Metallurgy Commons^™

Mechanical Characterization And Evaluation Of Additively Manufactured Titanium 5v-5mo-5al-3cr Alloy, Zachary Casias

Mechanical Engineering ETDs

Ti-5V-5Mo-5Al-3Cr (Ti-5553) is a near beta titanium alloy commonly used in aerospace applications. It is currently being explored for additive manufacturing (AM), but the fatigue behavior of this AM alloy needs to be well-understood for adoption in aerospace applications. The present work examines the tensile and fatigue behavior of LPBF manufactured Ti-5553. The effect of post-print heat treatments, effects of surface roughness, and print defects on the mechanical properties of AM Ti-5553 were also evaluated. Fatigue lives of as-LPBF and BAA material are nearly identical, and both are far below the fatigue lives of conventionally manufactured Ti-5553 of 350 MPa. …

Thermo-Gravimetric Analysis Of Variables Of Oxidization, Clark Nguyen, Mario F. Buchely

Undergraduate Research Conference at Missouri S&T

Oxidation phenomena play a critical role in high temperature metallurgical processing and the performance during life cycle of components made of both high and low alloy steels. Therefore, the development of a precise experimental methodology to quantify oxidation processes is critically important. This report summarizes my experimental study of the oxidation behavior of high and low alloy steel, including kinetics of surface oxide layer formation and spallation. The focus of study was in determining the complex interactions between alloying elements in steel matrix and oxidation environment, composition and surface morphology of formed oxides. This report will also explore how the …

Thermogravimetric Analysis Of High & Low Alloy Steel, Clark Nguyen

Undergraduate Research Conference at Missouri S&T

Oxidation phenomena play a critical role in high temperature metallurgical processing and the performance during life cycle of components made of both high and low alloy steels. Therefore, the development of a precise experimental methodology to quantify oxidation processes is critically important. This report summarizes my experimental study of the oxidation behavior of high and low alloy steel, including kinetics of surface oxide layer formation and spallation. The focus of study was in determining the complex interactions between alloying elements in steel matrix and oxidation environment, composition and surface morphology of formed oxides. This report will also explore how the …

A Guide To Fifty Years Of Research At Montana Tech: Part 3-Decontamination Of Ratioactively Contaminated Steel By Melt Refining/Slagging Processing, Larry G. Twidwell, Samuel A. Worcester

Metallurgy

This presentation includes a discussion of the research conducted at Montana Tech in the Department of Metallurgical and Materials Engineering. The discussion is focused on Decontamination of Radioactively Contaminated Steel by Melt Refining/Slagging. This presentation is based on the research of Master of Science graduate students, industrial and academic colleagues, at the Montana College of Mineral Science and Technology (which morphed to Montana Tech [1977], then to Montana Tech of The University of Montana [2000], then to Montana Technological University [2019]). The referenced work of each of the graduate students in this presentation is gratefully acknowledged. The following summary presentation …

Segregation And Heat Treatment Response Of Cast Quench And Partition Steels, Mujeeb Hussain Shaik

Masters Theses

Quench and partition (Q&P) steels have emerged as promising alternatives to traditional quenching and tempering methods, offering a superior balance of strength and ductility due to their unique microstructure of martensite, and retained austenite. This literature review examines the development and optimization of Q&P steels, focusing on their mechanical properties, heat treatment processes, and applications in various industries. This study explores the application and effectiveness of the Quench and Partition (Q&P) heat treatment process on cast steels and examines segregation phenomena in cast medium Mn steels. Medium Mn steels were employed for various Q&P cycles on cast specimens to investigate …

The Behavior Of ½⟨111⟩ Screw Dislocations In W–Mo Alloys Analyzed Through Atomistic Simulations, Lucas A. Heaton, Kevin Chu, Adib J. Samin

