Material Strength Analysis on Track Shoe Excavator Using Abrasive Wear Testing Using Pin-on-Disk Method

Undercarriage excavator costs a lot for the maintenance and repair of the overall cost of excavator maintenance and repair. One part of the undercarriage excavator that mostly requires maintenance is the track shoe. Track shoe is the crawler or outer wheel of excavator that serves as an excavator drive. This part is always in direct contact with the soil resulting wear and tear. This research discussed the comparison of track shoe material from the market products and the material that had already been quenching with the medium of water. The material in use was AISI 1526. The analyzing processes used micrography testing, hardness testing, wear and tear testing and corrosion testing. Examination of the microstructure of the sample was conducted using optical microscope, the hardness sample testing was conducted using rockweld hardness tester, wear and tear testing was conducted using pin-on-disk method, and corrosion testing was conducted using potentiodynamic polarization method. From the analysis results, the hardness value for the market product material was 41 HRC and the heat treatment material was 48.33 HRC. The rate of wear and tear for the market product material was 4.02x10-5 mm3/mm and the heat treatment material was 3.30x10-5 mm3/mm. The result of corrosion testing for the market product material was 0.52  and the heat treatment material was 0.38 . From the testing results, the hardness value was inversely proportional to the wear and tear and corrosion value; the harder the material, the less the rate of wear and tear. Keywords: AISI 1526, track shoe, excavator, micro structure, wear and tear testing, hardness testing, corrosion testing, pin-on-disk, potentiodynamic polarizatio

Reliability Analysis of Hydraulic Components and Excavator Engine in Maintenance of Mine Heavy Equipment

This research aims to analyze the reliability analysis of hydraulic components and excavator engine in maintenance of mine heavy equipment. In this research determined reliability and critical component replacement interval of hydraulic system and engine unit excavator. Determination critical component replacement interval of hydraulic system and engine was done by using minimal maintenance cost model. Reliability value of excavator EH 4 is the lowest compared to EH 3 and EH 5 at the time t is equal to 96 hours. Reliability value of Excavator EH 4 is 0.002, EH 5 is 0.33 and EH 3 is equal to 0.49. Component with maximum replacement interval is fuel filter Excavator EH 4 that is equal to 432 hours and component with minimum replacement interval is component Hose Pilot of excavator EH 3 that is 22398 hours Keywords: Reliability, Critical components, hydraulic, excavato

PENGARUH VARIASI KECEPATAN PUTAR DALAM METODE STIR CASTING TERHADAP DENSITAS DAN POROSITAS Al- SiC UNTUK APLIKASI BLOK REM KERETA API

Penelitian ini dilakukan untuk mengetahui tentang densitas dan porositas pada Al-  SiC yang dihasilkan dari proses pengecoran dengan metode stir casting dengan variasi putaran 300, 500, dan 700 rpm dengan lama waktu pengadukan 10 menit. Pada penelitian ini Al yang digunakan adalah Al hasil limbah produksi dengan penambahan SiC sebesar 10% sebagai penguat yang dicampurkan pada saat pengecoran. Hasil penelitian ditemukan densitas Al-SiC untuk semua variasi putaran, lebih rendah dari besi cor  yaitu 2,75; 2,69 dan 2,66 g/cm3, itu berarti bahwa blok rem kereta api yang terbuat dari Al- SiC lebih ringan massanya daripada blok rem kereta api yang terbuat dari besi cor ( 7,2 g/cm3). Dengan harapan bahwa semakin ringan komponen kereta api akan semakin meningkatkan kehandalan kinerjanya.  Sedangkan  untuk porositas, Porositas yang diperoleh nilainya hampir sama yaitu 0,9900; 0,9902 dan 0,9903. Nilai porositas yang diperoleh dari variasi putaran sangat rendah, sehingga proses pengecoran dengan stir casting dianjurkan untuk mengurangi porositas. Kata kunci: Al- SiC, Stir Casting, densitas, porositas

