Metallurgy Commons^™

Optimization Of Electricity Generation Schemes In The Java-Bali Grid System With Co2 Reduction Consideration, Farizal Farizal, Wenty Eka Septia, Amar Rachman, Nasruddin Nasruddin, Teuku Meurah Indra Mahlia

Makara Journal of Technology

This research considers the problem of reducing CO2 emissions from the Java-Bali power grid system that consists of a variety of power-generating plants: coal-fired, natural gas, oil, and renewable energy (PV, geothermal, hydroelectric, wind, and landfill gas). The problem is formulated as linear programming and solved using LINGO 10. The model was developed for a nation to meet a specified CO2 emission target. Two carbon dioxide mitigation options are considered in this study, i.e. fuel balancing and fuel switching. In order to reduce the CO2 emissions by 26% in 2021, State Electric Supply Company (PLN) has to generate up to …

The Knowledge-Based Analysis On Medium Resolution Images Of Remote Sensing To Extraction Information Land Use Type Scs-Cn, The Case Study On Grompol Watershed, Puguh Dwi Raharjo, Totok Gunawan, Mohammad Pramono Hadi

Makara Journal of Technology

Remote sensing imagery Landsat-8 is one image that has a good temporal resolution; in addition to the availability of data, this image can be obtained free of charge. Land cover type SCS-CN is part of a unit of land that affects runoff. The use of medium resolution imagery in reducing the SCS-CN land use type is considered relatively difficult, and it yields less good accuracy. Limitations on multispectral classification only rely on facts derived from spectral reflection, so that the two data are the same since different characteristic results are not so good. This study aims to determine the accuracy …

The Effect Of Irradiation Of Fe And Ar Ion On The Surface Morphology Of Diamond Thin Film Related To The Magnetoresistance Property, Salim Mustofa, Setyo Purwanto, Kenji Mishima

Makara Journal of Technology

The irradiation of Fe and Ar ion was applied on the surface of diamond/Si thin film to know its effect on the morphology of thin film.The magnetoresistance property was also studied. Ion irradiation treatment using Fe ion followed by argon ion at the energy of 70keV and a dose of 1 x 1015 ion/cm2 have been conducted on the surface of two types of thin film, diamond/Si (111) and diamond/Si (100). Both thin films were made by using a CVD method, and the thickness of the thin film is 1000-nm. From simulations using the software called Stopping and Range of …

Use Of Green Mussel Shell As A Desulfurizer In The Blending Of Low Rank Coal-Biomass Briquette Combustion, Mahidin Mahidin, Asri Gani, M. Reza Hani, Muhammad Syukur, Hamdani Hamdani, Khairil Khairil, Samsul Rizal, Abdul Hadi, T.M.I. Mahlia

Makara Journal of Technology

Calcium oxide-based material is available abundantly and naturally. A potential resource of that material comes from marine mollusk shell such as clams, scallops, mussels, oysters, winkles and nerites. The CaO-based material has exhibited a good performance as the desulfurizer or adsorbent in coal combustion in order to reduce SO2 emission. In this study, pulverized green mussel shell, without calcination, was utilized as the desulfurizer in the briquette produced from a mixture of low rank coal and palm kernel shell (PKS), also known as bio-briquette. The ratio of coal to PKS in the briquette was 90:10 (wt/wt). The influence of green …

Apparent Porosity And Compressive Strength Of Heat-Treated Clay/Iron Sand/Rice Husk Ash Composites Over A Range Of Sintering Temperatures, M. Nizar Machmud, Zulkarnain Jalil, Mochammad Afifuddin

Makara Journal of Technology

Novel composites of clay/iron sand/rice husk ash (RHA) have been developed. Electric furnace was used to perform heat treatment on the composites to study the effect of sintering temperature on their apparent porosity and compressive strength. Two types of RHA with different bulk density were prepared to gain an understanding of the influence of apparent porosity on compressive strength of the heat-treated composites over a range of sintering temperatures. Heattreated composites, made of clay/iron sand and clay/RHA, were also prepared as a referenced material. X-ray diffraction (XRD) analysis was further performed to comprehensively discuss the role of iron sand on …

Thermoelectric Half-Heuslers: Synthesis, Processing, And Performance, Joseph Robert Croteau

Boise State University Theses and Dissertations

Thermoelectric half-Heusler compounds have potential to convert the heat wasted from industrial and transportation processes to useful electricity. Among the highest performing half-Heusler compounds are nano-structured bulk materials which have been arc-melted, pulverized into a nano-powder, and sintered by DC-hot press. High performing n- and p-type half-Heusler compounds with nominal composition of Hf_0.25Zr_0.75NiSn_0.99Sb_0.01 and Nb_0.75Ti_0.25FeSb, respectively, have been provided to us in both dense and powder form by our collaborators at the University of Houston. We consolidate these powders by SPS, refine these powders to improve both particle size …

Photoluminescence Measurement On Low-Temperature Metal Modulation Epitaxy Grown Gan, Yang Wu

