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Materials Science and Engineering Faculty Research & Creative Works

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Full-Text Articles in Materials Science and Engineering

Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant Sep 2022

Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

Extrusion-based 3D printing with rapidly hardening polymeric materials is capable of building almost any conceivable structure. However, concrete, one of the most widely used materials for large-scale structural components, is generally based on inorganic binder materials like Portland cement. Unlike polymeric materials, a lack of precise control of the extent and rate of solidification of cement-based suspensions is a major issue that affects the ability to 3D-print geometrically complex structures. Here, we demonstrate a novel method for controllable-rapid solidification of concentrated mineral suspensions that contain a polymer binder system based on epoxy and thiol precursors as well as one or …

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High-Entropy Boride–Carbide Ceramics By Sequential Boro/Carbothermal Synthesis, Steven M. Smith, Lun Feng, William Fahrenholtz, Greg Hilmas, Tieshu Huang Sep 2022

High-Entropy Boride–Carbide Ceramics By Sequential Boro/Carbothermal Synthesis, Steven M. Smith, Lun Feng, William Fahrenholtz, Greg Hilmas, Tieshu Huang

Materials Science and Engineering Faculty Research & Creative Works

A dual-phase high-entropy boride (HEB)/carbide (HEC) ceramic with a fine grain size was synthesized by a sequential boro/carbothermal process. In the first step, an Hf–Nb–Ta–Ti–Zr-containing carbide was synthesized by a carbothermal reduction of oxides followed by the reaction of the carbide with B4C and ZrH2 to convert part of the carbide to boride. The resulting composition was ∼29 vol% HEB with an average grain size of ∼1.1 μm. Solid solution formation occurred at the densification temperature of 1900°C resulting in a relative density higher than 99%. The Vickers hardness was 26.5 ± 1.4 GPa. This is the first report of …

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Global Tellurium Supply Potential From Electrolytic Copper Refining, Nedal T. Nassar, Haeyeon Kim, Max Frenzel, Michael S. Moats, Sarah M. Hayes Sep 2022

Global Tellurium Supply Potential From Electrolytic Copper Refining, Nedal T. Nassar, Haeyeon Kim, Max Frenzel, Michael S. Moats, Sarah M. Hayes

Materials Science and Engineering Faculty Research & Creative Works

The transition towards renewable energy requires increasing quantities of nonfuel mineral commodities, including tellurium used in certain photovoltaics. While demand for tellurium may increase markedly, the potential to increase tellurium supply is not well-understood. In this analysis, we estimate the quantity of tellurium contained in anode slimes generated by electrolytic copper refining by country between 1986 and 2018, including uncertainties. For 2018, the results indicate that 1930 (1500-2700, 95% confidence interval) metric tons of tellurium were contained in anode slimes globally. This is nearly quadruple the reported tellurium production for that year. China has the greatest potential to increase tellurium …

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Mechanical Activation And Cation Site Disorder In Mgal2o4, Cole A. Corlett, Matthias D. Frontzek, Nina Obradovic, Jeremy Lee Watts, William Fahrenholtz Sep 2022

Mechanical Activation And Cation Site Disorder In Mgal2o4, Cole A. Corlett, Matthias D. Frontzek, Nina Obradovic, Jeremy Lee Watts, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The synthesis and crystallographic site occupancy were investigated for MgAl2O4 with and without mechanical activation of the precursor powders. Heating to 1200 °C or higher resulted in the formation of a single spinel phase regardless of whether the powders were mechanically activated or not. Neutron diffraction analysis was used to determine cation site occupancy and revealed that mechanical activation resulted in a lower degree of cation site inversion compared to the nonactivated materials, which indicated that the powders were closer to thermodynamic equilibrium. This is the first study to characterize the effects of mechanical activation on crystallographic site occupancy in …

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Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas Sep 2022

Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

ZrB2 was mixed with 0.5 wt% carbon and up to 10 vol% ZrC and densified by hot-pressing at 2000 °C. All compositions were > 99.8% dense following hot-pressing. The dense ceramics contained 1–1.5 vol% less ZrC than the nominal ZrC addition and had between 0.5 and 1 vol% residual carbon. Grain sizes for the ZrB2 phase decreased from 10.1 µm for 2.5 vol% ZrC to 4.2 µm for 10 vol% ZrC, while the ZrC cluster size increased from 1.3 µm to 2.2 µm over the same composition range. Elastic modulus was ~505 GPa and toughness was ~2.6 MPa·m½ for all compositions. …

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Machine Learning Mosa Monitoring System, Aditya G. Manjunath, Sabahudin Vrtagic, Fatih Dogan, Milan Dordevic, Mileta Zarkovic, Jasmin Kevric, Goran Dobric Aug 2022

Machine Learning Mosa Monitoring System, Aditya G. Manjunath, Sabahudin Vrtagic, Fatih Dogan, Milan Dordevic, Mileta Zarkovic, Jasmin Kevric, Goran Dobric

Materials Science and Engineering Faculty Research & Creative Works

This research paper deals with the problem of Metal-Oxide Surge Arrester (MOSA) condition monitoring and a new methodology in surge arrester monitoring and diagnostics is presented. A machine learning algorithm (back propagation regression) is used to estimate the non-linearity coefficient of the surge arrester, based on operating voltage and leakage current of the arrester. Using a simulated system, this research investigates the possibility of application and efficiency of machine learning. It is shown that the applied learning algorithm results are competitive with the model results parameters calculated as R2 = 0.999 and mean absolute real error computed as 0.005 which …

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Superhard Single-Phase (Ti,Cr)B2 Ceramics, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Laura Silvestroni Aug 2022

Superhard Single-Phase (Ti,Cr)B2 Ceramics, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Laura Silvestroni

Materials Science and Engineering Faculty Research & Creative Works

A nominally pure and dense (Ti0.9Cr0.1)B2 ceramic was produced by spark plasma sintering of powders synthesized by boro/carbothermal reduction of oxides. The synthesized powders were a single phase and had an average particle of 0.4 ± 0.1 μm and an oxygen content of 1.2 wt%. Average Vickers hardness values of the resulting ceramics increased from 25.9 ± 0.8 GPa at a load of 9.81 N, to 46.3 ± 0.8 GPa at a load of 0.49 N. Compared to the nominally pure TiB2 ceramic obtained under the same processing conditions, the (Ti0.9Cr0.1)B2 ceramic had higher values under the same load due …

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Shape Memory Alloys Via Halide-Activated Pack Equilibration, Andrew S. King, Ryan D. Dempsey, David W. Lipke Aug 2022

Shape Memory Alloys Via Halide-Activated Pack Equilibration, Andrew S. King, Ryan D. Dempsey, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Fabrication of shape memory alloy (SMA) components based on NiTi is challenging due to the precision with which elemental composition and microstructure must be controlled during processing to achieve desired shape memory behavior. Herein, a method to control chemistry in an NiTi SMA via halide-activated pack equilibration (SHAPE) against a constant chemical potential reservoir is described. To demonstrate the efficacy of the SHAPE process, an initially titanium-deficient specimen (pure nickel foam) has been equilibrated against an excess of an intimately mixed two-phase pack (NiTi + Ti2Ni) in the presence of a vapor phase transport agent (iodine). The two-phase pack regulates …

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Elevated Temperature Thermal Properties Of Zrb2-B4c Ceramics, Eric W. Neuman, Matthew Thompson, William Fahrenholtz, Gregory E. Hilmas Aug 2022

Elevated Temperature Thermal Properties Of Zrb2-B4c Ceramics, Eric W. Neuman, Matthew Thompson, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

The elevated temperature thermal properties of zirconium diboride ceramics containing boron carbide additions of up to 15 vol% were investigated using a combined experimental and modeling approach. The addition of B4C led to a decrease in the ZrB2 grain size from 22 µm for nominally pure ZrB2 to 5.4 µm for ZrB2 containing 15 vol% B4C. The measured room temperature thermal conductivity decreased from 93 W/m·K for nominally pure ZrB2 to 80 W/m·K for ZrB2 containing 15 vol% B4C. The thermal conductivity also decreased as temperature increased. For nominally pure ZrB2, the thermal conductivity was 67 W/m·K at 2000 °C …

