Metallurgy Commons^™

Material Properties Of Laser Powder Bed Fusion Processed 316l Stainless Steel, Steven Keckler

Graduate Theses & Non-Theses

Laser powder bed fusion additive manufactured 316L stainless steel specimens were evaluated to establish a baseline for future research in determining an optimized energy density and build orientation. Test specimens were printed at various energy densities. At each energy density, tensile and fatigue specimens were printed at 0o (longitudinal), 45o, and 90o (transverse) orientation to the build plate. Tensile and high cycle fatigue tests were performed then representative fracture surfaces were analyzed. The apparent melt track and dendrite size were evaluated using grain analysis software. Static loading of the tensile specimens showed a marginal difference in UTS for specimens with …

Modeling And Simulation Of Mass Flow Of Steel Plate/Slab During Hot Rolling, X. Wang, S. Ganguly, K. Chandrashekhara, Mario F. Buchely, Semen Naumovich Lekakh, David C. Van Aken, Ronald J. O'Malley, D. Bai, Y. Wang, T. Natarajan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ability to predict mass flow behavior during hot rolling is essential to product quality. In this study, viscoplastic models of the steels from SSAB and U.S. Steel were developed based on experimental stress-strain curves. A three-dimensional nonlinear finite element model was built to simulate a reverse plate hot rolling and a hot strip rolling process. For plate rolling, a seven pass schedule was simulated. The plastic strain distributions during rolling were investigated. The results show that the surface of the plate has larger plastic strain than the center. In the case of hot strip rolling, the simulation predicts that …

In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals, Jeremy Geovann Del Aguila

Materials Engineering

Scanning electron microscopy (SEM) video recording is used to characterize the solidification of small volumes of 99.999% pure gallium (Ga) and eutectic gallium-indium (eGaIn) under a high vacuum environment. Specimen are superheated to 55℃ using a hot plate, cast into spherical droplets, and cooled in situ by means of a Peltier cooling stage. Special attention is given to the preparation of the specimen prior to viewing because of gallium and its alloys’ nature to form an oxide layer when melted and air cooled. The oxide acts as a skin that inhibits the observation of microstructural features during solidification. Heated samples …

An Evaluation Of Ultrasonic Shot Peening And Abrasive Flow Machining As Surface Finishing Processes For Selective Laser Melted 316l, Rhys Gilmore

Master's Theses

Additive Manufacturing, and specifically powder bed fusion processes, have advanced rapidly in recent years. Selective Laser Melting in particular has been adopted in a variety of industries from biomedical to aerospace because of its capability to produce complex components with numerous alloys, including stainless steels, nickel superalloys, and titanium alloys. Post-processing is required to treat or solve metallurgical issues such as porosity, residual stresses, and surface roughness. Because of the geometric complexity of SLM produced parts, the reduction of surface roughness with conventional processing has proven especially challenging. In this Thesis, two processes, abrasive flow machining and ultrasonic shot peening, …

Temper Response Of A Vanadium Microalloy Steel, Bradley W. Hostetler

Materials Engineering

This investigation details the effect of a quench-and-temper processing treatment on the mechanical properties of a microalloy steel being considered for use as a pipeline flange. Microalloy steels are normally processed via Thermo-Mechanically Controlled Processing (TMCP) due to the increased strength from ferrite grain refinement; however, the geometry of a pipeline flange requires post processing beyond TMCP which diminishes the strengthening effect provided by TMCP. The purpose of this research project is to determine the mechanical properties produced when a vanadium microalloy steel is quenched and tempered. The two major considerations are the effect of tempering time on properties and …

Anomalous 304 Stainless Steel Mechanical Properties In Medical Guide Wires, Andrew Joseph Freeman

Materials Engineering

Stainless steel medical guide wire cores, processed by Abbott Vascular, are returning anomalous mechanical properties upon strain hardening and heat treatment. As theory dictates, mechanical strength properties increase with strain hardening, and decrease with an annealing treatment. The opposite response is being observed. This is counter intuitive to fundamental materials knowledge, and a perfect materials engineering paradox. This project was designed to characterize these behaviors, and attempt to determine causation. To accomplish this, tensile testing of all processing steps mapped the mechanical property evolution of the wire. Published literature research revealed the potential of nitrogen and chromium solid state diffusion …

The Effects Of Varying Composition And Build Direction On Direct Metal Deposition Fabricated Inconel 718, Abigail P. Nilan, Jessica M. Fordham

