Open Access. Powered by Scholars. Published by Universities.®

Metallurgy Commons

Open Access. Powered by Scholars. Published by Universities.®

2,729 Full-Text Articles 4,430 Authors 768,961 Downloads 56 Institutions

All Articles in Metallurgy

Faceted Search

2,729 full-text articles. Page 3 of 52.

The Influence Of Ti, Nb And V On The Hot Ductility Of As-Cast Microalloyed Steels, Madhuri Varadarajan, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh 2020 Missouri University of Science and Technology

The Influence Of Ti, Nb And V On The Hot Ductility Of As-Cast Microalloyed Steels, Madhuri Varadarajan, Laura Bartlett, Ronald J. O'Malley, Semen Naumovich Lekakh

Materials Science and Engineering Faculty Research & Creative Works

Microalloying with Ti, Nb and V, both individually and in combination, is a common method for producing steels with high strength and toughness. However, interaction with other elements and impurities can lead to cracking during continuous casting and rolling. The hot ductility of commercially cast V, Nb and Nb-V-Ti steels has been investigated using two experimental methods: tensile testing utilizing a servo-hydraulic load frame with a resistance furnace and thermomechanical testing using rapid joule heating. The temperature-dependent ductility of these steels is compared for both test methods. Factors that influence the ductility of these steels are discussed.


A Modified Johnson-Cook Model Incorporating The Effect Of Grain Size On Flow Stress, S. Ganguly, Mario F. Buchely, K. Chandrashekhara, Semen Naumovich Lekakh, Ronald J. O'Malley 2020 Missouri University of Science and Technology

A Modified Johnson-Cook Model Incorporating The Effect Of Grain Size On Flow Stress, S. Ganguly, Mario F. Buchely, K. Chandrashekhara, Semen Naumovich Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties of steel are influenced by grain size, which can change through mechanisms such as nucleation and growth at elevated temperatures. However, the classic Johnson-Cook model that is widely used in hot deformation simulations does not consider the effect of grain size on flow stress. In this study, the Johnson-Cook model was modified to incorporate the effects of austenite grain size on flow stress. A finite element model was employed to characterize the effects of grain size on the flow stress for different steel grades over a range of temperatures (900⁰ to 1300⁰). Simulation results show good agreement ...


Scale Formation On 430 Stainless Steel In A Simulated Slab Combustion Reheat Furnace Atmosphere, Richard Osei, Semen Naumovich Lekakh, Ronald J. O'Malley 2020 Missouri University of Science and Technology

Scale Formation On 430 Stainless Steel In A Simulated Slab Combustion Reheat Furnace Atmosphere, Richard Osei, Semen Naumovich Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Scale formed during slab reheating can be difficult to remove by high-pressure descaling, having a negative impact hot roll surface quality. A large-capacity thermogravimetric apparatus that replicates the combustion atmosphere and temperature in a slab reheat furnace was used to investigate scale formation on 430 stainless steel. Effects of reheating parameters (temperature, time and atmosphere) on oxidation kinetics were investigated. Oxidized samples were characterized by scanning electron microscopy, Raman spectroscopy and x-ray diffraction to document the microstructure and morphology of scale. Mechanisms for the formation of multi-layered oxide structures that complicate oxidation kinetics and scale removal are discussed.


In Situ Transmission Electron Microscopy Study Of Conductive Filament Formation In Copper Oxides, Xinchun Tian, Sanaz Yazdanparast, Geoff Brennecka, Xiaoli Tan 2020 Iowa State University

In Situ Transmission Electron Microscopy Study Of Conductive Filament Formation In Copper Oxides, Xinchun Tian, Sanaz Yazdanparast, Geoff Brennecka, Xiaoli Tan

Materials Science and Engineering Publications

The structural and electrical property changes of two types of copper oxides (CuO and Cu 2 O) under voltage bias are studied with in situ transmission electron microscopy (TEM). The phases of different materials are confirmed with electron diffraction. In both types of oxides, dynamic conductive path formation and dissolution are observed. The decrease in resistance of CuO film is found to be accompanied with the formation of Cu 4 O 3 phase where the electric field strength is highest. We also find that the decrease in resistivity of Cu 2 O film is more extensive and occurs in an ...