Faculty Publications

Analyzing plastic flow in refractory alloys is relevant to many different commercial and technological applications. In this study, screw dislocation statics and dynamics were studied for various compositions of the body-centered cubic binary alloy tungsten–molybdenum (W–Mo). The core structure did not appear to change for different alloy compositions, consistent with the literature. The pure tungsten and pure molybdenum samples had the lowest plastic flow, while the highest dislocation velocities were observed for equiatomic, W_0.5Mo_0.5 alloys. In general, dislocation velocities were found to largely align with a well-established dislocation mobility phenomenological model supporting two discrete dislocation mobility regimes, …

Inhibited Surface Diffusion In Nanoporous Multi-Principal Element Alloy Thin Films Prepared By Vacuum Thermal Dealloying, Tibra Das Gupta, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Nanoporous structures with 3D interconnected networks are traditionally made by dealloy- ing a binary precursor. Certain approaches for fabricating these materials have been applied to refrac- tory multi-principal element alloys (RMPEAs), which can be suitable candidates for high-temperature applications. In this study, nanoporous refractory multi-principal element alloys (np-RMPEAs) were fabricated from magnesium-based thin films (VMoNbTaMg) that had been prepared by magnetron sputtering. Vacuum thermal dealloying (VTD), which involves sublimation of a higher vapor pres- sure element, is a novel technique for synthesizing nanoporous refractory elements that are prone to oxidation. When VMoNbTaMg was heated under vacuum, a nanoporous structure was …

Synthesis Of Ni-Based Intermetallics By Electrolytic Plasma Processing Of Ti And Ti-Based Alloys, Chuzhong Zhang

Material Science and Engineering Dissertations - Archive

EPP is an innovative surface modification technique that enables the deposition of metal ions from the electrolyte and their integration with substrate atoms to form intermetallic compound surface layers. EPP offers advantages such as high deposition rates, environmental cleanliness, and operational simplicity. In this study, Ni-Ti intermetallic layers were successfully synthesized on a Ti-6Al-4V substrate using EPP. The properties of the resulting Ni-Ti intermetallic layers were characterized using SEM, EDS, XRD, TEM, nanoindentation, and tribology tests.

This work aims to understand the fabrication mechanism and investigate the effects of various processing parameters on the EPP process. Key factors such as …

Quantitative Modeling Of Micro Discharge And Oxide Growth In Plasma Electrolytic Oxidation Of Titanium, Kingsley I. Ochiabuto

Material Science and Engineering Dissertations - Archive

Plasma electrolytic oxidation (PEO) has been extensively applied in the past to improve the tribological properties of titanium and its alloys allowing their widespread use in industrial applications. However, the complete PEO mechanism of action remains unclear. While there are several mathematical models providing useful insights into the PEO process, they do not fully incorporate the effect of applied potential on the outcomes of PEO. In this work, we develop an experimentally informed computational model by expanding on the dielectric breakdown model. We incorporate experimental data to extract key parameters, exploring the iterative dependency of the oxide thickness and ionic …

Ijmc/Fef Student Research Competition: Understanding The Effect Of Boron On Graphite Nodularity And Distribution In Ductile Iron Castings, Chase Schroeder, Colleen Lehrer, Simon Lekakh, Laura Bartlett

Materials Science and Engineering Faculty Research & Creative Works

Ductile iron is renowned for its superior mechanical properties, higher strength, and ductility, combined with excellent castability and the economy of using a scrap melting process. The matrix structure as well as morphology and distribution of graphite nodules significantly influences mechanical properties of as-cast ductile iron. Boron contamination of the scrap supply has presented some difficulties in controlling the microstructure and mechanical properties of certain gray and ductile iron grades. In the current study, the effect of boron levels up to 95 ppm was determined on graphite nodularity and distribution in as-cast ductile iron castings as a function of section …

Damage Initiation Of 15v38 Steel Bar During Square-To-Round Hot Rolling Process, Siva Sai Krishna Dasari, Henry Adekola Haffner, K. Chandrashekhara, Mario F. Buchley, Simon N. Lekakh, Ronald J. O'Malley

