Metallurgy Commons^™

Thermodynamic Analysis Of Rare Earth Chlorination And Bromination Processes, Katie Lyons, Jerome Downey, Dan Gaede, Bryce Ruffier

2015 Undergraduate Research

Research funded by the Army Research Laboratory (ARL), the Metallurgical and Materials Engineering Department at Montana Tech investigated various methods of extracting and refining rare earth elements (REEs) from mineral ores and concentrates. Extensive thermodynamic, thermogravimetric and differential thermal analyses were performed to evaluate the relative stabilities of various REE compounds in order to assess potential methods for selective separation and recovery of specific REEs. Conversion of rare earth oxides (REO) to rare earth chlorides or bromides is a possible initial step in pyrometallurgical and hydrometallurgical processing of REEs. REO can be converted to chlorides or bromides by roasting in …

Sustainable Disposal Of Coal Processing Waste Streams, Mohammad Rezaee

Theses and Dissertations--Mining Engineering

Modern coal preparation facilities incorporate a wide array of solid-solid and solid-liquid separation processes for rejecting mineral matter to meet market specifications. The coarse mineral matter is typically placed into engineered refuse piles whereas the fine refuse is either stored in impoundments or co-disposed with the coarse refuse. The discharge water from the refuse material represents an environmental concern due to the potential release of trace elements, and the subsequent elevation of total dissolved solids and conductivity. The research findings reported in this dissertation addresses sustainable coal processing waste disposal through using strategies aimed at minimizing the environmental impacts. To …

Containment Materials For Thin-Strip Casting Of Steel, Abhishek Kumar

Doctoral Dissertations

"The focus of this research was to investigate the corrosion behavior of BN-based and ZrO₂-C refractories by molten steel. These refractories are used as side-dam and core-nozzle in the thin-strip casting of steel. The improvement and development of these refractory components will increase the process efficiency by prolonging the refractory service life.

The first part of this study focused on interaction of BN-ZrO₂-SiC side-dams with steel-inclusion system in a laboratory setup under argon gas environment. It was observed that corrosion of this ceramic was severe in contact with steel compared to slag/inclusion.

The second part of …

Formation And Evolution Of Spinel In Aluminum Killed Calcium Treated Linepipe Steels, Obinna Adaba

Masters Theses

"Magnesium aluminate (Spinel) inclusions have been observed to cause hook crack in line pipe steels. These inclusions are typically formed during liquid steel processing at the ladle metallurgy furnace (LMF) and subsequently modified by calcium to form less harmful liquid inclusions. Unfortunately, spinel inclusions are still sometimes observed in samples taken from the tundish and coil after calcium treatment.

The formation and evolution of spinel inclusions during liquid steel processing at two industrial mini mills was investigated by analysis of lollipop samples taken at different stages of the steelmaking process. The effect of reoxidation on the formation of spinels after …

Factors Affecting The Heat Transfer During The Dip Testing Of Potential Third Generation Advanced High Strength Steels, Kramer Michael Pursell

Masters Theses

"A dip tester was designed and built at Missouri University of Science and Technology to test the effects of the primary alloying elements (Mn, Si, and Al) of Fe-Mn-Al-Si-C type 3rd generation advanced high strength steel (AHSS) alloys, dipping superheat, and dipping speed on the heat transfer during rapid solidification. The difficulties associated with casting 3rd generation AHSS were compiled as well to serve as a best-practices guide. An extensive list of potential 3rd generation AHSS alloys was developed and tested, and the effects of various dip testing parameters were examined.

Manganese was found to increase the heat flux by …

Understanding Impurities In Copper Electrometallurgy, Paul Laforest

Masters Theses

"This work involves examining two industrial reports of methods to handle impurities in copper electrowinning and electrorefining. The first part evaluates the addition of Hydrostar, Cyquest N-900, DXG-F7, and Guartec EW to copper electrowinning electrolyte to affect MnO₂ deposition on coated titanium anodes (CTAs). The second part examines the effects of anode chemistry and thiourea addition on the ductility of electrorefined copper starter sheet.