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Effect Of Grain Size On The Irradiation Response Of Grade 91 Steel Subjected To Fe Ion Irradiation At 300 °C, Jiaqi Duan, Haiming Wen, Li He, Kumar Sridharan, Andrew Hoffman, Maalavan Arivu, Xiaoqing He, Rinat Islamgaliev, Ruslan Valiev Jul 2022

Effect Of Grain Size On The Irradiation Response Of Grade 91 Steel Subjected To Fe Ion Irradiation At 300 °C, Jiaqi Duan, Haiming Wen, Li He, Kumar Sridharan, Andrew Hoffman, Maalavan Arivu, Xiaoqing He, Rinat Islamgaliev, Ruslan Valiev

Materials Science and Engineering Faculty Research & Creative Works

Irradiation using Fe ion at 300 °C up to 100 dpa was carried out on three variants of Grade 91 (G91) steel samples with different grain size ranges: fine-grained (FG, with blocky grains of a few micrometers long and a few hundred nanometers wide), ultrafine-grained (UFG, grain size of ~ 400 nm) and nanocrystalline (NC, lath grains of ~ 200 nm long and ~ 80 nm wide). Electron microscopy investigations indicate that NC G91 exhibit higher resistance to irradiation-induced defect formation than FG and UFG G91. In addition, nano-indentation studies reveal that irradiation-induced hardening is significantly lower in NC G91 …

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Room-Temperature Mechanical Properties Of A High-Entropy Diboride, Alec C. Murchie, Jeremy Lee Watts, William Fahrenholtz, Gregory E. Hilmas Jul 2022

Room-Temperature Mechanical Properties Of A High-Entropy Diboride, Alec C. Murchie, Jeremy Lee Watts, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties of a (Hf,Mo,Nb,Ta,W,Zr)B2 high-entropy ceramic were measured at room temperature. A two-step synthesis process was utilized to produce the (Hf,Mo,Nb,Ta,W,Zr)B2 ceramics. The process consisted of a boro/carbothermal reduction reaction followed by solid solution formation and densification through spark plasma sintering. Nominally, phase pure (Hf,Mo,Nb,Ta,W,Zr)B2 was sintered to near full density (8.98 g/cm3) at 2000°C. The mean grain size was 6 ± 2 µm with a maximum grain size of 17 µm. Flexural strength was 528 ± 53 MPa, Young's modulus was 520 ± 12 GPa, fracture toughness was 3.9 ± 1.2 MPa·m1/2, and hardness (HV0.2) was 33.1 …

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First-Principles Study Of The Thermal Properties Of Zr2c And Zr2co, Yue Zhou, William Fahrenholtz, Joseph T. Graham, Gregory E. Hilmas Jul 2022

First-Principles Study Of The Thermal Properties Of Zr2c And Zr2co, Yue Zhou, William Fahrenholtz, Joseph T. Graham, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

First-principles calculations of lattice thermal conductivities and thermodynamic properties of Zr2C and Zr2CO were performed using the quasi-harmonic approximation. Oxygen in the lattice gives Zr2CO higher bonding strength than Zr2C. Thus, the mechanical properties of Zr2C are enhanced when the vacancies in its crystal structure are filled with oxygen. Among the critical parameters that determine the lattice thermal conductivity, Zr2C has significantly higher Grüneisen parameters, thus Zr2C has lower lattice thermal conductivity than Zr2CO. In addition, Zr2CO has a higher heat capacity and thermal expansion coefficient than Zr2C at most temperatures. These results indicate that the addition of oxygen has …

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Tini-Based Bi-Metallic Shape-Memory Alloy By Laser-Directed Energy Deposition, Yitao Chen, Cesar Ortiz Rios, Braden Mclain, Joseph William Newkirk, Frank W. Liou Jun 2022

