Metallurgy Commons^™

Influence Of Grain Size And Texture On Hall-Petch Relationship For A Magnesium Alloy, W. Yuan, S. K. Panigrahi, J. Q. Su, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

Friction stir processing was applied to a magnesium alloy to generate various grain sizes with the same intense basal texture. Subsequent tensile deformation along two orthogonal directions by easy activation or inhibition of basal slip follows the Hall-Petch relationship between yield stress and grain size in both directions. the Hall-Petch parameters are texture dependent. Easy activation of basal slip introduces lower values, while inhibition of basal slip leads to higher values. the Hall-Petch parameters are interpreted by texture and microstructural factors. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Grain Boundary Behavior In An Ultrafine-Grained Aluminum Alloy, P. S. De, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

The low-angle grain boundary (LAGB) stability in an ultrafine-grained (UFG) Al alloy during monotonic loading was investigated by orientation imaging microscopy (OIM). the experiments show that boundaries with misorientation below ∼2.5 deg are stable, while boundaries with misorientation between 2.5 and 15 deg are unstable. Similar results were observed during cyclic loading of UFG Al alloy. This behavior was rationalized using the nonequilibrium thermodynamics concept. on the other hand, it is postulated that the grain boundary behavior in microcrystalline alloy is different because of the larger dislocation mean free path. © 2011 the Minerals, Metals & Materials Society and ASM …

Spark Plasma Sintering Of Tungsten And Tungsten-Ceria: Microstructures And Kinetics, Jeffrey Bryce Perkins

Boise State University Theses and Dissertations

Tungsten casting is impractical, and tungsten compacts are most often produced by press-and-sinter or by hot pressing. The temperatures typically required to sinter tungsten above 90% dense are above 1800 ºC, and sintering times are typically hours. Alternatively, spark plasma sintering (SPS) can be used to consolidate materials to high densities at lower temperatures and shorter times than traditional sintering techniques. In this study, pure tungsten and tungsten with 1, 4, 10, 15, and 20 weight percent ceria were spark plasma sintered at varying pressures, temperatures, and times to investigate the microstructures and the kinetics of sintering.

Densification of tungsten …

Modeling And Control Of A Flexible Ionic Polymer Metal Composite(Ipmc) Actuator For Underwater Propulsion, Shivakanth Gutta

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this research is to model and control the underwater vehicle propelled by IPMC actuator. IPMC consists of an ionic membrane sandwiched between two metallic electrodes. When an external voltage is applied, IPMC undergoes large deformation due to transport of ions. Due to its ability to work in aqueous environments, it can be used for developing small scale underwater vehicles.

First, Finite element approach is used to describe the dynamics of the both single and segmented IPMC actuator. In the approach presented, each element is attached with a local coordinate system that undergoes rigid body motion along with …

Flexible Connection Elastomeric Rubber As A Pounding Resisting Element Between Two Adjacent Buildings, Yuskar Lase, James Jatmiko Oetomo

Makara Journal of Technology

Flexible Connection Elastomeric Rubber as a Pounding Resisting Element between Two Adjacent Buildings To solve pounding problem of two adjacent buildings, structural designer usually employs a dilatation between the structures or make the two structures as a monolith structure. Other alternative is by using an elastomeric rubber as a pounding resisting element between the two structures. Effectiveness in applying elastomeric rubber component as flexible connection of two adjacent structures is the main focus of this paper. Various simulations such as structure models, earthquake excitations and openings in gap element are studied. Observation of maximum structural responses will be performed for …

Improvement Of High Temperature Oxidation Of Low Carbon Steel Exposed To Ethanol Combustion Product At 700 °C By Hot-Dip Aluminizing Coating, Mohammad Badaruddin

Makara Journal of Technology

Low carbon steel (AISI 1005) was coated by hot-dipping into a molten Al-10% Si bath at 700 °C for 18s. After hotdipping treatment, the coating layers consisted of Al, Si, FeAl3, τ5-Fe2Al8Si, and Fe2Al5. The bare steel and the aluminized steel were isothermally oxidized at 700 °C in ethanol combustion product at atmospheric pressure for 49 h. The aluminized steel shows good performance in high temperature oxidation because the formation of Al2O3 layer on the coating surface. The growth of iron oxide nodules on the surface coating was accelerated by rapid outward diffusion of Fe-ions due to the presence of …

Effect Of Copper Addition On Mechanical Properties And Electrical Conductivity Of Pp/C-Cu Bipolar Plate Composites, Anne Zulfia, Taufik Abimanyu, Verina Warga Dalam