PENGARUH ADITIF Zn2+ TERHADAP PEMBENTUKAN KERAK GIPSUM DALAM PIPA

Kerak gypsum (CaSO4.2H2O)  yang terjadi dalam pipa sangat merugikan bagi industri karena mengakibatkan penyempitan penampang, mempertebal dinding, menghambat  pemindahan panas dan memperlambat waktu proses. Oleh karenanya, kerak gipsum harus dicegah atau dihambat pertumbuhannya. Pertumbuhan kerak gipsum dipengaruhi oleh konsentrasi, temperatur dan laju alir serta impuritas. Penelitian ini bertujuan untuk mengetahui pengaruh aditif Zn2+ terhadap pembentukan kerak gipsum. Percobaan pembentukan kerak gipsum dilakukan dengan mereaksikan larutan  CaCl2.2H2O dengan  larutan  NaSO4 dalam alat uji  yang telah dirancang. Percobaan dilakukan dengan konsentrasi aditif 0 ppm  –  10 ppm pada suhu kamar, konsentrasi Ca2+3500 ppm, laju alir 30 ml/menit dan pipa uji stainless steel.   Hasil dari penelitian ini menunjukkan penambahan  aditif Zn2+ mengakibatkan naiknya waktu induksi dan menurunnya massa kerak dan menjadikan ukuran kristal lebih  kecil dan pendek. Hasil pengujian morfologi, komposisi dan kemurnian menunjukkan bahwa kerak hasil percobaan benar-benar gipsum. Keywords : additive, gypsum, scale, zin

Influence of Flow Rates and Copper (II) ions on the Kinetics of Gypsum Scale Formation in Pipes

Experiments were performed in a piping system to examine the effects of flow rates and Cu2+, a common metal ion in wastewater, on the kinetics of gypsum (CaSO4.2H2O) scale formation. The scaling was monitored by measuring the decrease in Ca2+ concentrations, [Ca2+], of the scaling solution. AAS analysis shows that [Ca2+] reduces progressively after a certain induction time, during which time the concentration remains steady. Thus, the gypsum precipitation which leads to scaling in pipes does not occur spontaneously. Higher impurity concentrations (0 to 10 ppm Cu2+) result in longer induction time (26 to 42 min), which indicate that Cu2+ could inhibit the scale formation. Impurity concentrations and the scale mass generated are negatively correlated. Reduction in scale mass was as high as 61% depending on impurity concentrations and flow rates. Data of [Ca2+] versus time were used to calculate the reaction rate of the gypsum precipitation which led to scaling. It was found that the reaction follows a first order kinetics with respect to [Ca2+], with rate constants ranging between 5.28 and 7.37 per hour, which agree with most published values for mineral scale formation

Simulation of Excavator Bucket Pressuring Through Finite Element Method

Excavator bucket tool is one of the most important parts of an excavator. It is made of steel mixture. It is commonly equipped with protruding teeth on its cutting side to breakdown hard materials and also to prevent dryness and damage of the bucket. Excavator bucket tooth must have supporting geometrical shape to penetrate and to endure the digging process on the ground, gravels, stones, or any other abrasive field. It is because of the field’s natural characteristic when the bucket tool grinds the material. Mixed iron is common to be used as excavator bucket tool’s material because it is easy to get and economic. High hardness value is also needed on the surface that transports hard material such as mining equipment. Therefore, an accurate analysis should be done to determine the suitable material on this field. Design and analysis were done by using Computer-Aided Engineering (CAE) Abaqus 6.10 application to get the maximum tension as the result of loading. Analysis process to get the tension was done by adding 8285.06 N weight forces in static condition with the angle of 32o to the horizon. From the analysis it could be known that maximum tension experienced by excavator bucket tooth is 209.3 MPa, and it is still below the Maximum Equivalent von Mises stress so the design could be categorized as saf

A temperature-mediated precipitation of struvite-family crystals in wastewater

The paper presents results of the investigation into the temperature mediated mineralogical formation of struvite family crystals in a synthetic wastewater. The scale-forming solution was set-up by mixing solutions of MgCl2 and NH4H2PO4 with Mg+2, NH4 + and PO4 -3 in a molar ratio (MAP) of 1:1:1. The temperature was altered: 30, 35 and 40 OC. The initial pH of the solution was set up in 9.0. SEM (equipped with EDX) analysis revealed that the crystals have a needle like-shaped morphology, and contained Mg, K, P, and O as the main composition. The Rietveld analysis of the XRPD pattern confirmed that the major phase of struvite, and struvite-(K) formed in the precipitating solids. Apparently, bobierrite and newberyte were other phosphate minerals formed at the temperature of 35 OC. Analysis of this experimental data suggested that the temperature-mediated crystallization process yielded a potential optimization of struvite precipitation

Optimalisasi Proses dan Sifat Gelas Keramik dari Abu hazard Incinerator (Optimized Processing and Properties of Glass-Ceramic from Hazardous Incinerator Ash)