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Hot rolling processes have been extensively used to produce round bars by reducing the cross-sectional area of continuously cast steel. The current trend toward increasing productivity often requires a more aggressive reduction per pass. Establishing safe and optimized hot rolling parameters must be determined to avoid damage while deforming the specific steel composition. Understanding the damage mechanism during the metal forming process is vital for product quality. Herein, a combined experimental and simulation approach is developed to track the evolution potential damage during hot bar rolling. Hot tension tests are conducted on as-cast vanadium micro alloyed 15V38 steel at different …

Solidification Cracking In Additively Manufactured High Entropy Alloy Nicrcofe With V Or W, Andrew R. Walch

Dissertations, Master's Theses and Master's Reports

Recent sustainability efforts have reduced CO2 emissions from electricity generation by increasing operating temperatures and pressures in advanced ultra-supercritical (A-USC) power plants. However, the extreme operating conditions in these A-USC power plants require new high temperature materials. The recent study of nickel-based high-entropy alloys (HEA) represents the latest approach to meet the specifications for A-USC operations. A CALculation PHase Diagram (CALPHAD) driven Bayesian optimization method was used to design the composition of alloys composed of NiCrCoFe with V or W, which were fabricated via wire-based additive manufacturing to enable high throughput development. Although the alloy was designed to minimize solidification …

ผลกระทบของการอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤตต่อโครงสร้างจุลภาค และคุณสมบัติทางกลของเหล็กกล้าดูอัลเฟส, วิชยุตม์ ชูเมือง

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในการศึกษานี้ ได้มีการประยุกต์การอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤตเพื่อปรับเปลี่ยนสมบัติทางกลของเหล็กกล้าดูอัลเฟสที่มีส่วนผสม 0.107%C-2.39%Mn-0.453%Si ผลการอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤต (IC2) ถูกตรวจสอบโดยการสังเกตโครงสร้างจุลภาค การทดสอบแรงดึงและการทดสอบความแข็งแบบวิกเกอร์ แล้วจึงเปรียบเทียบผลกับชิ้นงานที่อบอ่อนระหว่างอุณหภูมิวิกฤตครั้งเดียว (IC1) โดยพบว่าการเพิ่มอุณหภูมิการอบอ่อนระหว่างอุณหภูมิวิกฤตส่งผลให้ความเค้นคราก ความต้านทานแรงดึง และความแข็งเพิ่มขึ้นในขณะที่ความเหนียวลดลงเนื่องจากการเพิ่มขึ้นของปริมาณมาร์เทนไซต์เป็นหลัก หลังจาก IC2 ส่งผลให้ชิ้นงานมีขนาดเกรนเฟร์ไรต์และปริมาณมาร์เทนไซต์ลดลงเล็กน้อย และจากผลการทดสอบแรงดึงพบว่า IC2 สามารถเพิ่มความเหนียวโดยไม่ส่งผลให้ความแข็งแรงลดลงอย่างมีนัยสำคัญ จากผลลัพธ์ที่ได้บ่งบอกว่าสามารถใช้วิธีการอบอ่อนซ้ำระหว่างอุณหภูมิวิกฤต เพื่อปรับปรุงคุณสมบัติทางกลของเหล็กกล้าดูอัลเฟสได้ โดยไม่เพิ่มความซับซ้อนให้กับกระบวนการผลิตมากเกินไป

The Characterization And Nanomechanical Properties Of Microstructurally Complex Systems, Kerry Ann Baker

Theses and Dissertations--Chemical and Materials Engineering

Since the dawn of civilization, the use of metals has played an integral role in the evolution of human society. Over the years, and with the introduction of new engineering and science, we have learned how to combine metals to create new metallic systems. We have expanded our understanding of dealloying and chemical reactions, and, in doing so, we created nanoporous metals. Our use of metals has evolved from basic alloys such as bronze and steel to more complex alloys such as multi-principal element alloys. Nanoporous gold is an advanced metallic system that can be created through the dealloying process. …