In part one, a laboratory cell was used to simulate a short cycle electrowinning cell via chronopotentiometric operation with an IrO₂-Ta₂O₅ CTA at 40⁰C. A cyclic voltammetric sweep was applied …

The Examination Of Stress Corrosion Cracking In High Strength Carbon Steel Through Combined Mechanical-Electrochemical Testing, Jacob Sines

Williams Honors College, Honors Research Projects

Through the analysis of materials and environments seen in industry a better understanding of the fundamentals behind degradation mechanisms can be observed. The scope of this project was to better understand the fundamentals behind the degradation of high strength pipeline steels in a lab setting to simulate an environment seen in industry. Specifically the degradation mechanisms of high and nearly neutral pH stress corrosion cracking were examined in environments that simulated oil and gas pipelines buried in soil. Experimentation was carried out utilizing X65 carbon steel specimen, a Gamry potentiostat, a CORTEST proof ring, a CORTEST slow strain rate machine, …

Nanomechanical And Scaling Behavior Of Nanoporous Gold, Nicolas J. Briot

Theses and Dissertations--Chemical and Materials Engineering

Nanoporous metals have recently been drawn significant interest in various fields of research. Their high surface-to-volume ratio present a strong potential for applications in sensing, catalysis, micro-electromechanical systems (MEMS) and even in the medical field. However, the mechanical properties of nanoporous metals have not yet been well determined, as conducting mechanical tests was found to be challenging. Scaling relations linking the mechanical properties of porous materials to those of their dense counterparts are successfully and widely used for many porous metals. However, their applicability to nanoporous metals have recently been questioned, as estimations from the classic scaling relations were found …

Engineered Surface Properties Of Porous Tungsten From Cryogenic Machining, Julius M. Schoop

Theses and Dissertations--Chemical and Materials Engineering

Porous tungsten is used to manufacture dispenser cathodes due to it refractory properties. Surface porosity is critical to functional performance of dispenser cathodes because it allows for an impregnated ceramic compound to migrate to the emitting surface, lowering its work function. Likewise, surface roughness is important because it is necessary to ensure uniform wetting of the molten impregnate during high temperature service. Current industry practice to achieve surface roughness and surface porosity requirements involves the use of a plastic infiltrant during machining. After machining, the infiltrant is baked and the cathode pellet is impregnated. In this context, cryogenic machining is …

Metallurgical Optimization Of High Strength Cast Steels With Stage I Tempering, Terrell Owen Webb Jr.

Doctoral Dissertations

“Eglin steel was developed by the U.S. Air Force and Ellwood National Forge Company as a cost-effective, ultrahigh strength steel for use in armament, aerospace, and commercial applications. Eglin steel has been successfully substituted for high alloy steels, such as AF1410 and HP-9-4-20/30, to produce the casing for “bunker buster” bombs where penetration of concrete barriers and rock at high velocity ( > 1000 ft/sec) is desired. Unlike AF1410 and HP-9-4-20/30, Eglin steel is low nickel (nominal 1 wt.%) and contains no cobalt. Given the successful performance of Eglin steel in the casings applications, the Department of Defense has directed that …

Influence Of Spatial Variations Of Railroad Track Stiffness And Material Inclusions On Fatigue Life, Celestin Nkundineza

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Railroad transportation is very important for economic growth and effective maintenance is one critical factor for its economic sustainability. The high repetitive forces from a moving railcar induce cyclic stresses that lead to rail bending and potential deterioration due to fatigue crack initiation and propagation. Previous research for prediction of fatigue life has been done under the assumptions of a uniform track bed and a homogeneous rail. However the spatial variation of the track stiffness is expected to increase the maximum stresses in the rail and, therefore, accelerate the fatigue process. The research described in this dissertation is focused on …

Preliminary Investigation Into The Cause Of Pinhole Porosity In Aluminum Metal Castings From Serpentine Impurities In Olivine Sand, Brodie J. Biersner

Dissertations and Theses @ UNI

The problem addressed in this study is how contaminates in the foundry molding aggregate olivine, affect aluminum castings during the casting process. This research will concentrate on hydrated contaminates, specifically the mineral serpentine. The purpose of this research is to better understand how hydrated minerals contribute to the generation of pinhole porosity defects during the casting process. Understanding how impurities in foundry aggregates affect the casting process would aid in the reduction of scrap caused by core and molding sands, ultimately providing savings to the casting manufacturer.

A foundry grade olivine was compared to a new source of olivine to …

Design Of Gan-Based Low-Loss Y-Branch Power Splitter, Retno Wigajatri Purnamaningsih, Irma Saraswati, Nji Raden Poespawati, Elhadj Dogheche

Makara Journal of Technology

We present a Y-branch power splitter design with a multimode section using GaN on Sapphire at telecommunication wavelength. The GaN sample optical properties were also investigated, resulting in a refractive index for the GaN layers nTE=2.289±0.001 and nTM=2.324±0.00. Optimization of the structure parameters for this structure was conducted accurately using BPM methods. The results demonstrated the possibility of realizing a GaN-based Y-branch power splitter for various applications.