Materials Engineering

Inconel 718 (IN718) is a popular wrought superalloy, and is currently being investigated for additive manufacturing (AM) applications in the aerospace industry. However, overaging and the presence of microcracks have caused a significant reduction in properties. The purpose of this study is to meet or exceed the mechanical properties of wrought IN718 by varying the composition and build direction of the AM alloy. Alternative compositions were selected with Oerlilon Metco’s Rapid Alloy Development (RAD) software, and differ in niobium content, which increases the fraction of the primary strengthening phase (γʺ). Direct metal deposition (DMD) was used to fabricate the samples, …

Investigation Of Narloy-Z Yield Strength In Response To Changes In Ingot Processing And Heat Treatment, Stanley C. Goto, Sarah E. Wattenberg

Materials Engineering

This study investigates the effect of cooling rate on the yield strength of NARloy-Z. NARloy-Z is a copper-based alloy with 3 wt.% silver and 0.5 wt.% zirconium. The types of NARloy-Z were classified by the ingot processing (old or new) and the material lot (old or new). There were three variations of NARloy-Z in this study: old processing and material (Old/Old); old processing and new material (Old/New); and new processing and material (New/New). NARloy-Z undergoes a braze thermal cycle and age (BTCA) heat treatment for its application, and a single cooling rate within the BTCA was manipulated in this study. …

Effects Of Head Formation And Heat Treatment On The Mechanical Properties Of Connecting Rod Bolts, Caleb A. Leavitt, Matthew R. Lauretta

Materials Engineering

Oliver Racing Parts (ORP; Charlevoix, Michigan) is looking to optimize their manufacturing process for high-strength connecting rod bolts. A high yield strength is desired for the bolts because deformation would result in catastrophic engine failure. The bolts were made of H11, a chromium hot-work tool steel; and MLX17, a precipitation hardenable stainless steel. Tensile testing was performed to determine the tensile and yield strengths of the bolts. Fracture surfaces were imaged via scanning electron microscopy to characterize the failure modes. To observe the effects of bolt heading on microstructure and bolt strength, two batches of MLX17 were prepared; one batch …

Research And Development Of Powder Brazing Filler Metals For Diamond Tools: A Review, Fei Long, Peng He, Dusan P. Sekulic

Mechanical Engineering Faculty Publications

Powder brazing filler metals (PBFMs) feature a number of comparative advantages. Among others, these include a low energy consumption, an accurate dosage, a good brazeability, a short production time, and a high production efficiency. These filler metals have been used in the aerospace, automobile, and electric appliances industries. The PBFMs are especially suitable for diamond tools bonding, which involves complex workpiece shapes and requires accurate dosage. The recent research of PBFMs for diamond tools is reviewed in this paper. The current applications are discussed. The CuSnTi and Ni-Cr-based PBFMs have been the two commonly used monolayer PBFMs. Thus, the bonding …

Analysis Of Surface Integrity In Machining Of Aisi 304 Stainless Steel Under Various Cooling And Cutting Conditions, F. Klocke, B. Döbbeler, S. Lung, S. Seelbach, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Recent studies have shown that machining under specific cooling and cutting conditions can be used to induce a nanocrystalline surface layer in the workspiece. This layer has beneficial properties, such as improved fatigue strength, wear resistance and tribological behavior. In machining, a promising approach for achieving grain refinement in the surface layer is the application of cryogenic cooling. The aim is to use the last step of the machining operation to induce the desired surface quality to save time-consuming and expensive post machining surface treatments. The material used in this study was AISI 304 stainless steel. This austenitic steel suffers …

The Incorporation Of Graphene To Lithium Cobalt Oxide As A Cathode To Improve The Performance Of Lithium Ion Batteries, Kenan Wang

Graduate Theses and Dissertations

One of the objectives of this thesis work was to investigate the cathode performance of lithium cobalt oxide (LiCoO2) incorporated with graphene powder in lithium ion batteries (LIBs). Graphene powder was incorporated into cathode materials to enhance the performance of LIBs. The other objective was to impede the construction of a solid electrolyte interphase (SEI) sheet using graphene sheet coating on its cathode.