Makara Journal of Technology

Effect of Copper Addition on Mechanical Properties and Electrical Conductivity of PP/C-Cu Bipolar Plate Composites. Bipolar plate is a major component in PEM fuel cell which possess main function of collecting and removing electrons from anode to cathode. Therefore, materials for bipolar plates produced must have high electrical conductivity. To obtain bipolar plate materials which is cheap, lightweight and high conductivity, so it is developed bipolar plates material based on PP/C-Cu composite. PP/C-Cu composites has been made by mixing all materials then compounding, rheomix, hot blending and hot press. Cu (Copper) has been used various from 0.1 wt%, 1 wt% …

Application Of Principal Component Proximity Transform And Geostatistics Methods For Volume Shale Distribution As Reservoir Characreristic Imaging In Seismic 3d, Nur Islami

Makara Journal of Technology

Application of Principal Component Proximity Transform and Geostatistics Methods for Volume Shale Distribution as Reservoir Characreristic Imaging in Seismic 3D. Principal component proximity transform (PCPT) technique was used to predict the content of volume shale into seismic data in reservoir modeling framework. The goal in this research is to get the volume shale imaging in three dimensions and allow for reservoir modelling. The reservoir modelling requires an integrated quantitative and qualitative data sources collected separately, such as well and seismic data. Integrating PCPT and Geostatistic methods can generate the detail information for characterization of reservoir’s properties. Finally, it shows that …

Application Of Empirical Orthogonal Function Models To Analyze Shoreline Change At Bangkalan Madura, Darius Arkwright, Suntoyo Suntoyo

Makara Journal of Technology

Bangkalan’s shoreline, especially on the opposite side of Surabaya, has been evaluated to determine the morphological changes due to wave attack, near-shore current, long-shore sediment transport and coastal configuration. This research aims to determine the dominant patterns of variation of Bangkalan’s shoreline change, expressed by Eigen-function in empirical orthogonal function (EOF) models. That was started with data collection such as oceanographic data (wave and tidal), bathymetry and topographic map and sediment data. All data was used for forecasting two-monthly shoreline. Coordinate of two-monthly shoreline was used as input of EOF model. The first Eigen mode is a profile of shoreline …

Establishment Code Hand Palm (Palm Code) 2d Gabor-Based Method, I Ketut Gede Darma Putra, Wira Bhuana, Erdiawan Erdiawan

Makara Journal of Technology

Establishment Code Hand Palm (Palm Code) 2D Gabor-Based Method. Palmprint is relatively new in physiological biometrics. Palmprint ROI segmentation and feature extraction are two important issues in palm print recognition. This paper introduces two steps in the center of mass moment method for ROI segmentation that will be applied in the Gabor 2D filter to obtain palm code as palmprint feature vector. Normalized Hamming distance was used to measure the similarity degrees of two feature vectors of palmprint. The system was tested using database 1000 palmprint images generated from 5 samples from each of the 200 persons randomly selected with …

The Effectiveness Of Anaerobic Baffled Reactor And Rotating Biological Contactor In Batik Wastewater Treatment, Augustinus Ignatius Kristijanto, Widhi Handayani, Purwanti Asih Anna Levi

Makara Journal of Technology

Batik is one of popular arts of Indonesia. The batik industries in Sragen, Central Java, are prepared to compete in global market. In order to realize that objective, batik products should fulfill some qualifications, one of which is “environmental friendliness”. As batik production is usually generating wastewater which pollutes the environment, the technology of wastewater treatment should be developed to solve the problem. This preliminary study has been done to assess the effectiveness of anaerobic baffled reactor (ABR) and rotating biological contactor (RBC) in batik wastewater treatment. In 40 days of treatment period, the ABR performance in reducing pollutants showed …

Physical Characterization And Desulfurization Of Biobriquette Using Calcium-Based Adsorbent, Mahidin Mahidin, Asri Gani, Khairil Khairil

Makara Journal of Technology

Combustion of coal and co-combustion of their co-fuel contribute to gas emissions. Among the gas emissions are SOx, NOx, CO and CO2. Introduction of calcium based adsorbent is addressed to absorb SO2 that release to the atmosphere during the combustion process. Objective of the research is at first to observe the physical characteristics of biobriquettes as a function of briquette compositions (coal to palm kernel shell ratios) and Ca/S ratios (Ca in adsorbent and S in briquette) using a natural adsorbent (shellfish waste). The second objective is to investigate desulfurization characteristics as a function of Ca/S ratios and desulfurization temperatures …