The incineration is potentially attractive technique for use in the processing of organic waste materials, which can reduce the big volume of waste fastest. This technique is of particular interests if applied in the big town of Indonesia due to the high density of population and the limited availability of space for landfilling. However incineration leaves considerable amount of filter ashes and residue containing significant concentrations of heavy metals and organic pollutant that are considered very hazardous for environment. The alternative solution in isolating of hazardous waste is to form glassy state by using vitrification process. Studies have shown that vitrification process are effective in reducing the organic pollutants and the heavy metals by producing inert vitreous product that can be used for developing glass-ceramics. It is due to that vitrification involves relatively high costs, therefore the use of the process can be fully justified only if high quality product with optimised properties can be produced. Therefore this research was performed to optimise processing of hazardous incinerator ash and properties of glass-ceramics with low leachability of hazardous element. The study involved development of small-scale incinerator, processing experiments of the domestic waste; characterisation measurements; determination of selected properties of the glass-ceramics developed. The principal focus of the research was to develop glass-ceramic materials from the incinerator ash by using vitrification process. The research project was initiated by the development of a small-scale incinerator for processing organic solid waste in the Materials Laboratory. Filter ash and residue produced were subsequent used for raw materials of the glass-ceramics investigated. A Lithium-Aluminate-Silicate glass-ceramics with controlled hazardous composition from the incinerator ash was obtained by addition of 4-wt % Lithium Sulfate with (i) low density and (ii) crystalline structure. Specifically, the effects of vitrification on the complete destruction of organic pollutant and selected properties are addressed. X-ray diffraction (XRD) analysis was utilised to identify crystal structure of the materials. Physical (density and porosity) and mechanical properties (strength) was evaluated by Archimedes method and three-point bend testing, respectively. The result indicates that the vitrification process are very promising solution to reduce the hazard component by forming a glass-ceramic materials. The synthesis of the LAS glass-ceramics could be performed in the temperature range 850°C-1200°C. In the diffraction pattern, evidence of crystallisation in the materials is provided, but the crystal belonging to the LAS (Li20-Al203-Si02) system was still questionable. The future for these materials would appear to be bright, and as environmental considerations continue to put pressure onto waste disposal, such as innovative recycling technology, could become increasingly commonplace. Also various applications of the materials could be developed as a paving material for roads or rooftops. There is great deal of expectation being placed on these materials from the waste treatment aspect and recycling. Teknik pembakaran sampah dengan incinerator merupakan metode yang sangat effektif untuk diterapkan dalam mengolah sampah organik karena kemampuan menurunkan volume sampah secara cepat sebelum dibuang ketempat pembuangan akhir (TPA). Metode demikian sangat cocok jika diterapkan di kota¬kota besar di Indonesia karena tingkat kepadatan penduduk yang relatif tinggi serta keterbatasan lahan pembuangan sampah akhir. Akan tetapi teknik pembakaran sampah masih menyisakan persoalan seperti abu terbang dan residu sisa yang biasanya masih mengandung sejumlah logam berat dan polutan organik yang mana dianggap sangat berbahaya bagi lingkungan. Salah satu cara penyelesaian alternatif dalam mengisolasi logam berat ini adalah dengan merubah abu menjadi bahan baku gelas dengan suatu proses vitrifikasi. Dan sejumlah studi telah menemukan bahwa proses vitrifikasi dikenal sangat effektif dalam menurunkan polutan organik dan logam berat serta menghasilkan bahan bahan baku gelas yang murah dan ramah lingkungan, sehingga dapat dipergunakan untuk pengembangan bahan gelas keramik. Akan tetapi proses vitrifikasi memerlukan pemanasan pada temperatur tinggi (>1200 °C), maka proses ini seringkali dianggap tidak hemat energi dan kemungkinan tidak ekonomis pada skala kecil. Sehingga optimalisasi proses dalam membentuk gelas-keramik dan sifat-sifat teknisnya menjadi perhatian utama. Oleh karena itu penelitian ini dilakukan untuk mencoba memperoleh hasil optimal didalam memproses pembakaran sampah organik. Penelitian yang dilakukan meliputi sejumlah kegiatan antara lain pembuatan incinerator skala laboratorium untuk pembakaran sampah domestik, kemudian dilanjutkan kaji eksperimen bahan abu, karalcterisasi, serta evaluasi sifat-sifat teknis tertentu dari produk gelas keramik. Fokus utama dari penelitian ini adalah memanfaatkan abu incinerator sebagai bahan baku gelas-keramik yang murah dan ramah linkungan dengan suatu proses vitrifikasi. Kegiatan penelitian ini diawali dengan pembakaran sampah organik yang diperoleh dari tempat pembuangan akhir sampah. Hasil abu terbang yang terfilter dan residu selanjutnya dipergunakan sebagai bahan baku gelas-keramik. LAS (Li20-Al203-Si02) gelas keramik dengan kontrol komposisi hazard dari abu incinerator dikembangkan dengan tambahan 4-wt % Lithium Sulfate (Li2SO4•1120) untuk memperoleh gelas keramik dengan (i) masa jenis rendah dan (ii) struktur kristal. Secara khusus dikaji pengaruh vitrifikasi terhadap pelepasan polutan dan sifat tertentu produk gelas-keramik. Selanjutnya analisa diffraksi sinar-x (XRD analysis) digunakan untuk identifikasi struktur kristal dari material. Sifat fisik (density and porosity dan mekanik (strength) dievaluasi dengan metode Archmides dan three-point bending test. Hasil penelitian yang diperoleh menunjukkan bahwa proses vitrifikasi merupakan proses yang layak dipertimbangkan dalam menurunkan polutan berbahaya dengan merubah bahan abu menjadi produk gelas-keramik. Sintesis LAS gelas keramik dapat diperoleh pada kisaran temperatur 850°C-1200°C. Didalam pola diffraksi sinar-x memperlihatkan secara jelas keberadaan struktur kristal didalam material, tetapi struktur kristal termasuk dalam sistem LAS (Li20- Al203-Si02) masih menjadi pertanyaan. Dimasa datang material ini memiliki potensi yang sangat baik karena adanya pertimbangan tekanan regulasi lingkungan dalam hal pembuangan bahan limbah. Selain itu material yang diperoleh dapat diterapkan untuk bahan paving jalan serta bangunan. Ada suatu harapan yang besar pada metode dan produk material ini jika ditinjau dari aspek pengeolahan limbah serta daur ulang

