN KARAKTERISTIK LAPISAN INTERMETALIK AKIBAT DIE SOLDERING PADA PERMUKAAN BAJA CETAKAN (DIES) DALAM PROSES PENGECORAN TEKAN PADUAN ALUMINIUM SILIKON Suharno, Bambang; Dimiyati, Rima; Arifin, Bustanul; Harjanto, Sri
Jurnal Teknik Mesin Vol 9, No 2 (2007): OCTOBER 2007
Publisher : Institute of Research and Community Outreach - Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (405.02 KB) | DOI: 10.9744/jtm.9.2.

Abstract

The major mode which lead to die failure in die casting is die soldering caused by the intimate contact between alloy and die at high temperature. It leads to malfunctioning of die inserts that require replacement or repair, thus causing significant decrease in productivity. The effect of melt temperatures on morphology and characteristic of intermetallic layer such as thickness and hardness of intermetallic layer between die surface and aluminum has been studied. This experiment used as-annealed H13 tool steel as die material which dipped into Al-7%Si alloy at 6800C, 7000C, 7200C and Al-11%Si alloy at 6600C, 6800C, 7000C. High melt temperature favored the growth of intermetallic layer due tp the increasie of the diffusion rate of iron and aluminum atoms. Hence, high melt temperature facilitates die soldering. Abstract in Bahasa Indonesia: Umumnya kerusakan cetakan pada industri die casting disebabkan die soldering yang terjadi pada permukaan cetakan yang mengalami kontak langsung dengan logam cair pada temperatur tinggi. Hal ini dapat menyebabkan perlu diadakannya perbaikan atau penggantian cetakan sehingga menurunkan produktivitas. Untuk itu dilakukan penelitian mengenai pengaruh temperatur logam cair (melt) terhadap morfologi dan karakteristik lapisan intermetalik yaitu ketebalan dan kekerasan lapisan intermetalik yang terbentuk antara permukaan cetakan dan logam cair. Pada penelitian ini digunakan baja H13 as annealed sebagai material cetakan yang dicelup ke dalam paduan Al-7%Si pada temperatur 6800C, 7000C, 7200C dan Al-11%Si pada temperatur 6600C, 6800C, 7000C. Peningkatan temperatur logam cair akan meningkatkan laju difusi pertumbuhan lapisan intermetalik karena laju difusi atom-atom besi dan aluminium meningkat. Sehingga ketebalan dari lapisan intermetalik akan meningkat seiring dengan peningkatan temperatur logam cair. Oleh sebab itu, tinggiya temperatur logam cair memper¬mudahkan terjadinya die soldering. Kata kunci: Die casting, die soldering, paduan aluminium silikon, temperatur logam cair, lapisan intermetalik.
Effect of Contact Time on Interface Reaction between Aluminum Silicon (7% and 11%) Alloy and Steel Dies SKD 61 Suharno, Bambang; Nurhayati, Neni; Arifin, Bustanul; Harjanto, Sri
Makara Journal of Technology Vol 11, No 2 (2007)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (355.121 KB) | DOI: 10.7454/mst.v11i2.132