Advancing Combinatorial Screening Of Refractory High Entropy Alloys Through Intrinsic Ductility Assessment Via Thin Film Fragmentation Testing, Taohid Bin Nur Tuhser

Theses and Dissertations--Chemical and Materials Engineering

High Entropy Alloys (HEAs), also known as Multiprincipal Element Alloys (MPEAs), represent a paradigm shift in alloy design. Unlike traditional practices that limit compositions to the edges of phase diagrams, HEAs exploit equiatomic mixing of five or more elements at the center of phase diagrams to maximize configurational entropy. This unconventional approach exponentially expands the spectrum of potential alloy compositions, rendering conventional experimental methods inadequate for exploring this extensive compositional space.

In response to these challenges, the scientific community has shown a growing interest in high-throughput techniques, encompassing both computational and experimental domains. Particularly, Refractory High Entropy Alloys (RHEAs) have …

Microstructural Investigation Of The Influence Of Geometry On The Mechanical Reliability Of Additively Manufactured Metals, Tracy Connor Varney

Theses and Dissertations--Chemical and Materials Engineering

The adoption of additive manufacturing across a wide range of fields is ever-increasing, allowing for solutions that were previously impossible to achieve. This dissertation demonstrates the wide range of macro- and micro- characterization techniques used to investigate several precipitation strengthened AM alloy systems. While AM allows for nearly unlimited design freedom, this brings along its own issues as the interplay between scan strategy and part geometry is less well known. In this work, a novel thin-wall dogbone geometry was utilized to study one type of complex geometry observed in a large portion of AM focused designs. The mechanical behavior of …

Inherently Porous Metal Structures With Sufficient Mechanical Properties Through Direct Writing Of Bio-Based Inks, Havva Eda Aysal

Graduate Theses, Dissertations, and Problem Reports (ETD)

There is currently a burgeoning interest in developing 3D printed metal structures with inherent porosity and sufficient mechanical properties for mass customization in the biomedical field. Current approaches for 3D printing of biocompatible metals rely on powder-bed fusion methods which are energy intensive and utilize large amounts of metal powder that is challenging to recycle. In addition, such methods aim on producing dense parts and porosity generation, within the printed part, is challenging due to the complex physics of the melting pool. Here, a relatively new and promising approach is undertaken to study the 3D printing of inherently porous structures …

Theoretical Modeling And Experimental Investigation Of Phase Selection During Rapid Solidification Of Alloys, Azeez Aremu Akinbo

Masters Theses

"A novel model, rooted in time-dependent nucleation theory, has been created to explore how rapid solidification affects the extended solubility in metal alloys. This model was used to forecast solubility concerning undercooling in multiple binary aluminum (Al) alloys, and its predictions for both eutectic and peritectic systems closely match experimental data. It was demonstrated that this developed model surpasses the T0 line method, which does not consider the kinetic aspects of nucleation. Furthermore, the model can be extended to ternary and multicomponent phases by assuming that the scarcest element or the slowest diffusing component restricts nucleation. Al-Cu and Al-Cr, vital …

F-Temper Vs O-Temper Brazing Of 3003 Aluminum Return Bends, Mieka R. Clark

Dissertations, Master's Theses and Master's Reports

As-extruded (F-temper) 3003 return bends can provide cost savings over annealed (O-temper) return bends in aluminum heat exchangers. To assess if F-temper return bends are an alternative to the baseline O-temper bends, the grain structure, bending performance, and melting behavior were assessed through:

• Quantifying the effect of dispersoids on recrystallization
• Tracking bending behavior through grain morphology and surface texture
• Measuring the number and volume fraction of the α-Al(Mn,Fe)Si intermetallic
• Inducing incipient melting through high temperature thermal exposure.