Development Of Fine Powder Deposition Method Applicable To Multi Material Micro Fabrication (MMMF)

Reducing dimension and multiplying functional aspect of engineering product is a mark of a modern technology product. Therefore, research of micro machining and smart material is an important step to develop the future manufacturing process. Layered manufacturing is one of the propective process of it. Research of powder deposition is a key of developing multi material micro fabrication. This research was implemented in four steps including materials preparation and characterization, design and manufacturing experiment apparatus, wall friction-flow ability test and design-manufacturing MMMF machine including the mechanical, electronics and software system. The research was initiated by study observation to find information about characteristic of fine powder and method of reducing the cohesiveness. By sieving process, powder was separated into 4 particle sizes including -34, 34-60, 60-74, 74-104 micron. Particle shapes were observed using optical microscope. Wall friction test was performed to observe the effect of wall surface roughness, particle size and material powder on mass flow characteristic, by Jenike method. Flow ability test was carried out to yield the powder flow consistency by varying the particle sizes, models of screw feeder geometry, installing blender mechanism, reducing the particle cohesiveness and the wall friction test parameters (powder quantity in hopper and wall surface roughness). For these experiments, rotation of the screw feeder was fixed at 236 rpm. By plotting the experimental data, the optimum parameter of powder mass flow can be determined and it was tested by varying rotation of the screw feeder. The experimental results show that the mass flow characteristic is affected by wall surface roughness and particle size. Effect of powder quantity in hopper can be eliminated by installing blender mechanism; it can also reduce the compaction of the powder around nozzle orifice so that the mass flow can be increase. Mass flow characteristic is also affected by hopper angle, in which the optimal angle is achieved at 25.67o (by variation of 20.6o, 22.62o and 25.67o). Powder mass flow was caused dominantly by stimulating rotation of the screw feeder, it is not by helicoidal surface of the screw feeder. Powders trapped in helicoidal slot drive around particle caused by geometric interlocking. However, increasing screw feeder diameter is an effective way to increase the mass flow of smaller particle size (in this chase smaller than 60 micron). Preheating process gives the effective method to increase the mass flow, particularly for small particle (smaller than 60 micron). By considering these parameters, mass flow capacity can be arranged effectively by controlling rotation of the screw feeder