Synthesis Of Interface-Driven Tunable Bandgap Metal Oxides, Boyce S. Chang, Andrew Martin, Brijith Thomas, Ang Li, Rick W. Dorn, Jinlong Gong, Aaron J. Rossini, Martin M. Thuo 2020 Iowa State University

Synthesis Of Interface-Driven Tunable Bandgap Metal Oxides, Boyce S. Chang, Andrew Martin, Brijith Thomas, Ang Li, Rick W. Dorn, Jinlong Gong, Aaron J. Rossini, Martin M. Thuo

Chemistry Publications

Mixed bandgap and bandgap tunability in semiconductors is critical in expanding their use. Composition alterations through single-crystal epitaxial growth and the formation of multilayer tandem structures are often employed to achieve mixed bandgaps, albeit with limited tunability. Herein, self-assembled one-dimensional coordination polymers provide facile synthons and templates for graphitic C-doped mesoporous oxides, gC-β-Ga2O3 or gC-In2O3 via controlled oxidative ligand ablation. These materials have mixed bandgaps and colors, depending on amount of gC present. The carbon/oxide interface leads to induced gap states, hence, a stoichiometrically tunable band structure. Structurally, a multiscale porous network percolating throughout the material is realized. The ...


Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong 2020 Boise State University

Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong

Boise State University Theses and Dissertations

For magnetic shape memory (MSM) alloys, a magnetic field stimulates a shape change. We use the shape change to build devices such as micro-actuators, sensors, and microfluidic pumps. Currently, (as a novel technology,) devices suffer from some material and magnetic driver shortcomings. Here we address the issues related to operating temperature, repeatability, failure, and magnetic driver development. To increase the operating temperature of the MSM material, we alloyed Fe and Cu to Ni-Mn-Ga. We showed that the element-specific contribution to the valence electron density as parameter systematically determines the effect of each element on the variation of the martensite transformation ...


From A Conventional Ferromagnetism To A Frustrated Magnetism: An Unexpected Role Of Fe In Nd(Al1-Xfex)2 (X ≤ 0.2), Yuanyuan Wu, Yaroslav Mudryk, Anis Biswas, Vitalij K. Pecharsky, Yi Long 2020 Ames Laboratory, University of Science and Technology Beijing, and Chinese Academy of Science

From A Conventional Ferromagnetism To A Frustrated Magnetism: An Unexpected Role Of Fe In Nd(Al1-Xfex)2 (X ≤ 0.2), Yuanyuan Wu, Yaroslav Mudryk, Anis Biswas, Vitalij K. Pecharsky, Yi Long

Ames Laboratory Accepted Manuscripts

The structure and magnetic properties of Nd(Al1-xFex)2 alloys with x = 0, 0.05, 0.1 and 0.2, which adopt cubic MgCu2-type structure with space group Fd(bar over 3)m, are studied using x-ray powder diffraction, static and dynamic magnetization, and calorimetric measurements. The lattice constant decreases linearly with increasing Fe content from 8.0106(4) Å to 7.9044(4) Å. Large thermal irreversibilities between zero-field-cooled and field-cooled conditions are observed for all substituted samples. The magnetic transition temperatures exhibit a minimum for x = 0.1, and coercive fields at 2 K increase from 70 Oe ...


A Spatially Distributed Fiber-Optic Temperature Sensor For Applications In The Steel Industry, Muhammad Roman, Damilola Balogun, Yiyang Zuang, Rex E. Gerald II, Laura Bartlett, Ronald J. O'Malley, Jie Huang 2020 Missouri University of Science and Technology

A Spatially Distributed Fiber-Optic Temperature Sensor For Applications In The Steel Industry, Muhammad Roman, Damilola Balogun, Yiyang Zuang, Rex E. Gerald Ii, Laura Bartlett, Ronald J. O'Malley, Jie Huang

Materials Science and Engineering Faculty Research & Creative Works

This paper presents a spatially distributed fiber-optic sensor system designed for demanding applications, like temperature measurements in the steel industry. The sensor system employed optical frequency domain reflectometry (OFDR) to interrogate Rayleigh backscattering signals in single-mode optical fibers. Temperature measurements employing the OFDR system were compared with conventional thermocouple measurements, accentuating the spatially distributed sensing capability of the fiber-optic system. Experiments were designed and conducted to test the spatial thermal mapping capability of the fiber-optic temperature measurement system. Experimental simulations provided evidence that the optical fiber system could resolve closely spaced temperature features, due to the high spatial resolution and ...


