Digital Commons Network^™

Surface Alloying Of Mild Steel During Casting Process: Microstructural Evolution, Phase Development And Heat Treatment, Kaustubh Kishore Rane

Theses and Dissertations

Casting is one of the oldest manufacturing processes in practice and the growth of casting industry through the ages has led to scientific leaps in the field of metallurgy. As we look into the history of metal castings, it is prominent that a steady growth in the knowledge leading to rise of newer casting techniques has caused an exponential increase in the way we can use metal castings to improve our lives. The surface alloying of mild steel to compositions targeted towards stainless steel compositions was performed in this study by sand casting process. Sand casting is one of the …

Application Of Survival Analysis Techniques To Probabilistic Assessment Of Fatigue In Steel Bridges, Azam Nabizadehdarabi

Theses and Dissertations

The fatigue of engineering materials under repetitive loading is a significant issue affecting the design and durability of components and systems in a variety of engineering-related applications including civil, mechanical, aerospace, automotive, and electronics. Many factors can affect the service life of a component or system under repetitive loading, such as the type of structure, loading, connection details, stress state, peak stress or stress range, surface condition, temperature, and environmental exposure. Currently, there is no comprehensive probabilistic approach that can systematically address all the factors that contribute to fatigue on a single mathematical platform. However, advanced analysis techniques developed for …

The Effect Of Rapid Solidification And Heat Treatment On Microstructure And Electrochemical Properties Of Advanced Biomaterial Co-Cr-Mo-C Alloy, Hamid Reza Erfanian Nazif Toosi

Theses and Dissertations

Co-Cr-Mo-C alloys have been used for implant materials for decades because of their strength, corrosion resistance, wear resistance, and biocompatibility. To develop durable low-friction joint replacement implants, it is important to understand the solidification structure and properties of these materials. While HCP phase is the thermodynamically stable phase in these alloys, they maintain their high-temperature γ-FCC matrix and coarse dendritic structure on cooling to room temperature when cast by conventional methods. In this research, a wedgeshaped copper chill mold was used to examine the effect of cooling rates from 10 K/s to 450 K/s on the microstructure, HCP fraction, and …

Optimizing Self-Healing Wind Turbine Blades Utilizing Dicyclopentadiene Infused Vascular Networks, Giovanni Lewinski

Theses and Dissertations

Self-healing wind turbine blades can reduce costs associated with maintenance, repair, and energy compensation. Self-healing is the ability to sustain and recover from damage autonomously. The self-healing presented in this paper uses the reaction of two agents Dicyclopentadiene, DCPD, and Grubbs’ first-generation catalyst, henceforward known as a catalyst to fuel this recovery. DCPD is housed as a liquid isolated from the catalyst until a damaging event occurs, causing the two agents to mix and solidify to form the thermoset Polydicyclopentadiene, PDCPD. We discuss the efforts made to optimize the self-healing properties of wind turbine blades and provide new systems to …

Development Of Investment Casting Method For Production Of Metal Foams For Tissue Engineering, Justin Aaron Womack

Theses and Dissertations

Ideal biomaterials for bone tissue regeneration are bone-mimicking structures that present a fully interconnected porous structure, have similar mechanical properties to bone, and exhibits a specific biodegradation behavior that is at the same rate as adjoining cell growth. Metals have high wear resistance, ductility, impact strength, and strain energy absorption capacity compared to other materials, which makes them suitable candidates for tissue engineering scaffolds. Magnesium and zinc are of interest for bone tissue regeneration for their biocompatibility and mechanical properties close to human bone. A newly developed process, presented in this thesis, for the creation of porous magnesium and zinc …

In Situ Chemical Probing Of Vacancy Defects In Graphene And Boron Nitride At Room Temperature, Ali Ihsan Altan

Theses and Dissertations

IN SITU CHEMICAL PROBING OF VACANCY DEFECTS IN GRAPHENE AND BORON NITRIDE AT ROOM TEMPERATURE

by

Ali Ihsan Altan

The University of Wisconsin-Milwaukee, 2019

Under the Supervision of Professor Jian Chen

Chemical vapor deposition (CVD) has emerged as the most promising technique towards manufacturing of large area, high quality graphene. Characterization, understanding, and controlling of various structural defects in CVD-grown graphene are essential to realize its true potential for real-world applications. We report a new method for in situ chemical probing of vacancy defects in CVD-grown graphene at room temperature. Our approach is based on a solid–gas phase reaction that …

Using Pythagorean Fuzzy Sets (Pfs) In Multiple Criteria Group Decision Making (Mcgdm) Methods For Engineering Materials Selection Applications, Alaa Fouad Momena

Theses and Dissertations

The process of materials’ selection is very critical during the initial stages of designing manufactured products. Inefficient decision-making outcomes in the material selection process could result in poor quality of products and unnecessary costs. In the last century, numerous materials have been developed for manufacturing mechanical components in different industries. Many of these new materials are similar in their properties and performances, thus creating great challenges for designers and engineers to make accurate selections. Our main objective in this work is to assist decision makers (DMs) within the manufacturing field to evaluate materials alternatives and to select the best alternative …

The Effective Use Of Portland Cement In Reactive Powder Hybrid Asphalt Concrete, Clayton Cloutier

Theses and Dissertations

Today, building a durable and cost-efficient infrastructure while minimizing future repair needs is a challenging task, and innovative technological breakthroughs are needed. Limited research has been conducted to investigate the use of portland cement (PC) to improve the performance of asphalt pavements. Portland cement in bitumen materials is attractive as it can improve the performance and reduce costs. Warm Mix Asphalt (WMA) is also an attractive alternative to Hot Mix Asphalt (HMA) as this material produces tremendous energy savings by lowering the production temperatures and enhances certain performance characteristics. It can be envisioned that the use of portland cement incorporated …

In Situ Chemical Probing Of Vacancy Defects In Graphene And Boron Nitride At Room Temperature, Ali Ihsan Altan

Theses and Dissertations

IN SITU CHEMICAL PROBING OF VACANCY DEFECTS IN GRAPHENE AND BORON NITRIDE AT ROOM TEMPERATURE

by

Ali Ihsan Altan

The University of Wisconsin-Milwaukee, 2019

Under the Supervision of Professor Jian Chen

Chemical vapor deposition (CVD) has emerged as the most promising technique towards manufacturing of large area, high quality graphene. Characterization, understanding, and controlling of various structural defects in CVD-grown graphene are essential to realize its true potential for real-world applications. We report a new method for in situ chemical probing of vacancy defects in CVD-grown graphene at room temperature. Our approach is based on a solid–gas phase reaction that …

Active Polymeric Materials For 3d Shaping And Sensing, Adebola Oyefusi

Theses and Dissertations

Part I: Reprogrammable Chemical 3D Shaping for Origami, Kirigami, and Reconfigurable Molding

Origami- and kirigami-based design principles have recently received strong interest from the scientific and engineering communities because they offer fresh approaches to engineering of structural hierarchy and adaptive functions in materials, which could lead to many promising applications. Herein, we present a reprogrammable 3D chemical shaping strategy for creating a wide variety of stable complex origami and kirigami structures autonomously. This strategy relies on a reverse patterning method that encodes prescribed 3D geometric information as a spatial pattern of the unlocked phase (dispersed phase) in the locked phase …