Ultra-Wideband Notched Characteristic Fed By Coplanar Waveguide, Rastanto Hadinegoro, Yuli Kurnia Ningsih, Indra Surjati

Makara Journal of Technology

In this paper, a novel Ultra-Wide Band (UWB) notch patch antenna with co-planar waveguide (CPW) fed is presented. This antenna only used one layer and the patch antenna is constructed on the first layer and back to back with CPW fed and bottom part is ground plane. The width notch is used to achieve the UWB characteristic. The results shown that the impedance bandwidth is 1130 MHz (1.662–2.792 GHz) or about 50.7% for VSWR <2.

Analysis Of Vibration Generated By The Rubbing Of Flat Surfaces, Zahrul Fuadi

Makara Journal of Technology

Among the phenomena that occur as a result of contact between two surfaces is friction sound, in which surface roughness is of great importance. In this study, the parameter of contact stiffness is used to explain the frequency characteristic of vibration generated by the rubbing of flat surfaces under a small load. A 3-disk configuration rubbing method was used, which provides a unique characteristic of the system's frequency response function containing specific information about the rubbing vibrations. It is shown that the peak frequency of the rubbing vibration can be explained by using a two-degrees-of-freedom model incorporating the parameter of …

Endoscopic Application Of A Compact Compound-Eye Camera, Keiichiro Kagawa, Shoji Kawahito

Makara Journal of Technology

A multi-functional compound-eye endoscope enabling multi-spectral imaging and variable field-of-view is presented, which is based on a compact compound-eye camera called TOMBO (thin observation module by bound optics). Narrow-band filters attached to some lenses provide snap-shot multi-band images. Fixed and movable mirrors are introduced to control the field of view, which realizes several observation modes such as three-dimensional shape measurement, wide field-of-view, and close-up observation.

Development Of The Soekarno–Hatta International Airport Rail Link Project Using The Value Engineering Method: Creating Value For Money, Mohammed Ali Berawi, Bambang Susantono, Suyono Dikun, Tommy Ilyas, Herawati Zetha Rahman, Abdur Rohim Boy Berawi, Teuku Yuri Zagloel, Perdana Miraj, Jade Sjafrecia Petroceany

Makara Journal of Technology

Soekarno–Hatta Airport is the main gateway for international flights to Greater Jakarta. Its accessibility depends on the inter-city and Sedyatmo toll roads, which causes congestion in peak hours, leading to uncertainty about travel times. The Soekarno–Hatta International Airport Rail Link (SHIARL) is proposed as an alternative mass transportation project, which is expected to provide accessibility and mobility for people and goods to and from the airport. Previously, the project was unattractive to private investors as it was technically and financially unfeasible. Therefore, this research aims to improve the feasibility of the Soekarno-Hatta International Airport Rail Link (SHIARL) by using a …

The Mechanical And Tribology Properties Of Sputtered Titanium Aluminum Nitride Coating On The Tungsten Carbide Insert Tool In The Dry Turning Of Tool Steel, Esmar Budi, Mohd. Razali Bin Muhamad, Md. Nizam Bin Abdul Rahman

Makara Journal of Technology

The effect of the sputtering parameters on the mechanical tribology properties of Titanium Aluminum Nitride coating on the tungsten cabide insert tool in the dry turning of tool steel has been investigated. The coating was deposited using a Direct Current magnetron sputtering system with various substrate biases (-79 to -221 V) and nitrogen flow rates (30 to 72 sccm). The dry turning test was carried out on a Computer Numeric Code machine using an optimum cutting parameter setting. The results show that the lowest flank wear (~0.4 mm) was achieved using a Titanium Aluminum Nitride-coated tool that was deposited at …

Modified Design Of Pin-On-Ring Tribometer For Hip Joint Prostheses Measurement; Case Study On Salat Activity, Muhammad Khafidh, Jamari Jamari, Sulardjaka Sulardjaka, Mohamad Tauviqirrahman, Emile Van Der Heide