A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion, Luis Fernando Silva Velasco 2020 Western Michigan University

A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion, Luis Fernando Silva Velasco

Master's Theses

Metal additive manufacturing is an enabling technology for the rapid prototyping and manufacturing of geometrically complex parts that would otherwise be difficult or impossible to manufacture. However, the manufacturing process can produce undesired residual stresses and distortions. The first part of the work describes the implementation of a multiscale, thermo-mechanical simulation modeling the metal powder bed fusion additive manufacturing process. NASA’s Micromechanics Analysis Code was is to incorporate the microscale effects of an evolving material porosity on the predicted macroscale residual fields. The simulation shows that modeling an evolving material porosity, as the material transitions from a metal powder ...


Additive Manufacturing Of Highly Dense Anisotropic Nd–Fe–B Bonded Magnets, Kinjal Gandha, Ikenna C. Nlebedim, Vlastimil Kunc, Edgar Lara-Curzio, Robert Fredette, M. Parans Paranthaman 2020 Ames Laboratory

Additive Manufacturing Of Highly Dense Anisotropic Nd–Fe–B Bonded Magnets, Kinjal Gandha, Ikenna C. Nlebedim, Vlastimil Kunc, Edgar Lara-Curzio, Robert Fredette, M. Parans Paranthaman

Ames Laboratory Accepted Manuscripts

Extrusion based big area additive manufacturing process is utilized for fabrication of dense anisotropic bonded magnets. High loading fraction (≥70 vol%) of magnequench anisotropic Nd–Fe–B powder in nylon is used for preparing anisotropic bonded magnets. A higher energy product of ~143.2 kJ/m3 is obtained for the post printed magnetic field aligned at 1 Tesla. These findings make an important step towards the fabrication of gap magnets with energy product between ferrite and Nd–Fe–B sintered magnets. Moreover, printed bonded magnets exhibited better thermal stability, mechanical properties and superior magnetic properties compared to commercial injection molded ...


Boron Nitride Nanotube Based Lightweight Metal Matrix Composites: Microstructure Engineering And Stress-Transfer Mechanics, Pranjal Nautiyal 2020 Florida International University

Boron Nitride Nanotube Based Lightweight Metal Matrix Composites: Microstructure Engineering And Stress-Transfer Mechanics, Pranjal Nautiyal

FIU Electronic Theses and Dissertations

Lightweight metals, such as Aluminum, Magnesium and Titanium, are receiving widespread attention for manufacturing agile structures. However, the mechanical strength of these metals and their alloys fall short of structural steels, curtailing their applicability in engineering applications where superior load-bearing ability is required. There is a need to effectively augment the deformation- and failure-resistance of these metals without compromising their density advantage.

This dissertation explores the mechanical reinforcement of the aforementioned lightweight metal matrices by utilizing Boron Nitride Nanotube (BNNT), a 1D nanomaterial with extraordinary mechanical properties. The nanotubes are found to resist thermo-oxidative transformations up to ~750°C, establishing ...


Effects Of Surface Finish On High Cycle Fatigue Of Inconel 718, Jessica A. McRoskey, Matthew Busse 2020 California Polytechnic State University, San Luis Obispo

Effects Of Surface Finish On High Cycle Fatigue Of Inconel 718, Jessica A. Mcroskey, Matthew Busse

Materials Engineering

Inconel 718 is a nickel-based superalloy and commonly used rocket engine material due to its excellent properties at elevated temperatures. Its fatigue life relies heavily on the surface roughness, as fatigue introduces and propagates cracks at the surface. Part standards set by Aerojet Rocketdyne typically necessitate surface roughness values from 64 to 125 Ra. However, surface topography and residual stresses incurred from the finishing process also affect the fatigue performance. The specific goal of the project is to perform a literature review and write experimental methods to determine how the surface roughness, topography, and residual stresses from turning, grit blasting ...