Abstract

Die soldering (die sticking) is a defect of metal casting in which molten metal “welds” to the metallic die mold surface during casting process. Die soldering is the result of an interface reaction between the molten aluminum and the die material. Aluminum alloy with 7 and 11% silicon and SKD 61 die steel are the most common melt and die material used in aluminum die casting. This research is done to study the morphology and the characteristics of the formed AlxFeySiz intermetallic layer during interface reaction at dipping test. The samples of as-anneal SKD 61 tool steel was dipped into the molten of Al-7%Si held at temperature 680oC and into molten Al-11%Si held at temperature 710oC with the different contact time of 10 minutes; 30 minutes; and 50 minutes. The research results showed that the interface reaction can form a compact intermetallic layer with AlxFey phase and a broken intermetallic layer with AlxFeySiz phase on the surface of SKD 61 tool steel. The increasing of the contact time by the immersion of material SKD 61 tool steel in both of molten Al-7%Si and Al-11%Si will increase the thickness of the AlxFeySiz intermetallic layer until an optimum point and then decreasing. The micro hardness of the AlxFeySiz intermetallic layer depends on the content of the iron. Increasing of the iron content in intermetallic layer will increase the micro hardness of the AlxFeySiz. This condition happened because the increasing of Fe content will cause forming of intermetallic AlxFeySiz phase becomes quicker.
PEMBUATAN NPI (5-8% Ni) MENGGUNAKAN HOT BLAST CUPOLA FURNACE KAPASITAS 3 TON/HARI Nurjaman, Fajar; Shofi, Achmad; Astuti, Widi; Suharno, Bambang
Jurnal Teknologi Mineral dan Batubara Vol 14, No 1 (2018): Jurnal Teknologi Mineral dan Batubara Edisi Januari 2018
Publisher : Puslitbang tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (617.472 KB) | DOI: 10.30556/jtmb.Vol14.No1.2018.193

Abstract

Bijih besi nikel laterit merupakan batuan mineral dengan kandungan 10-40%Fe; 0,8-3,5%Ni; dan 1-2%Cr, yang merupakan bahan baku untuk pembuatan Nickel Pig Iron (NPI) yang selanjutnya dapat diolah menjadi besi-baja paduan mengandung Ni dan Cr. Dalam penelitian ini telah dilakukan pembuatan NPI menggunakan teknologi berinvestasi rendah, yaitu hot blast cupola furnace (tungku kupola udara panas) dengan kapasitas 3 ton NPI/hari. Proses aglomerasi bijih nikel laterit menjadi pellet komposit (Ø10-20 mm) terlebih dahulu dilakukan sebelum dilebur ke dalam hot blast cupola furnace. Komposisi (dalam %berat) pellet komposit adalah 85,5% bijih nikel laterit; 12,5% batubara; dan 2% bentonit. Dalam proses peleburan ditambahkan kokas (sebagai bahan bakar dan reduktor) dan batu kapur (sebagai flux) ke dalam tungku tersebut. Rasio penggunaan kokas terhadap pellet komposit adalah 0,4. Penambahan batu kapur (CaCO3) dilakukan untuk memperoleh kondisi basisitas slag 1,0. Aditif berupa MnO2 (39% Mn) juga ditambahkan ke dalam hot blast cupola furnace. Pada proses peleburan, kondisi temperatur udara panas (hot blast) adalah 250-300 ºC. Dari hasil penelitian diperoleh NPI dengan kandungan 5-8% Ni. Penambahan aditif MnO2 sebanyak 1% mampu menekan laju reduksi senyawa besi oksida sehingga mampu meningkatkan kandungan Ni dalam NPI.
THE INFLUENCE OF GRAIN REFINER ON DENDRITE ARM SPACING OF ALUMINUM ALLOY ADC 12 Suharno, Bambang; Nanda, Is Prima; Harjanto, Sri; Lirachandra, Erika
Jurnal Sains Materi Indonesia Vol 8, No 2: FEBRUARI 2007
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (414.608 KB) | DOI: 10.17146/jsmi.2007.8.2.4776