Tini-Based Bi-Metallic Shape-Memory Alloy By Laser-Directed Energy Deposition, Yitao Chen, Cesar Ortiz Rios, Braden Mclain, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In this study, laser-directed energy deposition was applied to build a Ti-rich ternary Ti-Ni-Cu shape-memory alloy onto a TiNi shape-memory alloy substrate to realize the joining of the multifunctional bi-metallic shape-memory alloy structure. The cost-effective Ti, Ni, and Cu elemental powder blend was used for raw materials. Various material characterization approaches were applied to reveal different material properties in two sections. The as-fabricated Ti-Ni-Cu alloy microstructure has the TiNi phase as the matrix with Ti2Ni secondary precipitates. The hardness shows no high values indicating that the major phase is not hard intermetallics. A bonding strength of 569.1 MPa …

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Tini-Based Bi-Metallic Shape-Memory Alloy By Laser-Directed Energy Deposition, Yitao Chen, Cesar Ortiz Rios, Braden Mclain, Joseph William Newkirk, Frank W. Liou Jun 2022

Tini-Based Bi-Metallic Shape-Memory Alloy By Laser-Directed Energy Deposition, Yitao Chen, Cesar Ortiz Rios, Braden Mclain, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In this study, laser-directed energy deposition was applied to build a Ti-rich ternary Ti–Ni–Cu shape-memory alloy onto a TiNi shape-memory alloy substrate to realize the joining of the multifunctional bi-metallic shape-memory alloy structure. The cost-effective Ti, Ni, and Cu elemental powder blend was used for raw materials. Various material characterization approaches were applied to reveal different material properties in two sections. The as-fabricated Ti–Ni–Cu alloy microstructure has the TiNi phase as the matrix with Ti2Ni secondary precipitates. The hardness shows no high values indicating that the major phase is not hard intermetallic. A bonding strength of 569.1 MPa was obtained …

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Thermal And Electrical Properties Of A High Entropy Carbide (Ta, Hf, Nb, Zr) At Elevated Temperatures, Evan C. Schwind, Michael J. Reece, Elinor Castle, William Fahrenholtz, Gregory E. Hilmas Jun 2022

Thermal And Electrical Properties Of A High Entropy Carbide (Ta, Hf, Nb, Zr) At Elevated Temperatures, Evan C. Schwind, Michael J. Reece, Elinor Castle, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

The thermal and electrical properties were measured for a high entropy carbide ceramic, consisting of (Hf, Ta, Zr, Nb)C. The ceramic was produced by spark plasma sintering a mixture of the monocarbides and had a relative density of more than 97.6%. The resulting ceramic was chemically homogeneous as a single-phase solid solution formed from the constituent carbides. The thermal diffusivity (0.045–0.087 cm2/s) and heat capacity (0.23–0.44 J/g•K) were measured from room temperature up to 2000°C. The thermal conductivity increased from 10.7 W/m•K at room temperature to 39.9 W/m•K at 2000°C. The phonon and electron contributions to the thermal conductivity were …

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Synthesis Of Dysprosium Oxychloride (Dyocl), Saehwa Chong, Brian J. Riley, José Marcial, Charmayne E. Lonergan, Derek A. Cutforth Jun 2022

Synthesis Of Dysprosium Oxychloride (Dyocl), Saehwa Chong, Brian J. Riley, José Marcial, Charmayne E. Lonergan, Derek A. Cutforth

Materials Science and Engineering Faculty Research & Creative Works

Dysprosium oxychloride, DyOCl, was synthesized using a simple hydrolysis method with DyCl3·6H2O. X-ray powder diffraction (XRD) data was used to determine the crystal structure. The DyOCl compound is isostructural to the matlockite (PbFCl) crystal structure and crystallizes in the tetragonal P4/nmm (#129) space group. The crystal structure contains the alternating cationic layers of (DyO)n and anionic layers of nCl− along the c-axis. The structural data including unit cell, volume, and density of DyOCl were compared to other rare-earth oxychloride data from the Inorganic Crystal Structure Database (ICSD) and our previous study on TbOCl. Fourier-transform …