Makara Journal of Technology

Total hip replacement (THR) is one of the most successful orthopedic surgical procedures for replacing a broken hip joint. In THR, wear may occur at the articulating surface of the acetabular cup and the femoral head. In Indonesia, the country with the largest Muslim population in the world, most of the inhabitants do salat (praying) every day. THR users are banned from doing salat for fear it will damage the hip joint prostheses. The previous wear calculation methods on the hip joint prostheses use the gravimetric, coordinate measuring machine (CMM), profiler, and geometric method. The disadvantages of the previous methods …

Continuous Production Of Nanotubes And Carbon Clusters By Use Of The Revolver-Injection-Type Arc Jet Producer, Tetsu Mieno, Naoki Matsumoto, Takahashi Tomie, H. Inoue

Makara Journal of Technology

Efficient and continuous production of fullerenes, single-walled carbon nanotubes (SWNTs), and carbon nano-particles has been developed by the JxB arc jet method, where the Lorentz force of magnetic field jets out gaseous carbon particles to the JxB direction. In order to realize continuous mass production of these carbon clusters, the revolverinjection- type arc jet producer (RIT-AJP) has been developed. Production of fullerenes, endohedral metallo-fullerenes, SWNTs, metal-encapsulated carbon nano particles has been examined.

Lateral Load Resistance Of Laminated Veneer Lumber Sengonwooden Joints With Wooden Dowels, Niken Palaeowati, Ali Awaludin, Suprapto Siswosukarto

Makara Journal of Technology

Analytical models for wooden-doweled joints need to be developed. The objective of this research is to determine whether the strength of wooden-doweled joints can be well predicted by equations developed for steel-doweled joints. In this experiment, various connection parameters, such as dowel diameter, species of the wooden dowel, and angle of joints, are studied. The joint specimens are loaded in a quasi-static state with four replications each. A5% offset diameter method is used to determine the lateral load resistance of the tested joints, while the predictions are evaluated by equations given in Indonesian National Standard (SNI) 7973-2013 and the European …

Adjustable Resonance Frequency Of Rf-Mems Capacitor By Using Comb- Drive Actuators: A Design Approaches, Agus Santoso Tamsir, Sandy Tannu Wijaya, Dato’ Burhanuddin Yeop Majlis

Makara Journal of Technology

The needs of smaller size RF varactor is a must today, and MEMS comes to be the potential one. In this paper we proposed an adjustable resonance RF-MEMS varactor by using comb-drive actuators placing in each side of the square movable plate. In our preliminary simulation, we found that the device can work properly but some constraints comes such as the dominancies of harmonic resonance frequencies that influences into the nominal capacitances. Therefore for the next step of development we have to find out the window of the structural dimension for a certain spans and a certain operating frequencies.

Make Or Buy Analysis Model Based On Tolerance Design To Minimize Manufacturing Cost And Quality Loss, Cucuk Nur Rosyidi, Reza Rizkichani Akbar, Wakhid Ahmad Jauhari

Makara Journal of Technology

In a manufacturing company, manufacturing costs, or component prices, and tolerance will affect the price and the quality of a product. Companies must produce high-quality products with low manufacturing costs in order to keep their products competitive in the market; however, it is difficult to produce a high-quality product with a low manufacturing cost. Companies have difficulties in determining the components to be produced using their own manufacturing facilities (make) or outsourced to their suppliers (buy). Hence, a make or buy analysis is needed to minimize the manufacturing costs and quality loss and to determine the optimum alternative regarding make …

Observation Of Tunneling Effects In Lateral Nanowire Pn Junctions, Sri Purwiyanti, Arief Udhiarto, Daniel Moraru, Takeshi Mizuno, Djoko Hartanto, Michiharu Tabe

Makara Journal of Technology

As electronic device dimensions are continuously reduced, applied bias conditions significantly change and the transport mechanisms must be reconsidered. Tunneling devices are promising for scaled-down electronics because of expected high-speed operation and relatively low bias. In this work, we investigated the tunneling features in silicon-oninsulator lateral nanowire pn junction and pin junction devices. By controlling the substrate voltage, tunneling features can be observed in the electrical characteristics. We found that the minimum substrate voltage required for tunneling to occur in pn junctions is higher as compared with pin junctions. The main cause of these effects relies in the difference between …

Argon Ion Irradiation Effect On The Magnetic Properties Of Fe-Al2o3 Nano Granular Film, Setyo Purwanto, Isao Sakamoto