Flutter Analysis Of Rx-420 Balistic Rocket Fin Involving Rigid Body Modes Of Rocket Structures, Novi Andria

Makara Journal of Technology

Flutter Analysis of RX-420 Balistic Rocket Fin Involving Rigid Body Modes of Rocket Structures. Flutter is a phenomenon that has brought a catastrophic failure to the flight vehicle structure. In this experiment, flutter was analyzed for its symmetric and antisymmetric configuration to understand the effect of rocket rigid modes to the fin flutter characteristic. This research was also expected to find out the safety level of RX-420 structure design. The analysis was performed using half rocket model. Fin structure used in this research was a fin which has semispan 600 mm, thickness 12 mm, chord root 700 mm, chord tip …

Analytical And Computational Simulation Approaches To Design Low Energy Glass Block, Floriberta Binarti, Agustinus Djoko Istiadji, Prasasto Satwiko, Priyo Tri Iswanto

Makara Journal of Technology

Analytical and Computational Simulation Approaches to Design Low Energy Glass Block. An environmentally friendly process was developed to produce a low embodied energy glass block from waste glasses. The energy efficiency of the glass block is represented by its thermal conductance (U)

Medium Density Fibreboard Made Of Acetylated Sludge From Paper Mill, Luthfi Hakim, Evalina Herawati, I Nyoman Jaya Wistara

Makara Journal of Technology

Medium Density Fibreboard Made of Acetylated Sludge from Paper Mill. Research of using sludge as raw material for making medium density fibreboard (MDF) was useful to create additional value of sludge. The objective of the research was to evaluate physical properties, mechanical properties, and durability of MDF from acetylated sludge in 4 levels of acetate anhydride (0%, 3%, 5%, and 7%) with 3 replicates. The MDF was made using dry process. After materials were mixed with adhesives, they were pressed using hotpress under 170 oC temperature and 45 Pa pressure for 25 minutes. The size of the MDF sample was …

Optimation Of Nitrogen And Phosphorus In Azolla Growth As Biofertilizer, Hany Handajani

Makara Journal of Technology

Nitrogen is one of the most important minerals for living organisms. Azolla is known as a small water fern which can fix nitrogen through the symbiotic association with the blue green algae Anabaena. Experimental studies were carried out in the glass house, investigating the growth of Azolla using different levels of nitrogen and phosphorus in the media. The experiment used 12 treatments with 3 levels of nitrogen (0, 5, and 10 mg atom/L) and 4 levels of phosphorus (0, 10, 20, and 30 mg atom/l) in a factorial design with 3 replicates. The results show that the highest biomass for …

Antibacterial Activity Of Papaya Leaf Extracts Against Pathogenic Bacteria, Elisa Friska Romasi, Jessica Karina, Adolf Jan Nexson Parhusip

Makara Journal of Technology

It was reported that the extracts of papaya leaves could inhibit the growth of Rhizopus stolonifer. Antibacterial activity of Carica papaya leaf extracts on pathogenic bacteria was observed in this study. Papaya leaves were extracted by using maceration method and three kinds of solvents: ethanol, ethyl acetate, and hexane. Papaya leaf extracts were tested against Bacillus stearothermophilus, Listeria monocytogenes, Pseudomonas sp., and Escherichia coli by agar diffusion method. The objectives of this study were to determine extract ability against pathogenic bacteria, to observe the influence of pH, NaCl, and heat on extracts ability, and to observe extract ability against B. …

Cassava Pulp As A Biofuel Feedstock Of An Enzymatic Hydrolysis Proces, Djuma’Ali Djuma’Ali, Nonot Soewarno, Sumarno Sumarno, Dyah Primarini, Wahono Sumaryono

Makara Journal of Technology

Cassava pulp, a low cost solid byproduct of cassava starch industry, has been proposed as a high potential ethanolic fermentation substrate due to its high residual starch level, low ash content and small particle size of the lignocellulosic fibers. As the economic feasibility depends on complete degradation of the polysaccharides to fermentable glucose, the comparative hydrolytic potential of cassava pulp by six commercial enzymes were studied. Raw cassava pulp (12% w/v, particle sizeμm) hydrolyzed by both commercial pectinolytic (1) and amylolytic (2) enzymes cocktail, yielded 70.06% DE. Hydrothermal treatment of cassava pulp enhanced its susceptibility to enzymatic cleavageas compared to …