The results of this work show that adding graphene powder improved the performance of LiCoO¬2 as a cathode material. With the incorporation of different weight percentages of graphene powder, the LiBs showed distinct changes in their charging …

Ultrasonic Nondestructive Evaluation Of Metal Additive Manufacturing., Venkata Karthik Nadimpalli

Electronic Theses and Dissertations

Metal Additive Manufacturing (AM) is increasingly being used to make functional components. One of the barriers for AM components to become mainstream is the difficulty to certify them. AM components can have widely different properties based on process parameters. Improving an AM processes requires an understanding of process-structure-property correlations, which can be gathered in-situ and post-process through nondestructive and destructive methods. In this study, two metal AM processes were studied, the first is Ultrasonic Additive Manufacturing (UAM) and the second is Laser Powder Bed Fusion (L-PBF). The typical problems with UAM components are inter-layer and inter-track defects. To improve the …

Self-Assembled Barium Titanate Nanoscale Films By Molecular Beam Epitaxy, Timothy Allen Morgan

Graduate Theses and Dissertations

One challenge of investigating ferroelectrics at the nanoscale has been controlling the stoichiometry during growth. Historically, the growth of barium titanate (BaTiO3) by molecular beam epitaxy has relied on a growth technique called shuttered RHEED. Shuttered RHEED controls the stoichiometry of barium titanate through the precise deposition of alternating layers of BaO and TiO2. While this approach has achieved 1% control of stoichiometry, finding self-limiting mechanisms to lock-in stoichiometry has been the focus of the growth community. The Goldschmidt tolerance factor predicts an unstable perovskite when barium sits in the titanium lattice site. The BaO-TiO2 phase diagram predicts a low-solubility …

Fabrication And Characterization Of Graphene Based 2d Materials For Supercapacitors, Anishkumar Manoharan

Graduate Theses and Dissertations

Supercapacitors have attracted a lot attention due to their efficient energy storage. In comparison to batteries, supercapacitors have high capacitance, energy, and power densities per unit mass than conventional capacitors. Carbon based materials are most promising in supercapacitor application due to their outstanding physical and electrochemical behavior. In this work, a facile method to synthesize a nanocomposite electrode consisting of annealed carbon from carbon ink and MoS2 was demonstrated. Effects of various aqueous and solid electrolytes were studied. It was found that the nanocomposite electrode with 10% MoS2 and 1M Na2SO4 as the aqueous electrolyte tested using the three electrode …

Evolution Of Mg Az31 Twin Activation With Strain: A Machine Learning Study, Andrew D. Orme

Undergraduate Honors Theses

Machine learning is being adopted in various areas of materials science to both create predictive models and to uncover correlations which reveal underlying physics. However, these two aims are often at odds with each other since the resultant predictive models generally become so complex that they can essentially be described as a black box, making them difficult to understand. In this study, complex relationships between microstructure and twin formation in AZ31 magnesium are investigated as a function of increasing strain. Supervised machine learning is employed, in the form of J-48 decision trees. In one approach, strain is incorporated as an …

Characterization Of Process Induced Defects In Laser Powder Bed Fusion Processed Alsi10mg Alloy, Edward Stugelmayer

Graduate Theses & Non-Theses

Additive manufacturing using laser powder bed fusion (AM-LPBF) methods have recently experienced rapid growth and development, having the potential to replace manufacturing by plastic deformation, precision machining, or casting. AM offers advantages such as the freedom to design highly complex geometries, time and cost savings through material usage efficiency and shortened production cycles, and the potential for improved mechanical properties. Process induced defects, however, result in degradation and scattering of mechanical properties and hinder the widespread adoption of AM-LPBF in industry. This investigation focuses on the effects of varying energy density and build orientation on the evolution of process induced …

Investigations Of Solid-State Sintering Behavior Of Binary Refractory Metal Oxide Systems, Maureen Chorney

Graduate Theses & Non-Theses

Refractory metals are commonly alloyed for improved corrosion resistance, thermal stability, and strength. In service, these alloys form highly stable oxides under mildly oxidizing conditions at relatively low temperatures. In order to recycle these materials, high temperature electrochemical processing is required to reduce the refractory metal oxides. To abet experimental evaluation of the electrochemical reduction process under development at the Idaho National Laboratory, binary mixtures of selected refractory metal oxide powders were sintered to produce cathode pellets, which could be suspended in the molten salt electrolyte during reduction experiments. Preparatory literature review revealed a paucity of published information relative to …

Evaluation Of Metallurgical And Mechanical Properties Of Alsi10mg Produced By Selective Laser Melting, Luke J. Suttey