Abstract

THE INFLUENCE OF GRAIN REFINER ON DENDRITE ARM SPACING OF ALUMINUM ALLOY ADC 12. ADC 12 is the common used materials for die casting process in producing automotive components. Grain refiner was added to aluminum ADC 12 to increase mechanical properties by decreasing grain size and improving fine distribution of gas porosity. Grain refiner also give positive effect in aluminum fluidity, where the proper addition of grain refiner will increase the fluidity. The purpose of present research is determining correlation between grain refiner addition and dendrite arm spacing, which also indirectly related to the grain size. 100% scrap of aluminum ADC12 and Al5Ti1B grain refiner were used as raw materials. Melting process has been done in a 1400 gr crucible with cokes and oxygen as the fuming energy. Argon was introduced into crucible at least in 1 minute for degassing. After degassing process accomplished, 0, 0.05, 0.1, 0.15, 0.2 % grain refiner Al5TiB, which have been choosen as experimental variable, were charged into crucible. Vacuum suction machine has been utilized to measure the aluminum fluidity at 680 0C, the common ADC 12 pouring temperature. Samples for microstructural analysis were tooken at the tip of specimen from vacuum suction test. Measurement of dendrite arm spacing (DAS) was conducted by SIGMA SCAN Pro.5 Software. The result indicated that at 680 0C, the addition up to 0.15% Al5Ti1B grain refinement reduced 50% dendrite arm spacing from 8.8 ìm (without grain refiner) to 4.5 ìm. Over 0.15% Al5Ti1B, the refinement stopped and DAS increased caused by the complex intermetallic phase (Ti-Al, Ti-B) has nucleated from the excess grain refiner.
STRUKTURMIKRO DAN SIFAT FISIK-MEKANIK BETON RINGAN TANPA PEMATANGAN DALAM AUTOCLAVE (NON AUTOCLAVED AERATED CONCRETE, NAAC) Harjanto, Sri; Sony, Prima; Suharno, Bambang; Ashadi, Henki W.
Jurnal Sains Materi Indonesia Vol 9, No 2: Februari 2008
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1315.047 KB) | DOI: 10.17146/jsmi.2008.9.2.4746

Abstract

STRUKTURMIKRO DAN SIFAT FISIK-MEKANIK BETON RINGAN TANPA PEMATANGAN DALAM AUTOCLAVE (NON AUTOCLAVED AERATED CONCRETE, NAAC). Pembuatan beton ringan umumnya menekankan pada dua hal, yaitu massa jenis yang serendah mungkin dan kuat tekan yang setinggi-tingginya. Penelitian ini mengamati strukturmakro dan stukturmikro, sifat fisika-mekanika dan keterkaitannya satu sama lain. Dalam penelitian ini, beton ringan dibuat tanpa pematangan dalam autoclave (Non Autoclaved Aerated Concrete, NAAC) dengan penambahan senyawa pengaerasi Al (2 % massa) dan H2O2 (32 % massa) secara terpisah. Alkalinitas campuran beton ringan ini dikontrol dengan penambahan kapur sampai jumlah tertentu. Diperoleh hasil massa jenis beton ringan NAAC dengan senyawa pengaerasi Al dan H2O2 masing-masing adalah 1126 kg/m3 dan 1163 kg/m3. Sedangkan kuat tekan yang dihasilkan dari beton ringan dengan senyawa pengaerasi Al dan H2O2 masing-masing adalah 2,74 MPa dan 3,48 MPa. Massa jenis beton ringan NAAC masih lebih tinggi, sedangkan kuat tekannya relatif lebih rendah dibanding beton ringan dengan pematangan dalam autoclave (Autoclaved Aerated Concrete, AAC). Hasil penelitian ini juga mengindikasikan pengaruh pori terhadap massa jenis dan fasa strukturmikro dengan kuat tekan.
PENGARUH JENIS PADUAN MIKRO Fe-Cr HASIL METODE ULTRASONIK PADA PEMBENTUKAN BONGKAH PADUAN Fe-Cr MELALUI SINTERING DUA TAHAP Silalahi, Marzuki; Untoro, Pudji; Suharno, Bambang; Harjanto, Sri
Jurnal Sains Materi Indonesia Vol 15, No 3: APRIL 2014
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1108.741 KB) | DOI: 10.17146/jsmi.2014.15.3.4353