Graduate Theses and Dissertations

A low-temperature photoluminescence (PL) study was conducted on low-temperature metal modulation epitaxy (MME) grown GaN. By comparing the PL signal from high temperature grown GaN buffer layers, and MME grown cap layers on top of the buffer layers, it was found that MME grown GaN cap has a significantly greater defect-related emission. The band edge PL from MME grown GaN found to be 3.51eV at low temperature. The binding energy of the exciton in GaN is determined to be 21meV through temperature dependence analysis. A PL peak at 3.29eV was found in the luminescence of the MME grown cap layer, …

Cermet Development For High Temperature And High Pressure Applications, Beatriz Justus Ferez, Samantha Guthrie, Brian J. Jaques (Mentor), Darryl P. Butt (Mentor)

Idaho Conference on Undergraduate Research

Many traditionally used low cost alloys are easily corroded in steam or supercritical CO₂. An effective solution is to utilize ceramic heat exchangers that are often integrated with metallic components which result in a significant thermal expansion mismatch. The goal of this project is to develop a sealing method to create a hermetic joint between the ceramic and metal alloy. Proposed is a seal ring containing a cermet powder with a coefficient of thermal expansion (CTE) higher than the ceramic and metal to produce a high temperature compressive seal. Cermets of Ag and MgO have been selected to …

Comparison Study Of Tensile Strength , Ductility, And Fracture Mode Of H11, Arp 2000, And Mp35n Connecting Rod Bolts For Use In High Performance Racing Engines, Megan Mccabe, Samuel Randall

Materials Engineering

Oliver Racing Parts (ORP) has historically purchased connecting rod bolts made of high strength, high cost, nickel-cobalt alloy, MP35N, and a medium strength, low cost, proprietary tool steel called ARP 2000. ORP has recently acquired capabilities to manufacture their own bolts. To determine the quality of their product as it compares to their previous supplier, ORP produced three different types of ⅜” diameter bolts: one set of bolts made of MP35N, and two sets of H11 bolts, designated H11A and H11B for their respective processing. The H11, ARP 2000, and MP35N bolts were tensile tested using a custom designed test …

Superalloy Metallurgy A Gleeble Study Of Environmental Fracture In Inconel 601, Alan C. Demmons

Master's Theses

At temperatures above 0.5 Tm and in aggressive atmospheres predicting alloy performance is particularly challenging. Nickel alloys used in regimes where microstructure and properties are altered dynamically present unique requirements. Exposure may alter properties with unexpected early failure. The Gleeble is a valuable tool for investigation and simulation of thermo-mechanical properties of an alloy in various regimes up to the threshold of melting. In this study, four regimes of temperature and strain rate were simulated in an argon atmosphere to both investigate and document normal and abnormal failure modes. Commercial Inconel 601 was tested in selected regimes and in two …

Welding Procedure Qualification Of A36 Steel Plates Using The Gtaw And Gmaw Processes, Brecken Deoilers, Neri Lupian, Regan Rumph

Materials Engineering

The purpose of this project was to qualify welding procedure specifications for the Las Positas College welding program using A36 steel in accordance with American Welding Society (AWS) D1.1, B4.0, and B2.1. Qualification was to be performed using both 1G (flat) and 3G (vertical) positions for Gas Tungsten Arc Welding (GTAW) and Gas Metal Arc Welding (GMAW) processes. Required qualification procedures included two face and two root bend tests coupled with a visual inspection for cracks within the weld region greater than ⅛” long, along with two reduced section tensile tests to ensure the tensile strength exceeded 58 ksi if …

Effect Of Thermal Exposure On Tensile Strength And Microhardness Of Welded And Precipitation Hardened Rx82 Aluminum Alloy Extrusions In The T4 And T6 Conditions, Lucien Miller

Materials Engineering

This investigation is focused on the effect paint-bake cycles have on the tensile strength and microhardness of GMAW welded RX82 aluminum extrusions in T4 and T6 base conditions. To simulate the paint-bake cycle, T4 and T6 RX82 aluminum samples were GMAW welded and heat treated at 350°F, 390°F, and 425°F for durations of 30 minutes, 1.0 hour, and 2.0 hours, with five replicates for each treatment. Microhardness profiles of T4 samples treated at 350°F for 30 minutes and 1.0 hour display weld/HAZ HV values of 86.04 and 82.51 respectively, followed by maximums of 123.21 and 121.10. Average ultimate tensile strength …

Investigation Of Outlife Time On The Environmental Durability Of P2-Etched, Adhesively-Bonded Aluminum Alloys Using The Astm Wedge Test, Daniel Gross, Corey Sutton

Materials Engineering

P2 etchant is an environmentally-friendly aluminum etchant which has the potential to replace the Forest Products Laboratory (FPL) etchant as the industry standard. Environmental durability of adhesively-bonded aluminum surfaces etched using a paste version of the P2 etchant were tested using the Boeing-developed wedge test (ASTM D3762 - 03(2010)). This project specifically aimed to examine the relationship between outlife time (the time between etching and adhering) and the ability of bonded aluminum samples to pass the wedge test. Two aluminum alloys, 2024-T3 and 7075-T6, were wedge tested and the etched surfaces examined with an atomic force microscope (AFM) and a …