Graduate Theses & Non-Theses

Selective laser melting (SLM) additive manufacturing (AM) of metal powders has long been a focus in the study of AM due to the possibility of weight reduction, complex shape formation, and production cost savings. Although applicable to a variety of metals SLM AM of the AlSi10Mg alloy was studied in an attempt to characterize the effect of processing parameter and build angle variation on the final microstructural, fractographic, and mechanical properties of parts produced without any thermal post-processing techniques. Research was conducted on five build angles (0°, 30°, 45°, 60°, and 90°), and three Global Energy Densities (GED) (37.15, 45.39, …

Structural And Photoluminescence Properties Of Zno Thin Films Deposited By Ultrasonic Spray Pyrolysis, Iwan Sugihartono, Erfan Handoko, Vivi Fauzia, Artoto Arkundato, Lara Permata Sari

Makara Journal of Technology

Zinc oxide (ZnO) thin films on a silicon (Si) (111) substrate were grown herein using ultrasonic spray pyrolysis at 450 °C with different Zn concentrations. The ZnO thin films had X-ray diffraction patterns of a polycrystalline hexagonal wurtzite structure. The (002) and (101) peak intensities changed under different Zn concentrations. Furthermore, according to Scherer's and Stokes–Wilson equations, the crystallite size and the internal strain of the ZnO thin films in the (002) and (101) peaks changed with the Zn concentration. Optically, the photoluminescence spectra indicated that the ratio of the UV/GB emission of the ZnO thin films was the highest …

An Exploratory Study Of Sukuk Utilisation For Transportation Infrastructure Development In Indonesia, Fiona Lamari, Ayomi Dita Rarasati, Meilia Evita

Makara Journal of Technology

Investment in infrastructure is one of the principal drivers of the growth of the economy. For that reason, the Indonesian government has proposed an investment budget in the railway and sea and air transport sectors over the next 10 years. In order to overcome the burden of direct outflows and for the future, a study was conducted to lay down the framework of Shariah-compliant payments for the development of infrastructure in Indonesia in the transport sector. This paper aims to explore the opportunity and implementation of sukuk utilisation to develop transportation infrastructure. Secondary data study and interviews were selected for …

Small-Signal-Stability Enhancement Using A Power-System Stabilizer Based On The Cuckoo-Search Algorithm Against Contingency N-1 In The Sulselrabar 150-Kv System, Muhammad Ruswandi Djalal, Muhammad Yusuf Yunus, Herlambang Setiadi, Awan Uji Krismanto

Makara Journal of Technology

Small-signal stability is one of the main factors limiting power transmission in conventional power systems. This concern is primarily handled by adding damper windings of a synchronous generator and power-system stabilizer (PSS). However, due to the impact of the N-1 contingency, damper windings and a conventional PSS are insufficient to overcome this problem. Proper placement and design of the PSS are crucial for improving stability. One approach to optimizing the placement and tuning of the PSS is to use an artificial-intelligence method. Here, the cuckoo-search algorithm (CSA) is proposed to optimize the PSS tuning and placement. Based on simulation, it …

Isolation And Molecular Weight Characterization Of Tetragonula Laeviceps Honey Protein, Muhamad Sahlan, Nurul Azizah, Kazuaki Hakamada, Keiichi Noguchi, Masafumi Yohda

Makara Journal of Technology

The concentration of protein in honey is lower than polysaccharide. However, recently the honey’s protein is intensively studied and it showed that protein also have several biological activities such as antibacterial activity. The purpose of this research is to isolate and characterize Tetragonula laeviceps honey protein by determining the molecular weight. Honey protein of Trigona laeviceps was isolated using ultra-filtration with the membrane’s size of 30 kDa, then concentrated using tube membrane size 10 kDa. Molecular weight was analyzed by SDS PAGE. From the analysis, there was major protein band in honey produced by Tetragona laeviceps identified. The produced molecular …

Prerequisites For Public Acceptance Of Waste-To-Energy Plants: Evidence From Germany And Indonesia, Uwe Lahl, Barbara Zeschmar-Lahl

Makara Journal of Technology

Construction of waste incinerators often encounters resistance from the public. The minimum requirements for the ac- ceptance of these installations include modern air pollution control (APC) technology and safe disposal of residues. Confidence in the statements of government and government agencies as well as on those who support is an important point of acceptance. Independent scientific bodies such as universities can help to make this happen. In the case of the installation of waste into energy (WtE), such scientific support can be the measurement of emissions and their evalua- tion. Many products that enter the waste stream contain heavy metals, …

Hybrid Brain-Computer Interface: A Novel Method On The Integration Of Eeg And Semg Signal For Active Prosthetic Control, Reza Darmakusuma, Ary Setijadi Prihatmanto, Adi Indrayanto, Tati Latifah Mengko