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Solid-State Formation Mechanisms Of Core–Shell Microstructures In (Zr,Ta)B2 Ceramics, Anna N. Dorner, Frédéric Monteverde, William Fahrenholtz, Gregory E. Hilmas May 2022

Solid-State Formation Mechanisms Of Core–Shell Microstructures In (Zr,Ta)B2 Ceramics, Anna N. Dorner, Frédéric Monteverde, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Transition metal diborides with core–shell microstructures have demonstrated excellent mechanical properties at elevated temperatures. Previous studies concluded that core–shell microstructures were formed by liquid-assisted mass transport mechanisms, but in this study, we propose a solid-state formation mechanism for core-shell microstructures in (Zr,Ta)B2 ceramics produced by reaction hot pressing and in ZrB2-TaB2 diffusion couples. Diffusion couple experiments demonstrated that core–shell microstructures developed as a result of Ta diffusion along ZrB2 grain boundaries, which occurred concurrently with lattice diffusion of Ta into ZrB2. These findings suggest that with optimization of batching and processing parameters, core–shell diboride materials may be formed through solid-state …

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Pressureless Sintering Of Zirconium Diboride With Carbon And Boron Carbide Nanopowder, Eric W. Neuman, Gregory E. Hilmas, William Fahrenholtz May 2022

Pressureless Sintering Of Zirconium Diboride With Carbon And Boron Carbide Nanopowder, Eric W. Neuman, Gregory E. Hilmas, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Zirconium diboride ceramics with and without carbon and boron carbide nano powder additives were prepared by ball milling with ZrB2 grinding media and pressureless sintering. Additions of up to 1 wt% nano-B4C and 0.5 wt% C were made to the ZrB2 powder. The materials were then sintered between 1800 and 2300 °C for between 90 and 360 min in an Ar/10H2 atmosphere. After sintering at 2200 °C for 90 min, densities ranged from 88.3 to 90.7% for the ZrB2 with 0–1.0% nano-B4C addition. Carbon additions of 0.5 wt% and nano-B4C additions from 0 to 1.0 wt% resulted in densities ranging …

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Mechanical Properties Of Fusion Welded Ceramics In The Sic-Zrb2 And Sic-Zrb2-Zrc Systems, Jecee D. Jarman, William Fahrenholtz, Greg Hilmas, Jeremy Lee Watts, Derek S. King May 2022

Mechanical Properties Of Fusion Welded Ceramics In The Sic-Zrb2 And Sic-Zrb2-Zrc Systems, Jecee D. Jarman, William Fahrenholtz, Greg Hilmas, Jeremy Lee Watts, Derek S. King

Materials Science and Engineering Faculty Research & Creative Works

Mechanical properties of welded SiC-ZrB2 and SiC-ZrB2-ZrC ceramics were measured up to 1700 °C. Commercial powders were hot pressed, machined into coupons, and preheated to 1600 °C before joining the ceramics using either tungsten inert gas welding or plasma arc welding. Toughness of the parent materials was 3–4 MPa*m1/2 which decreased after welding to 2–2.5 MPa*m1/2. Strength of the SiC-ZrB2-ZrC parent material was ~700 MPa at 25 °C, ~300 MPa at 1700 °C, and retained 40–60% of this strength once welded. Strength of the SiC-ZrB2 parent material was ~600 MPa at 25 °C and 1700 °C and retained 20–30% of …

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Preparation Of Concrete Specimen For Internal Sulfate Attack Analysis Using Electron Backscatter Diffraction, R. Sharon Uwanyuze, Lucas Enright, Jiyao Zhang, Stefan Schafföner May 2022

Preparation Of Concrete Specimen For Internal Sulfate Attack Analysis Using Electron Backscatter Diffraction, R. Sharon Uwanyuze, Lucas Enright, Jiyao Zhang, Stefan Schafföner