The Effect Of Distal Core Flattening And Heat Treatment On 304 Stainless Steel Guide Wires, Andrew Spencer Yap, Bryce Eric Veit, Matthew Frederick Lopez Villena 2020 California Polytechnic State University, San Luis Obispo

The Effect Of Distal Core Flattening And Heat Treatment On 304 Stainless Steel Guide Wires, Andrew Spencer Yap, Bryce Eric Veit, Matthew Frederick Lopez Villena

Materials Engineering

The mechanical response of 304 stainless steel guide wires due to different temper conditions and amounts of flattening is to be explored in this project. For this specific project, there is no public literature on the mechanical properties of guide wires with the above conditions through tensile testing or Turns to Failure Testing. To address this, the project with Abbott Vascular will measure the mechanical properties of guide wires using the aforementioned factors. Due to a lack of previous literature on this research topic, there are no quantitative goals for the project, however, any new research compiled in this area ...


Microstructure And Tensile Properties Of Close-Die Forged Ti-6al-4v Aircraft Engine Mount, Renee Roeder, Nick Chen, Michael Viksne 2020 California Polytechnic State University, San Luis Obispo

Microstructure And Tensile Properties Of Close-Die Forged Ti-6al-4v Aircraft Engine Mount, Renee Roeder, Nick Chen, Michael Viksne

Materials Engineering

The microstructural characteristics of a Ti-6Al-4V close-die forging that passes yield strength specifications are examined and found to be consistent with literature recommendations. Originally, the intent was to compare the microstructure of a forging that passed specification to the microstructure of a forging that did not pass specifications using the imaging software ImageJ. Due to time and safety constraints considering the COVID-19 pandemic, the data that is presented is incomplete data on only the forging that passes specifications. There are no comparisons between the forging that did not pass and the forging that passed.


Non-Equilibrium Growth Of Metal Clusters On A Layered Material: Cu On Mos2, Dapeng Jing, Ann Lii-Rosales, King C. Lai, Qiang Li, Jaeyoun Kim, Michael C. Tringides, James W. Evans, Patricia A. Thiel 2020 Iowa State University and Ames Laboratory

Non-Equilibrium Growth Of Metal Clusters On A Layered Material: Cu On Mos2, Dapeng Jing, Ann Lii-Rosales, King C. Lai, Qiang Li, Jaeyoun Kim, Michael C. Tringides, James W. Evans, Patricia A. Thiel

Chemistry Publications

We use a variety of experimental techniques to characterize Cu clusters on bulk MoS2 formed via physical vapor deposition of Cu in ultrahigh vacuum, at temperatures ranging from 300 K to 900 K. We find that large facetted clusters grow at elevated temperatures, using high Cu exposures. The cluster size distribution is bimodal, and under some conditions, large clusters are surrounded by a denuded zone. We propose that defect-mediated nucleation, and coarsening during deposition, are both operative in this system. At 780 K, a surprising type of facetted cluster emerges, and at 900 K this type predominates: pyramidal clusters with ...


Development Of Mischmetal–Fe–Co–B Permanent Magnet Alloys Via High-Throughput Methods, Rakesh P. Chaudhary, Kinjal H. Gandha, Fanqiang Meng, Emrah Simsek, Ikenna C. Nlebedim, Orlando Rios, Matthew J. Kramer, Ryan T. Ott 2020 Ames Laboratory

Development Of Mischmetal–Fe–Co–B Permanent Magnet Alloys Via High-Throughput Methods, Rakesh P. Chaudhary, Kinjal H. Gandha, Fanqiang Meng, Emrah Simsek, Ikenna C. Nlebedim, Orlando Rios, Matthew J. Kramer, Ryan T. Ott

Ames Laboratory Accepted Manuscripts

Additive manufacturing synthesis using laser engineered net shaping (LENS) is utilized to rapidly print libraries of mischmetal (MM = La, Ce, Nd, and Pr) containing R2TM14B alloys (R = MM + separated Nd and TM = Fe and Co) enabling robust evaluation of physical properties over a wide composition range. High-throughput characterization of the magnetic and thermal properties are used to identify compositions for potential high-temperature, high-performance permanent magnets with reduced critical rare-earth elements. Improved Curie temperature (Tc ∼ 450 °C) is obtained with substitution of Fe by Co in pseudoternary R2TM14B alloys. Furthermore, a 4-fold decrease in the Nd content can be achieved ...