When homogenized at 620°C and 630°C, the F-temper bends had no orange peel texture, the grain size was equivalent to the annealed product, …

Improving Cast Steel Rail Coupler Fatigue Resistance Through Local Wire-Arc Additive Manufacturing, Andrew M. Bunge

Dissertations, Master's Theses and Master's Reports

Every year, thousands of cast-steel railcar couplers suffer from corrosion-initiated fatigue cracking in similar areas of the coupler’s knuckle; between 2015 and 2018 about 90,000 knuckles were replaced, otherwise these couplers would have been at risk for unexpected failures. These types of couplers have been common in industrial use as early as 1932, hence it is desirable for a countermeasure to the fatigue cracking that does not involve significantly altering the geometry or casting process. Wire arc additive manufacturing (WAM) is a developing technology which boasts the ability to produce complex near-net-shape components; however, less attention has been paid to …

High Temperature Strength Reduces Soldering In Aluminum High Pressure Die Casting, Jacob A. Belke

Dissertations, Master's Theses and Master's Reports

Die soldering, an adhesion defect in high pressure die casting (HPDC), is a symptom of localized sticking where a localized portion of the cast material is adhered to the tooling surface causing build up over time. This requires the tooling to be serviced which incurs additional costs to the process that gets passed on to the parts. Historically, soldering has been mitigated using lubricants, coatings, and alloy chemistry modifications but solder persists.

The Tresca friction thermomechanical model suggests soldering occurs when the local interfacial shear stress between the casting and die surface exceeds the local shear strength of the casting. …

Parametric Optimization Of Friction Stir Welding Of Aa6061-T6 Samples Using The Copper Donor Stir-Assisted Material Method, Aiman H. Al-Allaq, Joseph Maniscalco, Srinivasa Naik Bhukya, Zhenhua Wu, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

This study presents an optimization of the process parameters for the effect of copper (Cu) donor material percentage on the friction stir welding (FSW) of AA6061-T6 alloy. Extensive factorial experiments were conducted to determine the significance of the rotational speed (ω), the transverse speed (v), the interface coefficient of friction (μ), and the Cu donor material percentage in the plunge, left, right, and downstream zones. Design Expert 13 software was used to identify the number of simulation experiments to be conducted using the Abaqus simulation software. From Design Expert 13, which is a thorough multi-objective optimization analysis software, we were …

A Review On Biochar As An Adsorbent For Pb(Ii) Removal From Water, Pushpita Kumkum, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

Heavy metal contamination in drinking water is a growing concern due to its severe health effects on humans. Among the many metals, lead (Pb), which is a toxic and harmful element, has the most widespread global distribution. Pb pollution is a major problem of water pollution in developing countries and nations. The most common sources of lead in drinking water are lead pipes, faucets, and plumbing fixtures. Adsorption is the most efficient method for metal removal, and activated carbon has been used widely in many applications as an effective adsorbent, but its high production costs have created the necessity for …

Mechanisms Of Dendritic Shorting In Lithium Metal Batteries With Li7la3zr2o12 Solid Electrolytes, Lukas Karapin-Springorum

Pomona Senior Theses

Energy storage will play a crucial role in efforts to mitigate the effects of climate change caused by greenhouse gas emissions from human activity. Lithium metal batteries using solid electrolytes like Li₇La₃Zr₂O₁₂ have higher energy density than lithium-ion batteries, which may enable a more rapid and complete electrification of transportation. However, lithium metal batteries suffer from undesirable short-circuiting when metallic lithium deposits connect the two electrodes. It has been debated whether these lithium dendrites generally grow directionally from the anode or are generated by the reduction of lithium ions inside the solid electrolyte, …

B(C₆F₅)₃ Co-Catalyst Promotes Unconventional Halide Abstraction From Grubbs I To Enhance Reactivity And Limit Decomposition, Austin W. Medley, Diya Patel, Calvin Utne, Trandon A. Bender