Alos/Palsar Image Processing Using Dinsar And Log Ratio For Flood Early Detection In Jakarta Based On Land Subsidences, Dodi Sudiana, Mia Rizkinia

Makara Journal of Technology

Flood that occurred in Jakarta is not only influenced by rainfall, urban planning system and drainage alone, but also may be involved land subsidence (LS). LS is possible in because Jakarta stands on top of layers of sediments and the presence of ground water consumption in very large quantities. In this research, the Advanced Land Observing Satellite (ALOS)/Phased Array type L-band Synthetic Aperture Radar (PALSAR) data was processed to determine the level of LS in Jakarta area and its relation to flood potential area. Differential interferometry method (DInSAR) was performed on two PALSAR data with different acquisition years, i.e. 2007 …

Fabrication Of Size-Tunable Metallic Nanoparticles Using Plasmid Dna As A Biomolecular Reactor, Jacopo Samson, Irene Piscopo, Alex Yampolski, Patrick Nahirney, Andrea Parpas, Amit Aggarwal, Raihan Saleh, Charles Michael Drain

Publications and Research

Plasmid DNA can be used as a template to yield gold, palladium, silver, and chromium nanoparticles of different sizes based on variations in incubation time at 70 °C with gold phosphine complexes, with the acetates of silver or palladium, or chromium acetylacetonate. The employment of mild synthetic conditions, minimal procedural steps, and aqueous solvents makes this method environmentally greener and ensures general feasibility. The use of plasmids exploits the capabilities of the biotechnology industry as a source of nanoreactor materials.

A Quantitative Study Of The Weldability Of Inconel 718 Using Gleeble And Varestraint Test Methods, Sean Quigley

Master's Theses

Nickel super alloy Inconel 718 was tested and compared to Haynes 230 using Gleeble and Varestraint mechanical test methods. Hot cracking susceptibility was examined in either alloy using a sub-scale Varestraint test method at 5 augmented strain levels: 0.25%, 05.%, 1%, 2%, and 4%. Maximum crack length, total crack length, and number of cracks were measured for each strain level. Gleeble hot ductility on-heating and on-cooling tests were performed on both alloys. Inconel 718 was tested on-heating at target temperatures of 1600˚F, 2000˚F, 2100˚F, 2200˚F, and on cooling at 1600˚F, 1700˚F, 1800˚F, 1900˚F, and 2100˚F. Haynes 230 was tested on-heating …

Design, Fabrication, And Characterization Of A Thin-Film Nickel-Titanium Shape Memory Alloy Diaphragm For Use In Micro-Electro-Mechanical Systems, Brian Joel Alvarez

Master's Theses

Previous work done at Cal Poly has shown that thin-film nickel-titanium (NiTi) can be easily sputtered onto silicon wafers and annealed to create a crystallized shape memory alloy (SMA) film. Initial work on creating devices yielded cantilevers that were highly warped due to thin-film stress created during the sputtering process. The objective of this work was to create a thin-film NiTi SMA device that could be better characterized. A membrane was selected due to the simplicity of fabrication and testing which would also oppose the thin-film stress due to the increase in attachment points to the substrate.

Silicon wafers were …

Effect Of Au Content On Microstructural Evolution Of Snagcu Solder Joints That Undergo Isothermal Aging And Reliability Testing, Patrick J. Hyland

Master's Theses

Electronics, especially, printed circuit boards (PCBs) are a widespread technology. Metal coatings or “surface finishes” are often added to PCB board pads and component leads during manufacturing to improve their performance. Electroplated nickel/gold over copper is a popular surface finish for printed circuit boards and component leads. The presence of gold in solder joints, however, is known to have detrimental effects referred to as gold embrittlement. It is generally understood that tin-lead solder joints with less than 3 weight percent (wt%) of gold will not experience reliability issues. The acceptable level of gold in lead-free solder joints, however, is less …

Time-Dependent Crack Growth Behavior Of Alloy 617 And Alloy 230 At Elevated Temperatures, Shawoon Kumar Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two Ni-base solid-solution-strengthened superalloys: INCONEL 617 and HAYNES 230 were studied to check sustained loading crack growth (SLCG) behavior at elevated temperatures appropriate for Next Generation Nuclear Plant (NGNP) applictaions with constant stress intensity factor (K _max = 27.75 MPa[checkmark]m) in air. The results indicate a time-dependent rate controlling process which can be characterized by a linear elastic fracture mechanics (LEFM) parameter - stress intensity factor (K). At elevated temperatures, the crack growth mechanism was best described using a damage zone concept. Based on results and study, SAGBOE (stress accelerated grain boundary oxidation embrittlement) is considered the primary reason for …