Materials Science and Engineering Faculty Research & Creative Works

Concrete cores were obtained from houses in eastern Connecticut, USA, that had varying degrees of crumbling foundations and wall cracking. Electron backscatter diffraction (EBSD) was used simultaneously with energy dispersive X-ray spectroscopy to investigate the degradation of these samples. This combination allowed the precise correlation of elemental composition with mineral crystallography phase mapping. EBSD examination showed the presence of pyrrhotite, pyrite, and marcasite phases in some of the samples, whereas internal sulfate attack (ISA) is triggered by the release of sulfates through the oxidation of such iron sulfides. Secondary expansion products from ISA are associated with foundation cracking, wall bulging, …

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Effect Of Micro-Structural Dispersity Of Simo Ductile Iron On High Temperature Performance During Static Oxidation, Semen Naumovich Lekakh, Asebi Bofah, Larry A. Godlewski, Mei Li Apr 2022

Effect Of Micro-Structural Dispersity Of Simo Ductile Iron On High Temperature Performance During Static Oxidation, Semen Naumovich Lekakh, Asebi Bofah, Larry A. Godlewski, Mei Li

Materials Science and Engineering Faculty Research & Creative Works

High silicon and molybdenum (SiMo) ductile iron is commonly used for car exhaust systems, and its micro-structural dispersity depends on intrinsic parameters, which include alloy composition and inoculation efficiency, as well as extrinsic factors, such as casting wall thickness and molding material, which define cooling rate during solidification. Micro-structural dispersity is referred to as the degree of heterogeneity of sizes of structural constituencies within the microstructure. A variation in the micro-structural dispersity could impact the high temperature performance of SiMo ductile iron during static oxidation and transient thermo-mechanical loading conditions. In this study, static high temperature tests were performed on …

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Effects Of Carrier, Leveller, And Booster Concentrations On Zinc Plating From Alkaline Zincate Baths, Abdul Jalil Mohammed, Michael S. Moats Apr 2022

Effects Of Carrier, Leveller, And Booster Concentrations On Zinc Plating From Alkaline Zincate Baths, Abdul Jalil Mohammed, Michael S. Moats

Materials Science and Engineering Faculty Research & Creative Works

Organic additives are required for alkaline zincate plating baths to obtain an acceptable coating on steel for corrosion protection. The effects and possible interactions of three commercial additives (Eldiem Carrier, Eldiem Booster, and Bright Enhancer 2x on zinc electrodeposition from a high-concentration alkaline zincate bath were investigated. Visually acceptable deposits were produced within the current density range of 130 to 430 A m-2 for most additive conditions examined. Over concentration ranges examined, decreasing the booster concentration led to brighter zinc deposits, and an interaction between the carrier and the booster was detected. The additives fostered the formation of compact …

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The Oxidation Of The Hisimo Cast Irons Alloyed With Cr/Al At 800 °C, Wenhui Zhu, Bruce A. Pint, Yang Huo, Larry Godlewski, Bita Ghaffari, Simon Lekakh, Carlos Engler-Pinto, Mei Li Apr 2022

The Oxidation Of The Hisimo Cast Irons Alloyed With Cr/Al At 800 °C, Wenhui Zhu, Bruce A. Pint, Yang Huo, Larry Godlewski, Bita Ghaffari, Simon Lekakh, Carlos Engler-Pinto, Mei Li

Materials Science and Engineering Faculty Research & Creative Works

To improve the oxidation resistance of cast iron containing Si and Mo (HiSiMo), 1wt.% Cr and 3wt.% Al were added into the base alloy to improve high temperature oxidation resistance for exhaust manifold applications. Oxidation tests were performed in both dry and wet air (air + 10% H2O) at 800 °C for 1, 10, 24, and 50 h. The mass change and oxide thickness were measured to evaluate the oxidation resistance. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS) and transmission electron microscopy (TEM) were employed to characterize the oxidized samples. The results showed that the additions of Al …

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Effects Of Carrier, Leveller, And Booster Concentrations On Zinc Plating From Alkaline Zincate Baths, Abdul Jalil Mohammed, Michael S. Moats Apr 2022