Abstract

PENGARUH JENIS PADUAN MIKRO Fe-Cr HASIL METODE ULTRASONIK PADA PEMBENTUKAN BONGKAH PADUAN Fe-Cr MELALUI SINTERING DUA TAHAP. Fe-Cr adalah paduan yang memiliki ketahanan pada suhu tinggi dan potensial digunakan sebagai interkonek pada sel bakar Solid Oxide Fuel Cell (SOFC). Pada penelitian ini telah dilakukan sintesis bongkah paduan Fe-Cr dengan menggunakan serbuk paduan mikro Fe-Cr hasil sintesis dengan metode ultrasonik. Metode ultrasonik dimanfaatkan untuk sintesis paduan mikro Fe-Cr melalui penggunaan gelombang suara ultrasonik. Langkah yang dilakukan adalah konsolidasi partikel paduan mikro Fe-Cr melalui kompaksi tanpa lubrikan, kemudian dalam kapsul kaca kuarsa dilakukan proses sintering sampai 1000 oC selama 1 jam, lalu dilanjutkan sintering hingga 1300 oC selama 2 jam, lalu didinginkan dalam tungku. Karakterisasi struktur mikro dilakukan dengan Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Diffraction (XRD) disertai analisis dengan metode Rietveld dan pengukuran densitas sesungguhnya. Partikel paduan mikro Fe-Cr seutuhnya lebih stabil dan konsisten dalam pembentukan fasa bongkah paduan Fe-Cr melalui sintering bertahap. Diperoleh bongkah paduan Fe-Cr homogen tanpa oksida.
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] Lalasari, Latifa Hanum; Yuwono, Akhmad Herman; Firdiyono, Firdiyono; Andriyah, Lia; N, Elfi; Harjanto, Sri; Suharno, Bambang
Metalurgi Vol 27, No 3 (2012): Metalurgi Vol.27 No.3 Desember 2012
Publisher : Pusat Penelitian Metalurgi dan Material - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (643.211 KB) | DOI: 10.14203/metalurgi.v27i3.235

Abstract

STUDI PERBANDINGAN EFEK FOTOKATALISIS Fe2O3-TiO2 HASIL EKSTRAKSI ILMENITBANGKA DAN P-25 DEGUSSA UNTUK APLIKASI PENGOLAHAN LIMBAH CAIR TPACILOWONG. Telah dilakukan penelitian penurunan kadar BOD5, COD, dan TDS dari lindi sampah tempatpembuangan akhir (TPA) Cilowong dengan menggunakan katalis Fe2O3-TiO2 dari hasil proses ekstraksi ilmenitBangka Indonesia dan TiO2 P-25 Degussa (komersial). Proses dilakukan dalam reaktor fotokatalitik berukuran30 x 15 x 20 cm dengan radiasi sinar UV 50 watt selama 90 menit pada temperatur kamar dan setiap 15 menitdiambil sampel untuk dilakukan analisa BOD5, COD, dan TDS. Variabel percobaan yang digunakan adalah rasiovolume (v/v) lindi/H2O sebesar 1/4; 1/8; 1/12; 1/16 dengan jumlah katalis yang digunakan masing-masingsebanyak 1 gram. Hasil penelitian pada rasio volume (v/v) lindi/H2O sebesar 1/16 menunjukkan penurunanBOD5, COD, TDS masing-masing sebesar 45; 90,43; 100 % untuk katalis Fe2O3-TiO2 dan sebesar 80,6; 75; 100% untuk TiO2 P-25 Degussa. Penelitian juga memberikan gambaran bahwa mineral Ilmenit Bangka Indonesiaberpotensi besar sebagai bahan baku dalam pembuatan katalis Fe2O3-TiO2. AbstractThe current work presents the results of investigation on the decreasing levels of BOD5, COD, TDS ofleachate on the landfill (TPA) Cilowong by using Fe2O3-TiO2 catalyst derived from the extraction process ofBangka Indonesia ilmenite as well as commercial TiO2 P-25 Degussa catalysts. The measurement wascarried out in a photocatalytic reactor of 30 x 15 x 20 cm equipped with a 50 watt UV radiation. The processwas performed for 90 minutes at room temperature, and the samples were taken every 15 min for BOD,COD, and TDS analyses. The ratio of leachate to H2O (%v) was varied as 1/4; 1/8; 1/12 and 1/16, with theamount of catalyst used was 1 gram. The result on ratio of leachate to H2O of 1/16 showed the decrease inBOD5, COD, TDS with the use of Fe2O3-TiO2 catalysts by 45; 90.43 and 100% for Fe2O3-TiO2 catalysts,while with the use of Degussa P-25 TiO2 catalysts the decrease in BOD5, COD, TDS reached by 80.6; 75 and100%, respectively. On the basis of findings, it is shown that Ilmenite Bangka Indonesia has great potentialas a raw material for synthesizing the Fe2O3-TiO2 catalysts.
ULTRASONIC TREATMENT EFFECT ON THE CONSOLIDATION OF Fe-Cr PARTICLE MIXTURES AFTER COMPACTION AND SINTERING PROCESS Silalahi, Marzuki; Untoro, Pudji; Suharno, Bambang; Harjanto, Sri
Metalurgi Vol 29, No 2 (2014): Metalurgi Vol.29 No.2 Agustus 2014
Publisher : Pusat Penelitian Metalurgi dan Material - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (449.765 KB) | DOI: 10.14203/metalurgi.v29i2.289