Mapping Mos2-Co Catalytic Nanostructures Using Hrtem And Tem Simulations, Eduan Martínez-Soto ^, Brenda Torres, Domingo Ferrer, Gilles Berhault, Russell Chianelli, Manuel Ramos *

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Process Refinement Through Design Of Experiments (Taguchi) To Reduce Porosity Levels Of Thin Flame Spray Nicrbsi Coatings On Cast Aluminium Alloys, David Culliton, David Kennedy, Tony Betts

Conference Papers

Thin(16matrix of key deposition parameters was constructed to develop the optimum spray parameters. The effects of parameter variations on the porosity levels of these coatings were assessed. Key parameter interactions were reported. Quantifiable interactions between the selected parameters were noted for the LM24 substrate. However, on the LM25 substrate these interactions were much less defined. Corrosion performance of the optimised coatings, based on electrochemical impedance spectroscopy, was reported. The presence of through-pores in the coatings were shown to reduce the corrosion resistance of the coated systems by a factor of 10, in dilute NaCl solutions, compared to bulk 316L stainless …

Dissimilar Metal Weld Variability Due To Lot Differences In Nitinol/ Stainless Steel Interface, Matthew R. Rudow

Materials Engineering

Abstract

An experiment was conducted to determine and reduce the causes of variation between a 304 Stainless Steel and super elastic Nickel Titanium dissimilar metal weld. Six factors were established to understand the cause of variation: perpendicularity, final grind, surface finish, weld force, weld pulse duration, and alignment. Using a rotational test with an air piston break pressures were established and charted in Minitab to identify trends. It was shown that weld force and weld pulse duration were the two factors that had the most influence on break strength. This data also showed that higher strength groups had less variability. …

The Effects Of Heat Treatment On Area Percent Porosity And Corrosion Behavior Of High-Nickel Thermal Spray Coatings, Travis Crowe, Alec Guraydin

Materials Engineering

Samples of two Thermal Spray Coating (TSC) alloys on a low carbon steel substrate were obtained: alloy C276 and Nicko-Shield 200. Specimens of each alloy were subjected to heat treatments at temperatures at 1100° for 60 minutes and 1200° for 10 minutes, with some specimens left in the as-sprayed condition. Three replicates were prepared for each condition. Thin 1” strips were cut using a diamond wafering blade for porosity measurements and 2” x 1” specimens were cut for corrosion testing using a SiC abrasive saw. The porosity specimens were mounted in acrylic resin, polished, and examined using SEM. From these …

Characterization Of The Relationship Between The Microstructure And Tensile Strength Of Annealed Ti-6al-4v, Aldo Corona

Materials Engineering

Tensile coupons of Ti-6Al-4V were heat treated at varying annealing temperatures from 1200°F (648°C) to 1450°F (787°C)  at 50°F  (23°C) increments for 1 hour. The samples were air cooled to room temperature or furnace cooled to 800°F (426°C) followed by air cooling to room temperature. Four tensile coupons were treated at each annealing temperature and cooling rate. Alpha case was observed to form on the surface of the samples post heat treatment with a maximum depth of 25 µm (.001 in). Samples were tensile tested for their ultimate tensile strength, yield strength, and percent elongation.  Samples across all annealing temperatures …

Review Of The Maxus 8 Sounding Rocket Experiment To Investigate Solidification In A Ti-Al-Nb Alloy, Robin Mooney, David Browne, Olga Budenkova, Yves R. Fautrelle, Ludo Froyen, Andrey Kartavykh, Stephan Rex, Burkhard Schmitz, Daniella Voss, Shaun Mcfadden

Conference Papers

A review of the MAXUS 8 sounding rocket microgravity experiment to investigate solidification structures in a Ti-Al-Nb intermetallic alloy is presented. The experiment was part of the Intermetallic Materials Processing in Relation to Earth and Space Solidification (IMPRESS) EU FP6 project. Key objectives were to investigate columnar and equiaxed solidification, and to achieve Columnar-to-Equiaxed Transition (CET) in the alloy. A microgravity experiment was designed to achieve this using a controlled power-down method. Two alloys were tested: one inoculated with a grain refiner and the other without grain refinement. Unrefined samples displayed axial and radial columnar growth. Boride inoculated samples displayed …