Effects Of Carrier, Leveller, And Booster Concentrations On Zinc Plating From Alkaline Zincate Baths, Abdul Jalil Mohammed, Michael S. Moats

Materials Science and Engineering Faculty Research & Creative Works

Organic additives are required for alkaline zincate plating baths to obtain an acceptable coating on steel for corrosion protection. The effects and possible interactions of three commercial additives (Eldiem Carrier, Eldiem Booster, and Bright Enhancer 2x on zinc electrodeposition from a high-concentration alkaline zincate bath were investigated. Visually acceptable deposits were produced within the current density range of 130 to 430 A m−2 for most additive conditions examined. Over concentration ranges examined, decreasing the booster concentration led to brighter zinc deposits, and an interaction between the carrier and the booster was detected. The additives fostered the formation of compact and …

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Effect Of Micro-Structural Dispersity Of Simo Ductile Iron On High Temperature Performance During Static Oxidation, Simon N. Lekakh, Asebi Bofah, Larry A. Godlewski, Mei Li Apr 2022

Effect Of Micro-Structural Dispersity Of Simo Ductile Iron On High Temperature Performance During Static Oxidation, Simon N. Lekakh, Asebi Bofah, Larry A. Godlewski, Mei Li

Materials Science and Engineering Faculty Research & Creative Works

High silicon and molybdenum (SiMo) ductile iron is commonly used for car exhaust systems, and its micro-structural dispersity depends on intrinsic parameters, which include alloy composition and inoculation efficiency, as well as extrinsic factors, such as casting wall thickness and molding material, which define cooling rate during solidification. Micro-structural dispersity is referred to as the degree of heterogeneity of sizes of structural constituencies within the microstructure. A variation in the micro-structural dispersity could impact the high temperature performance of SiMo ductile iron during static oxidation and transient thermo-mechanical loading conditions. In this study, static high temperature tests were performed on …

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Is There Any Role Of Reduction Mammoplasty In Decreasing Breast Cancer Risk In Gigantomastia?, Fatma Nilay Tutak, Fatih Dogan Mar 2022

Is There Any Role Of Reduction Mammoplasty In Decreasing Breast Cancer Risk In Gigantomastia?, Fatma Nilay Tutak, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Aim: Large breasts create psychological and physical problems in women, all of whom must also keep in mind the common problem of breast cancer. In the present study we examine the effect of breast reduction surgery on breast cancer risk. Materials and Methods: Our retrospective study is based on the records (between June 1, 2014, and June 30, 2019) of patients who underwent breast reduction surgery in the Plastic, Reconstructive and Aesthetical Surgery clinic of a training and research hospital. Statistical analyses were conducted using IBM SPSS Statistics (Version 25.0. Armonk, NY:IBMCorp.). Normal distribution of the data was analyzed with …

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Investigation Of Mechanical Properties Of Parts Fabricated With Gas- And Water-Atomized 304l Stainless Steel Powder In The Laser Powder Bed Fusion Process, M. Hossein Sehhat, Austin T. Sutton, Chia Hung Hung, Joseph William Newkirk, Ming-Chuan Leu Mar 2022

Investigation Of Mechanical Properties Of Parts Fabricated With Gas- And Water-Atomized 304l Stainless Steel Powder In The Laser Powder Bed Fusion Process, M. Hossein Sehhat, Austin T. Sutton, Chia Hung Hung, Joseph William Newkirk, Ming-Chuan Leu

Materials Science and Engineering Faculty Research & Creative Works

The use of gas-atomized powder as the feedstock material for the laser powder bed fusion (LPBF) process is common in the additive manufacturing (AM) community. Although gas-atomization produces powder with high sphericity, its relatively expensive production cost is a downside for application in AM processes. Water atomization of powder may overcome this limitation due to its low-cost relative to the gas-atomization process. In this work, gas- and water-atomized 304L stainless steel powders were morphologically characterized through scanning electron microscopy (SEM). The water-atomized powder had a wider particle size distribution and exhibited less sphericity. Measuring powder flowability using the Revolution Powder …