Makara Journal of Technology

We studied the effect of Argon (Ar) ion irradiation on Fe-Al2O3 nanogranular thin film. X-ray diffraction (XRD) patterns show that the ion dose might promote the growth of the Fe2O3 phase from an amorphous phase to a crystalline phase. The magnetic and magnetoresistance properties were investigated using a vibrating sample magnetometer (VSM) and a four point probe (FPP). The results suggest that percolation concentration occurred at the 0.55 Fe volume fraction and with a maximum magnetoresistance (MR) ratio of 3%. The present MR ratio was lower than that of previous results, which might be related to the existence of the …

Digestibility Of Betung Bamboo Fiber Following Fungal Pretreatment, Widya Fatriasari, Wasrin Syafii, Nyoman J. Wistara, Khaswar Syamsu, Bambang Prasetya

Makara Journal of Technology

This research evaluated the effect of fungal pretreatment of betung bamboo fibers and enzymatic- and microwaveassisted hydrolysis on the reducing sugar yield. The enzymatic hydrolysis of the pretreated biomass was carried out with cellulase and 10 and 20 FPU/g of substrate in a shaking incubator at 50 °C and 150 rpm for 48 h. The sulfuric acid concentration used in the microwave-assisted acid hydrolysis was 1.0, 2.5, and 5%, either with or without the addition of activated carbon. Microwave irradiation (330 Watt) was applied for 5–12.5 min. The yield of reducing sugar was better with the microwave-assisted acid hydrolysis, and …

Electron Emission Characteristics Of Multi-Gated Field Emitters, Hidenori Mimura, Yoichiro Neo, Toru Aoki, Tomoya Yoshida, Masayoshi Nagao

Makara Journal of Technology

We have developed a multi-gated field emitter (FE) such as a quadruple-gated FE with a three-stacked electrode lens and a quintuple-gated FE with a four-stacked electrode lens. Both the FEs can focus the electron beam. However, the quintuple-gated FE has a stronger electron convergence than the quadruple-gated FE, and a beam crossover is clearly observed for the quintuple-gated FE.

Properties Of Lignin From Oil Palm Empty Fruit Bunch And Its Application For Plywood Adhesive, Lucky Risanto, Euis Hermiati, Yanni Sudiyani

Makara Journal of Technology

Lignin from lignocellulosic biomass is a potential biopolymer for wood adhesive. The aims of this study were to characterize lignin isolated from the black liquor of oil palm empty fruit bunch fiber pretreated with steam explosion in alkaline conditions and to examine the bond quality of aqueous polymer isocyanate (API) adhesive prepared from lignin, natural rubber latex (NRL), and polyvinyl alcohol (PVA) as base polymers with isocyanate crosslinkers. Lignin was precipitated from the black liquor by adding hydrochloric acid; then the precipitate was separated by filtration, thoroughly washed with water up to pH 2 and pH 5, and dried. The …

The Gaussian Orthogonal Laplacianfaces Modelling In Feature Space For Facial Image Recognition, Arif Muntasa

Makara Journal of Technology

Dimensionality reduction based on appearance has been interesting issue on the face image research fields. Eigenface and Fisherface are linear techniques based on full spectral features, for both Eigenface and Fisherface produce global manifold structure. Inability of them in yielding local manifold structure have been solved by Laplacianfaces and further improved by Orthogonal Laplacianfaces, so it can yield orthogonal feature vectors. However, they have also a weakness, when training set samples have non-linear distribution. To overcome this weakness, feature extraction through data mapping from input to feature space using Gaussian kernel function is proposed. To avoid singularity, the Eigenface decomposition …

Series-Interconnected Plastic Dye-Sensitized Solar Cells Prepared By Low- Temperature Binder-Free Titania Paste, Erlyta Septa Rosa, Lia Muliani, Shobih Shobih, Jojo Hidayat, Brian Yuliarto

Makara Journal of Technology

The aim of this research is to study dye-sensitized solar cells (DSSC). This was implemented on a flexible polyethylene terephthalate (PET) substrate using a mixture of transparent and scattered mesoporous anatase-titania as the electron transport layer for the photoelectrode. This mixture of anatase titania performed a dual function of light scattering and efficient dye absorption. In this study, a porous nano-TiO2 film was prepared on indium tin oxide (ITO) coated polyethylene terephthalate (PET) by using a binder-free titania paste; on it, a DSSC was fabricated. The paste which contained a mixture of TiO2 nanoparticles, acid chloride, and ethanol was printed …