Chemistry & Biochemistry Faculty Publications

Ruthenium based Grubbs metathesis has become a commonplace reaction for synthetic chemists. Development of new generations of catalysts evolving from Grubbs I (GI) have led to greater stability, functional group compatibility, and superior reactivities. However, these advancements lead to increased costs. To this end, we report here how the addition of the commercially available tris(pentafluorophenyl)borane Lewis acid, which has become a common place catalyst in its own right, leads to enhanced reactivity of GI. Moreover, the increased reactivity arises via halide abstraction rather than traditional phosphine dissociation, providing ring-opening metathesis polymerization products that are divergent from those synthesized without the …

Calculation Of Elastic Constants Of Bulk Metallic Glasses From Indentation Tests, Zhitong Xu, Ming Liu, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

One of the challenges in the applications of instrumented indentation is to simultaneously measure elastic modulus and Poisson’s ratio of homogeneous, isotropic materials. This work proposes empirical equations for simultaneous calculation of elastic modulus and Poisson’s ratio of bulk metallic glasses (BMGs) from the ratio of the short diagonal length to the long diagonal length and the area of the Knoop imprint. The parameters pre- sented in the empirical equations are determined first by Knoop microhardness tests of 24 BMGs, whose elastic moduli and Poisson’s ratios are measured by resonant ultrasound spectroscopy. These empirical equations are further validated by the …

Impact Of Quenching Intensity Conditions On Using A Finite Element Model To Investigate The Microstructure And Hardenability Of Low-Alloy Steel, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

Quenching is one of the primary processes to improve mechanical properties in steels, particularly hardness. Quenching is well established for different geometries of individually treated steel components; while in-steam quenching of large diameter continuously cast steel bar has several specific features which are difficult and costly to experimentally optimize. The end-quench Jominy test has been used extensively to study the hardenability of different steel grades. Different numerical, analytical, and empirical models have been developed to simulate the Jominy process and to understand quenching of steels. However, it is not straight forward to translate experimental data from Jominy test on instream …

Impact Of Quenching Intensity Conditions On Using A Finite Element Model To Investigate The Microstructure And Hardenability Of Low-Alloy Steel, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

Quenching is one of the primary processes to improve mechanical properties in steels, particularly hardness. Quenching is well established for different geometries of individually treated steel components; while in-steam quenching of large diameter continuously cast steel bar has several specific features which are difficult and costly to experimentally optimize. the end-quench Jominy test has been used extensively to study the hardenability of different steel grades. Different numerical, analytical, and empirical models have been developed to simulate the Jominy process and to understand quenching of steels. However, it is not straight forward to translate experimental data from Jominy test on instream …

Effects Of Ac Interference On Pipelines Under Cathodic Protection And Cathodic Disbondment Of Pipeline Coatings, Tanner Laughorn

Williams Honors College, Honors Research Projects

This project is split into two parts. The first revolves around AC interference on pipeline steel under cathodic protection. The corrosion rate of steel samples will be measured after they are exposed to varying levels of AC interference and cathodic protection. The results will be used to help develop new guidelines for appropriate cathodic protection of steel pipelines. The second part of this project revolves around the cathodic disbondment of pipeline coatings while under cathodic protection. The disbondment distance, electrolyte pH, and electrochemical impedance spectroscopy will be tested for multiple industry standard coatings under various conditions. The results will be …

Causational Analysis And Rectification Of Issues Concerning Scale Formation On Hot-Rolled Straight Bar Product And Its Effects On Ultrasonic Testing, Riley Mattix

Williams Honors College, Honors Research Projects

At Charter Steel's NDT Processing Plant located in Cleveland, Ohio, a concern has arisen regarding the recently implemented bar straightening and UT (Ultrasonic Testing) equipment. A substantial amount of mill scale, which is typically removed during the straightening process, is persisting on the bar’s surface throughout most of the NDT procedure. This lingering scale has been observed to flake off once inside the UT equipment, introducing unwanted noise and phantom peaks into the UT readings. Additionally, thick mill scale has been identified as a source of background interference in the received data. In contrast, bars that have been subjected to …