Makara Journal of Technology

This paper describes a novel method for controlling active prosthetics by integrating surface electromyography (sEMG) and electroencephalograph signals to improve its intuitiveness. This paper also compares the new method (RTA-2) with other existing methods (AND and OR) for controlling active prosthetics. Based on analysis, RTA-2 features higher true positive rate (TPR) and balanced accuracy (BA) than AND method. On the other hand, the new method (RTA-2) yields lower false detection rate (FPR) than OR method. Analysis also shows that RTA-2 possesses equal TPR, FPR, and BA with the detection of movement intention using sEMG-based system. Although the RTA-2 method shows …

Seismic Response Analysis Along The Coastal Area Of Bengkulu During The September 2007 Earthquake, Lindung Zalbuin Mase

Makara Journal of Technology

A strong earthquake of 8.4 Mw occurred at the Sumatra Subduction Zone in September 12, 2007. The area that underwent the impact of the earthquake was located along the coastal area of the Bengkulu Province. A seismic ground response study was then performed with reference to the event. Several site investigations, including standard penetration test and shear wave velocity tests, were conducted to understand the subsoil condition. The data were used to analyze a ground response during the earthquake. The amplification factor of each site was obtained, and a comparison of the spectral accelerations was performed. The results showed that …

Coax-Fed Dipole-Type Applicator For Hepatic Cancer Rf Ablation, Basari Basari, Aditya Rakhmadi, Kazuyuki Saito

Makara Journal of Technology

Cancer is the third leading cause of mortality in the world and is one of the most difficult diseases to detect and cure. This fact motivates us to investigate a treatment method by using radiofrequency (RF) ablation. RF ablation therapy kills cancer cells by electromagnetically heating them up. The treatment uses an applicator that is inserted into the body to heat the cells. The cancer cells are exposed to a temperature of more than 60 °C in short duration (a few seconds to a few minutes), thereby causing cell destruction locally. To ensure effective treatment, a minimally invasive method is …

Nanostructural Origin Of Semiconductivity And Large Magnetoresistance In Epitaxial Nico2O4/Al2O3 Thin Films, Congmian Zhen, Xiaozhe Zhang, Wengang Wei, Wenzhe Guo, Ankit Pant, Xiaoshan Xu, Jian Shen, Li Ma, Denglu Hou

Xiaoshan Xu Papers

Despite low resistivity (~1 mΩ cm), metallic electrical transport has not been commonly observed in inverse spinel NiCo₂O₄, except in certain epitaxial thin films. Previous studies have stressed the effect of valence mixing and the degree of spinel inversion on the electrical conduction of NiCo₂O₄ films. In this work, we studied the effect of nanostructural disorder by comparing the NiCo₂O₄ epitaxial films grown on MgAl₂O₄ (1 1 1) and on Al₂O₃ (0 0 1) substrates. Although the optimal growth conditions are similar for the …

Atomic Probe Tomography And Creep Deformation Studies Of Highly Dynamic Metallic Systems: Copper-Zirconium Based Metallic Glass Alloys And Tin-Based Alloy, Chetarpa Yipyintum

Chulalongkorn University Theses and Dissertations (Chula ETD)

The early crystallization process of a Cu-Zr binary metallic glass was investigated by transmission electron microscopy (TEM) and atomic probe tomography (APT). The microstructural analysis was carried out using different characterization methods to see if the phase separation in different chemical compositions and chemical short-range orders were investigated by applying heat treatment under argon atmosphere in differential scanning calorimetry (DSC) chamber. Such a difference in the atomic arrangement of a given amorphous metallic structure is important, the actual characterization of such small difference is not practically easy. For the reason that there is an effect of the sample preparation method …

Corrosion Performance Of Zirconium-Based Passivations On Electroplated Zinc Nickel, Madison Morgan Reed

Masters Theses

“Performance requirements for Department of Defense (DoD) electrical components include corrosion and electrical contact resistance. Historically, electroplated cadmium with a chromate conversion coating (CrCC) has been used to meet corrosion and contact resistance standards. However, replacements are needed for these materials because they are toxic and carcinogenic. Electroplated γ-ZnNi has been identified as an acceptable alternative to Cd. This study evaluated commercially available Zr-based thin films and sealers as passivations for potential replacement of CrCCs. Ten different passivations were tested and compared with bare γ-ZnNi. X-Bond and Zircobond passivations were found to provide some improvement to the bare ZnNi corrosion …