Manufacturing Commons^™

Effect Of Wall Movement On Porosity Formation In Ductile Iron Castings Under Varying Processing Parameters, Shamsul Alam

College of Graduate Studies: Theses & Dissertations

Shrinkage porosity is a major defect that significantly impairs the mechanical properties and overall performance of ductile iron castings. Although graphite formation during solidification induces volumetric expansion, this expansion alone is insufficient to fully compensate for the shrinkage occurring throughout solidification. During the solidification and cooling of ductile iron, multiple phase transformations occur, resulting in dynamic volume changes that exert pressure on mold walls and internal cavities. These pressures can deform mold walls and casting surfaces, leading to defects such as swell and porosity, while also influencing shrinkage formation. This study aims to analyze the mechanisms of porosity formation and …

Ease Of Product Disassembly Through A Systematic Structured Time-Based Design For Disassembly Methodology, Emeka S. Igwe

College of Graduate Studies: Theses & Dissertations

This research introduces a systematic time-based design for disassembly (DfD) framework aimed at optimizing product disassembly by addressing important features like liaisons between components in product, component accessibility and the overall modularity of the product. This study specifically covers electromechanical and mechatronic systems in both household and industrial setup, identifying their disassembly challenges and high value pointers for improvement. The methodology involves using a design for disassembly framework called LeanDfD in carrying out a holistic disassembly process and evaluating quantitative metrics like disassembly time and complexity and suggesting further redesign strategies to minimize disassembly time and cost. Adopting this systematic …

Ranking Of Non-Destructive Testing Methods For Ductile Iron Castings For Industry 4.0, Michael W. Jones

College of Graduate Studies: Theses & Dissertations

Non-destructive testing techniques provide a unique solution to provide quality assurance of parts rapidly and efficiently without altering the functional properties of the workpiece. The metal casting industry requires an elevated level of quality assurance, as castings are critical components to several industries. The wrong selection of non-destructive testing methods could increase production costs, quality costs, and potentially permit non-conforming castings to enter the market. The aim of this research is to develop a ranking model for non-destructive testing techniques for ductile iron castings within the context of the fourth industrial revolution. The ranking model analyzes the effectiveness of the …

Pulsed Arc Additive Manufacturing Of A Functionally Graded Er2209 Duplex Stainless Steel And Hsla-100 Structure: Morphology, Characterization, And Mechanical Performance, Stevens G. Hill Jr

College of Graduate Studies: Theses & Dissertations

Wire arc additive manufacturing is a process well suited to the efficient production of large structures. Duplex stainless steel exhibits high corrosion resistance and good strength which can be highly beneficial for industrial use. However, its use is limited due to its cost and complexity in controlling microstructure to achieve desired properties. In many cases, it can be highly beneficial to manufacture a component which uses specialty steel grades such as duplex stainless steel only where necessary, and utilizes more affordable, commonly available steels for reinforcement or bulk structural support. A functionally graded material satisfies these requirements by providing a …

Effect Of Alloying Additions On Austenite Refinement In Nickel-Alloyed Ductile Cast Irons, Adnan Adib Aahamed

College of Graduate Studies: Theses & Dissertations

The benefits associated with the application of ductile irons are significantly attributed to the control of microstructures, with refinement of austenitic matrix during solidification playing a significant role. Nickel alloyed ductile irons are attractive due to their potential for high ductility and suitability for potential high-temperature applications with stable austenitic microstructure. Refinement of austenite grain structure is thus important to enhance the mechanical properties of the alloyed ductile iron. This research investigates the impact of in-mold additions of different alloying elements on the austenite morphology and grain refinement of nickel-alloyed ductile iron along with the associated mechanical properties. A hypoeutectic …

Enhancing The Mechanical Properties Of Sla 3d-Printed Bio-Resin From Linseed Oil Using Cellulose And Lignin Biopolymers, Chukwunonso A. Ikedionu

College of Graduate Studies: Theses & Dissertations

Abstract

This research explores the development of bio resin from linseed oil by the process of epoxidation and acrylation to produce acrylated epoxidized linseed oil (AELO). Lignin and cellulose biopolymers were added as reinforcement at varying weight fractions of 1 wt.%, 2.5 wt.%, and 5 wt.%, and their mechanical performance was compared against pure AELO. The formulations were printed using an Elegoo SLA 3D printer to create standardized test specimens like tensile bars, compression cylinders, and hardness blocks, which were all prepared according to the ASTM testing standard.