Atomic Cooperation In Enhancing Magnetism: (Fe, Cu)-Doped Ceco5, Renu Choudhary, Andriy Palasyuk, Ikenna C. Nlebedim, Ryan T. Ott, Durga Paudyal 2020 Ames Laboratory

Atomic Cooperation In Enhancing Magnetism: (Fe, Cu)-Doped Ceco5, Renu Choudhary, Andriy Palasyuk, Ikenna C. Nlebedim, Ryan T. Ott, Durga Paudyal

Ames Laboratory Accepted Manuscripts

Developing permanent magnet alloys with decreased critical elements (e.g., Nd, Dy, and Co) requires identifying compositions and structures with uniaxial magneto-crystalline anisotropy energy (MAE), large magnetization, and a high ferromagnetic transition temperature (Curie temperature - TC). One approach to minimizing the critical elements in potential permanent magnet alloys is to use overly produced Ce, which is less critical. Furthermore, reducing Co content in RCo5 (R = Rare Earth) alloys is necessary since Co is also a critical element. An obvious choice for decreasing Co content is a substitution with non-critical Fe. However, the Fe is not stable in the lattice ...


Selective Laster Melting 17 -4 Ph Stainless Steel And The Effect Of Varied Thermal Treatments On Fatigue Behavior., Sean Daniel Dobson 2020 University of Louisville

Selective Laster Melting 17 -4 Ph Stainless Steel And The Effect Of Varied Thermal Treatments On Fatigue Behavior., Sean Daniel Dobson

Electronic Theses and Dissertations

Fatigue failure is the leading source of loss in industry. In order for new means of manufacturing to move towards mainstream use a complete understanding of material and mechanical behavior must be gained. This endeavor seeks to aide in that task by observing the fatigue behavior of selective laser melting (SLM) additive manufacturing (AM) specimens and the effect of differing thermal treatment conditions for an optimized AM process. Stainless steel 17-4 PH specimens were fabricated using SLM AM and thermally treated to three conditions: as-built, solutionized and hardened, and direct hardened. These specimens were characterized for material (powder quality, density ...


Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh 2020 University of Louisville

Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh

Electronic Theses and Dissertations

Additive manufacturing (AM) is at the mainstream to cater the needs for rapid tooling and small-scale part production. The metal AM of complex geometries is widely accepted and promoted in the industry. While several metal AM technologies exist and are matured to a level where expectation in terms of design and properties are possible to realize. But the metal AM suffers from the heavy expense to acquire equipment, isotropic property challenges, and potential hazards to work with loose reactive metal powder. With this motivation, the dissertation aims to develop the fundamental aspects to print metal parts with bound Ti-6Al-4V powder ...


Defect Characterization Of Additively Manufactured Parts, Sabrina D'Alesandro, Joy Gockel, Andrew Harvey 2020 Wright State

Defect Characterization Of Additively Manufactured Parts, Sabrina D'Alesandro, Joy Gockel, Andrew Harvey

Symposium of Student Research, Scholarship, and Creative Activities Materials

This document describes various image processing techniques to be used for defect characterization of additively manufactured parts. This will help the reader gain knowledge of materials science engineering and the nuances in analyzing data from image processing software.

Additive manufacturing is shaping the manufacturing world through simplistic household printers’ to more complex metal printers used for a variety of applications. Specifically, laser powder bed fusion (LPBF) is an additive manufacturing process that deposits metal powder over the build plate and melts it with a laser in the shape of the build part. In order to make LPBF more efficient with ...


Digital Commons powered by bepress