Abstract

ULTRASONIC TREATMENT EFFECT ON THE CONSOLIDATION OF Fe-Cr PARTICLEMIXTURES AFTER COMPACTION AND SINTERING PROCESS. Fe-Cr microalloys which obtained byultrasonic method are the initial cores for the consolidation process. Therefore its facilitate the formation of thehomogeneous bulk of Fe-Cr alloy with a stable phase. In this research, the synthesis of bulk of Fe-Cr alloy fromthe particles mixture of (Fe+Cr) as the ultrasonic treatment results has been carried out. The particlesconsolidation has been carried out through a process of compaction without adding any lubricants and followedby sintering process in the quartz glass capsules by using induction furnace at 1300 °C. Consolidation of mixtureof Fe-Cr particles that have not undergone previous ultrasonic treatment is also made for a comparison. Theinvestigation by using the SEM (scanning electron microscope)- and density measurements method werepreformed on the Fe-Cr green powders compaction. The bulk of Fe-Cr alloys that are produced trough sinteringprocess was observed using SEM-EDS (energy dispersive spectroscopy), XRD (x-ray diffraction), and densitymeasurements method. The bulk of Fe-Cr alloy prepared with ultrasonically treated Fe-Cr microalloy powders,is more homogeneous in composition and has a better phase stability in comparison to Fe-Cr powders preparedwithout the ultrasonic treatment. Production of bulk Fe-Cr alloy in quartz glass capsule during the sinteringprocess has produced Fe-Cr alloy without oxides.
The potential of carbonate apatite as an alternative bone substitute material Rahyussalim, Ahmad Jabir; Supriadi, Sugeng; Marsetio, Aldo Fransiskus; Pribadi, Pancar Muhammad; Suharno, Bambang
Medical Journal of Indonesia Vol 28, No 1 (2019): March
Publisher : Faculty of Medicine Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (339.221 KB) | DOI: 10.13181/mji.v28i1.2681

Abstract

Bone reconstructive surgery has become a common procedure, and bone transplantation has become the second most frequently performed tissue transplantation procedure worldwide. Therefore, the need for bone substitute materials has increased. Artificial bone substitutes exhibit osteoconductive properties and feature several advantages, including abundant resources, low cost, and low donor site morbidity. Carbonate apatite (CO3Ap) is a calcium phosphate ceramic that can be used as a synthetic bone graft. The carbonate content of this ceramic is similar to that of bone apatite. In this review, we show that carbonate apatite can be degraded given its chemical reactivity in a weakly acidic environment and through osteoclast resorption. Moreover, it is osteoconductive and promotes bone tissue formation without fibrotic tissue formation. Additionally, microstructural analysis revealed that new bone tissue is formed within the bone graft itself.