The results indicate that reinforcement effects depend on both filler type and …

Resonant Ultrasound Spectroscopy(Rus) For Material Characterization Of Metal Am Parts, Malik Marks

College of Graduate Studies: Theses & Dissertations

Additive manufacturing (AM) has revolutionized the manufacturing industry by offering flexibility, customization, and rapid prototyping capabilities. However, ensuring the quality and reliability of AM parts remains a significant challenge due to variations in material properties and process parameters. The NDE method used in this study is Resonant Ultrasound Spectroscopy (RUS). This method was used to evaluate and understand its ability to detect internal voids and defects. Dog-bone samples were made using the 316L stainless steel alloy which were fabricated by powder bed fusion (PBF) AM technique at different processing conditions and post processing conditions. These samples were tested to find …

Understanding The Impact Of Process Interruption On Mechanical Properties In Metal Additive Manufacturing: A Comprehensive Investigation, Poojith C. Chigurupati

College of Graduate Studies: Theses & Dissertations

Metal additive manufacturing techniques enable rapid prototyping and on-demand manufacturing while improving supply chain resiliency. Changes in microstructure and micro-mechanical characteristics of 3D printed metal parts occur due to the influence of process interruptions on melting-solidification cycles during the layer evolution in additive manufacturing processes. The process interruption can deteriorate the structural integrity of the 3D printed parts and generate micro-flaws in the interruption region. Manufacturing post-processing techniques such as Heat-Treatment methods can enhance the mechanical properties of the parts. Since variations commonly happen at the layer level, the investigation of mechanical properties must be done such that these variations …

Development And Characterization Of Vegetable Oil Based, Acrylated Resins For Stereolithography 3d Printing, Julius A. Adeyera

College of Graduate Studies: Theses & Dissertations

The increase in the demand for additively manufactured parts and the drive towards a sustainable economy with less environmental pollution has necessitated the need for renewable materials for use in 3D printing. This study shows the development and characterization of vegetable oil based, acrylated resins for 3D printing. Bio-based 3D resins were formulated using bio-based oils with a minimum of 70% bio-based content and were ready to be polymerized using the stereolithography (SLA) 3D printing process. Two distinct vegetable oils were used to develop biobased photopolymers. Biobased acrylated epoxidized photopolymers were successfully developed that have good mechanical and chemical properties. …

Experimental Investigation Of Liquid Metal Embrittlement In Hot-Dip Galvanized Structural Steel, Amelia Mcnamee

College of Graduate Studies: Theses & Dissertations

This research investigated the liquid metal embrittlement (LME) of hot-dipped galvanized structural steel. The relationship between stress and failure time was analyzed to evaluate the potential presence of a critical stress threshold beyond which LME may occur. A testing apparatus to induce axial stress was designed and assembled in-house. A36 low carbon steel was tested in this study. Different deadweight loadings were applied to the testing sample along the axial direction. The test temperature was maintained by a programmable furnace while the sample gauge section was submerged in a molten zinc bath. Failure time and total displacement of the steel …

Investigation Of Manufacturing Techniques For Magnetorheological Elastomers To Expand Feasibility In A Diverse Array Of Applications, Austin S. Robbins

College of Graduate Studies: Theses & Dissertations

Magnetorheological elastomers, or MREs, are smart composite materials with controllable physical and mechanical properties when introduced to an external stimulus of a magnetic field. The controllability of these properties is highly tunable by the selection of the elastomeric matrix, concentration of magnetically permeable particles, introduction of additives, and the alignment of the constituents during the curing process. The fabrication of MREs typically calls for a mold that is filled with an MRE mixture to create the final desired geometry after curing. These molds are frequently placed under a magnetic field which orients the micron sized magnetic particles along the magnetic …

An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez

College of Graduate Studies: Theses & Dissertations

Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …

Design And Fabrication Of A Force-Displacement Control Mechanism For Bone-Surgical Tool Testing, Kenneth Nwagu

College of Graduate Studies: Theses & Dissertations

This project focuses on the design and fabrication of an experimental setup for orthopedic-tool testing, tailored for a surgical instrumentation company. The multifaceted project encompasses a literature review, conceptual design, prototyping, and rigorous testing, resulting in a versatile control system capable of assessing various orthopedic tools, including bone drills, saws, burrs, and power handpieces.