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Dissolution Amplification By Resonance And Cavitational Stimulation At Ultrasonic And Megasonic Frequencies, Ross A. Arnold, Shiqi Dong, Longwen Tang, Dale Prentice, Marie Collin, Juan Carlos Vega-Vila, Amaya Hernandez, Erika Callagon La Plante, Kirk Ellison, Aditya Kumar, Samanvaya Srivastava, Mathieu Bauchy, Dante Simonetti, Gaurav N. Sant Feb 2022

Dissolution Amplification By Resonance And Cavitational Stimulation At Ultrasonic And Megasonic Frequencies, Ross A. Arnold, Shiqi Dong, Longwen Tang, Dale Prentice, Marie Collin, Juan Carlos Vega-Vila, Amaya Hernandez, Erika Callagon La Plante, Kirk Ellison, Aditya Kumar, Samanvaya Srivastava, Mathieu Bauchy, Dante Simonetti, Gaurav N. Sant

Materials Science and Engineering Faculty Research & Creative Works

Acoustic stimulation offers a green pathway for the extraction of valuable elements such as Si, Ca, and Mg via solubilization of minerals and industrial waste materials. Prior studies have focused on the use of ultrasonic frequencies (20-40 kHz) to stimulate dissolution, but mega sonic frequencies (≥1 MHz) offer benefits such as matching of the resonance frequencies of solute particles and an increased frequency of cavitation events. Here, based on dissolution tests of a series of minerals, it is found that dissolution under resonance conditions produced dissolution enhancements between 4x-to-6x in Si-rich materials (obsidian, albite, and quartz). Cavitational collapse induced by …

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Effect Of Processing Parameters And Build Orientation On Microstructure And Performance Of Aisi Stainless Steel 304l Made With Selective Laser Melting Under Different Strain Rates, Tan Pan, Xinchang Zhang, Aaron Flood, Sreekar Karnati, Wei Li, Joseph William Newkirk, Frank W. Liou Feb 2022

Effect Of Processing Parameters And Build Orientation On Microstructure And Performance Of Aisi Stainless Steel 304l Made With Selective Laser Melting Under Different Strain Rates, Tan Pan, Xinchang Zhang, Aaron Flood, Sreekar Karnati, Wei Li, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

Selective laser melting (SLM) process allows greater geometry flexibility; therefore, it has become more widespread in its deployment in the industry for fabricating metal alloys. However, a material characterization study is needed in order to understand better the correlation between the process, microstructure, and performance. In the current study, the raw SLM fabricated AISI stainless steel 304 L was fabricated with different processing parameters and build orientations (horizontal, inclined, and vertical). The tensile behavior was evaluated under different strain rates (0.0001/s, 0.001/s, 0.01/s, and 0.1/s) and then compared to commercial cold-rolled and annealed counterparts. Grain structures, tensile strength, elongation-to-failure, strain …

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Control Of High-Temperature Static And Transient Thermomechanical Behavior Of Simo Ductile Iron By Al Alloying, Semen Naumovich Lekakh, Catherine E. Johnson, L. Godlewski, Mei Li Feb 2022

Control Of High-Temperature Static And Transient Thermomechanical Behavior Of Simo Ductile Iron By Al Alloying, Semen Naumovich Lekakh, Catherine E. Johnson, L. Godlewski, Mei Li

Materials Science and Engineering Faculty Research & Creative Works

Silicon and molybdenum (SiMo) ductile iron is commonly used for exhaust manifolds because these components experience thermal cycling in oxidizing environment, which requires resistance to fatigue during transient thermomechanical loads. Previous studies have demonstrated that alloying elements, such as Al, to SiMo ductile iron reduces the amount of surface degradation during static high-temperature exposure. However, deterioration of sphericity of the graphite nodules and a decrease in ductility could affect the tendency of cracking during thermal cycling. In this article, the effect of Al alloying on static and transient thermomechanical behavior of SiMo ductile iron was investigated to optimize the amount …

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