Effect Of Hydrogen Pick-Up And Release Behavior On The Tensile Properties Of Electroplated 4340m High-Strength Steel, Blake Daylor, Joshua Fisher, Alan Michelen Ruiz

Materials Engineering

Hydrogen embrittlement of high-strength steel (4340M) was quantified through tensile testing and fractography (SEM). Three types of samples were obtained: rotating beam fatigue specimens, round (notched) tensile specimens, and flat panel specimens. In addition, three different plating types were analyzed (Ni, Cr, Cd-Ti) with a set of samples that was shot peened and a set that was not. Since some of the samples went through a hydrogen relief bake, another factor in our experiment was the amount of time it took for the samples to reach the baking process after they were electroplated (bake delay). There were three levels of …

Controlling Grain Size In Cold Worked And Annealed 1100 Aluminum To Optimize Ductility In Rocket Diaphragm Systems, Ryan Lewis, Bryce Simmons, Jessica Williams

Materials Engineering

Liquid propellant rocket diaphragms require extreme ductility. 1100 Aluminum is used for its high ductility, but the post-processing cold work and subsequent anneal result in excessively large grains. The effect of heat treatment and cold work on grain size in 1100 aluminum was explored. The samples were cold worked to 0, 5, 10, 15 and 30% using tensile elongation. The samples were then heat treated per AMS 2770 with either a "Steel Conduction" (1000 – 1150°F/min) or a "Production" (16 – 18°F/min) heating rate. The grain size of the samples were measured using the mean lineal intercept method. The grain …

Metals Additive Manufacturing Powder Aging Characterization, Thomas Russell Lovejoy, Nicholas Karl Muetterties, David Takeo Otsu

Mechanical Engineering

The metallic additive manufacturing process known as selective laser melting requires highly spherical, normally distributed powder with diameters in the range of 10 to 50 microns. Previous observations have shown a degradation in powder quality over time, resulting in unwanted characteristics in the final printed parts. 21-6-9 stainless steel powder was used to fabricate test parts, with leftover powder recycled back into the machine. Powder samples and test specimens were characterized to observe changes across build cycles. Few changes were observed in the physical and mechanical properties of the specimens, however, there were indications of chemical changes across cycles. Potential …

Grain Orientation Effects On The Rotating-Bending Fatigue Properties Of Forged 7050-T7452 Aluminum Alloy, Matt Cristler, Jonas Zhang

Materials Engineering

In order to investigate the effects of grain orientation on the high cycle fatigue properties of 7050-T7452 aerospace grade aluminum, rotating-bending fatigue tests were performed on longitudinal (LG) and short transverse (ST) specimens taken from two sample sets (Method A and Method B) of open die forged 7050 aluminum. The fatigue specimens were machined to a 0.2" gage diameter and 4" length and subsequently hand polished to a mirror finish to minimize potential crack initiation sites. The tests were conducted on a Fatigue Dynamics RBF-300 HT tester in the fully reversed loading condition, with stress levels varying from 20 ksi …

Manipulation Of Surface Plasmon Resonance In Metal And Alloy Thin Films Using Dielectric Media, Benjamin Dubray Hall

Graduate Theses - Physics and Optical Engineering

Surface plasmon polaritons are coherent electron oscillations that propagate along an interface between a Drude metal and a dielectric medium. The excitation of polaritons is highly dependent on the dielectric properties of the metal, the thickness of the metal, and the optical properties of the dielectric material. First, plasmonic activity is assessed for several thicknesses of silver and nickel chromium under He-Ne incidence. Relationships between film thickness and metal dielectric function are explored in both cases. To manipulate the plasmonic activity at the silver surfaces, two methods are explored. Silver oxide was grown on the surface of the silver films, …

Coercivity Enhancement And Gamma Phase Avoidance Of Alnico Alloys, Li Zhang

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

The promotion of social progress requires greater levels of energy efficiency, quality and productivity. However, these developments usually come at the cost of the environment. Green technologies such as electric vehicles, wind turbine and solar panels are ironically overshadowed by supply limitations and high prices of rare earth elements. Therefore, it is important to find alternative materials to replace those that contain critical elements. Alnico alloys show high magnetization, high Curie temperature (800°C) and good corrosion resistance, making it one of the best candidates to replace neodymium-based magnets used in electric vehicles.

In this thesis, methods controlling shape anisotropy and …

Vacuum Brazing Of Diamond To Tungsten Carbide, Zhiyong Yin

Graduate Theses & Non-Theses

Diamond tools are increasingly gaining importance as cutting and drilling materials for a wide variety of industrial applications. Polycrystalline diamond (PCD) is the main ultrahard material commercially used in the oil and gas drilling industry. In this study, a reactive brazing process was developed to join polycrystalline diamond (PCD) to WC-13 wt% Co, to form the cutter for fixed-cutter drill bit applications.

Most nonmetals including polycrystalline diamond are not wet by and cannot easily be joined with conventional brazing alloys due to their chemical stability. The experimental approach was first to analyze the effect of adding an active metal (Ti, …