Orthopedic surgical procedures (which include cutting and/or drilling into bone) often need to be performed on bones for faster recovery. The drilling and cutting process can cause an increase in temperature at the cutting site which can cause bone necrosis. The tools also need to be …

A Study Of Reduced Activation Ferritic Martensitic Metal Core Wire For Wire Arc Additive Manufacturing, Alexander L. Reichenbach

College of Graduate Studies: Theses & Dissertations

This study seeks to determine the technical feasibility of fabricating reduced activation ferritic martensitic (RAFM) steel parts, using a wire arc additive manufacturing (WAAM) process. The WAAM process, manufactures a part by depositing layers of metal onto a substrate to build a large scale near net shape part. RAFM alloy steels are next generation steels designed to resist radiation effects in the radiation intense working environments, such as nuclear reactors. To achieve this, process development and testing to design the WAAM production process with the custom RAFM filler wire was carried out. Several welding waveform modes were tested, and it …

Effects Of Titanium And Cerium Addition On Grain Size And Mechanical Properties Of Ductile Iron Castings, Shelton F. Fowler Iv

College of Graduate Studies: Theses & Dissertations

According to the Hall-Petch equation, the refinement of grains in metals increases the yield strength of the material. Austenite grain size influences the fineness of microstructural constituents in the ferrous alloys. It is well studied that cerium and titanium refine the austenite in steels and some gray irons, but no studies have been done to systematically explore the effects of cerium and titanium additions on austenite in ductile iron. This study sought to determine the effects of selected levels of these elements on the grain size within ductile iron. A hypoeutectic iron was chosen for testing as the proeutectic phase …

Mechanical Properties Of Nanomodified Hybrid Gfrp Composite Materials, Micah Rop Kimutai

College of Graduate Studies: Theses & Dissertations

The mechanical behavior of the nanomodified hybrid epoxy matrix was investigated in glass fiber reinforced plastics (GFRP). In this study, five nanocomposites enriched with as received halloysite, nanomer I.28E, HNT-APTES, and the hybrid combinations of the two HNTs with the nanomer I.28E were successfully fabricated. To evaluate the effects and morphological characteristics of the individual fillers and the hybrid configurations on the epoxy resin matrix, TGA, DSC, and DMA were analyzed. To understand the effect of the five configurations on the neat GFRP laminate, mode I interlaminar fracture toughness, tensile, and vibration properties were investigated. Electron microscopy testing techniques were …

In-Situ Process Monitoring For Metal Additive Manufacturing (Am) Through Acoustic Technique, Md Shahjahan Hossain

College of Graduate Studies: Theses & Dissertations

Additive Manufacturing (AM) is currently a widely used technology in different industries such as aerospace, medical, and consumer products. Previously it was mainly used for prototyping of the products, but now it is equally valuable for commercial product manufacturing. More profound understanding is still needed to track and identify defects during the AM process to ensure higher quality products with less material waste. Nondestructive testing becomes an essential form of testing for AM parts, where AE is one of the most used methods for in situ process monitoring. The Acoustic Emission (AE) approach has gained a reputation in nondestructive testing …

The Development Of A Holistic Quality Score Using In-Situ Monitoring Of Laser Powder Bed Fusion, Ryan Daigneault

College of Graduate Studies: Theses & Dissertations

Additive manufacturing processes allow for a great degree of flexibility in terms of part production. The process is autonomous once the part has started printing in that the operator generally does not need to intervene until the part is finished. One issue that this introduces, however, is an inability to determine part quality during the printing process. Once a part has started printing, the operator must either wait until the part is finished or regularly check on the part during the print to determine the part quality. Using data gathered from multiple sensors, a quality score can be used to …

Reclamation Of Fused Silica From Investment Shells Used For Casting Steel, Samuel L. Holt

College of Graduate Studies: Theses & Dissertations

Fused silica is widely used for investment casting shell molds. Fused silica shells are discarded after being used for casting one time. This is due to the transformation of fused silica to beta cristobalite above 1652℉ (900℃). To reduce cost and waste of investment casting foundries, this study is exploring a method to inhibit transformation of fused silica and reclaim it from high temperature investment casting shells. This research has employed firing to minimalize fused silica transformation to cristobalite. The phase transformation is minimalized due to sintering and coarsening of the particles during firing. Coarsening reduces surface area to volume …

Design And Development Of Soft Earthworm Robot Driven By Fibrous Artificial Muscles, Beau Ragland

College of Graduate Studies: Theses & Dissertations

Earthworm robots have proven their viability in the fields of medicine, reconnaissance, search and rescue, and infrastructure inspection. These robots are traditionally typically hard-shelled and must be tethered to whatever drives their locomotion. For this reason, truly autonomous capabilities are not yet feasible. The goal of this thesis is to introduce a robot that not only sets the groundwork for autonomous locomotion, but also is safe for human-robot interaction. This was done by ensuring that the actuation principle utilized by the robot is safe around humans and can work in an untethered design. Artificial muscle actuation allowed for these prerequisites …

A Numerical And Experimental Study On Effect Of Composition Of Ar-N2 Shielding Gas On The Weld Bead Profile And Its Prediction For Hot Wire Arc Additive Manufacturing, Niraj Pudasaini

College of Graduate Studies: Theses & Dissertations

Wire arc additive manufacturing is a process of making three-dimensional metal parts in a layer-by-layer approach using a feed wire and electric arc as a heat source. Wire arc additive manufacturing (WAAM) is becoming more popular due to its ability to create complex 3D parts, less build time, high deposition rate, and significant cost savings. Out of the many parameters used in WAAM, one of the important parameters is shielding gas which plays a significant role in material quality, properties, and defects. In this study, a controlled amount of Argon (Ar) and Nitrogen (N₂) shielding gases are used …

Hydrogen Fuel Cell Gasket Handling And Sorting With Machine Vision Integrated Dual Arm Robot, Devin C. Fowler

College of Graduate Studies: Theses & Dissertations

Recently demonstrated robotic assembling technologies for fuel cell stacks used fuel cell components manually pre-arranged in stacks (presenters), all oriented in the same position. Identifying the original orientation of fuel cell components and loading them in stacks for a subsequent automated assembly process is a difficult, repetitive work cycle which if done manually, deceives the advantages offered by automated fabrication technologies of fuel cell components and by robotic assembly processes. We present an innovative robotic technology which enables the integration of automated fabrication processes of fuel cell components with robotic assembly of fuel cell stacks into a fully automated fuel …

Enhancing Project Management With Lean World Class Manufacturing In Construction, Jacob Randles

College of Graduate Studies: Theses & Dissertations

In construction, the goal of commercial projects is to turn a profit. This is achieved by minimizing inputs and maximizing outputs while building a product that meets the customer’s perception of value. Value is determined through pre-negotiated specifications, plans, and material quality. Even in U.S. military construction, the unit executing the construction wants to complete the task on time and on budget, which can be difficult to do. Studies on project completion showcase a surprisingly high rate of failure in reaching the aforementioned “on time, on budget” goal. It is important to understand the nuances and details of U.S. Army …

Color Removal From Pulp Mill Effluent Using Coal Ash Produced From Georgia Power Coal Combustion Plants, Christopher B. Willett

College of Graduate Studies: Theses & Dissertations

Two environmental concerns currently face Georgia: coal fly ash (CFA) waste from coal power plants, and the effluent generated by pulp mills. Pulp mill effluent discolors surface waters into which it is discharged, and has been proven to negatively impact the dissolved oxygen and carbon necessary for aquatic life. The proposed solution is a cost-effective adsorption treatment using an inexpensive but abundantly available waste material: CFA. CFA possesses beneficial properties that allow it to effectively remove contaminants, and is available at significantly reduced cost. The primary research objective was to define treatment parameters that would result in the maximum removal …