Materials Science and Engineering Commons^™

Analysis Of Novel Corrosion Resistant Maraging Steels For Use In Additive Manufacturing, Bradley Michael Samuel, James Knowlton Smith

Materials Engineering

Stainless maraging steel has been proven to be an industry standard material for plastic injection molds. Its high hardness and corrosion resistance extend the lifetime of the tool. This alloy system is also well-suited to additive manufacturing, which can be utilized to form internal cooling channels, further increasing tool life. Using Rapid Alloy Development (RAD) Oerilkon METCO is developing a new composition of stainless maraging tool steel that has high hardness/strength, is corrosion resistant, and has additive-capable melting and solidification properties. This study tests the hardness and corrosion resistance of the new RAD alloys against the current market competitor Corrax …

Processing And Characterization Of Silicon Nitride For Rapid And Low-Level Detection Of Water Pathogens, Arielle H. Buchanan, Logan A. Chai

Materials Engineering

Water sanitation is a serious issue affecting the lives of many, and methods for assessing water cleanliness have been a major research interest for decades. Rapid and accurate water pathogen detection methods that can be performed in field applications have been a growing research focus, especially in low-income countries most affected by poor water quality. Silicon nitride was explored as a material for colorimetric water-pathogen sensing due to the large body of knowledge around its processing, and its isoelectric point. A bioassay of chlorophenol red-β-Dgalactopyranoside (CPRG) and β-galactosidase (β-gal) enzymes with Escherichia coli (E. coli) bacteria was used to examine …

In Situ Marine Biodegradation Of Poly(Lactic) Acid And Thermoplastic Starch Blends, Brittany Denicholas

Materials Engineering

Marine life has been suffering from macro- and microplastics since the inception of petroleum-based plastic. Bio-based biodegradable polymers such as PLA and TPS can help mitigate the damage done by petroleum plastics. Blending PLA and TPS can reduce the cost while preventing a significant effect on the material properties. PLA/TPS blend compositions such as 90/10, 80/20, 70/30 could be candidates for a solution. The PLA/TPS blends have been submerged in a marine environment at the Cal Poly Pier in Avila Beach for 8 weeks. Three sample sets containing three of each blend composition were collected every week and tested in …

Non-Destructive Material Analysis Of Metals And Composites Via Thermography, Jonathan R. Doubt, James L. Chapman

Materials Engineering

The Naval Surface Warfare Center, Port Hueneme Division, is interested in the development of non-destructive damage assessment of shipboard materials via drones at distance. Long Pulsed Thermography (LPT), a method of non-destructive evaluation, was investigated as a possible method for detecting damage in metals (5005h24 Al alloy and 1008 carbon steel) and composites (aramid fiber honeycomb sandwich structure) at distances from 0.5 m to 3.0 m. LPT was conducted using two 1000 W can lights to heat the samples, and a FLIR E8-XT thermal camera. The images were then analyzed using ImageJ software to determine if damage could be detected …

Citric Or Acetic Acid Effects On The Crosslinking Of Pvoh, Samuel Carr, Erika Szaldobagyi

Materials Engineering

Transportation and shipping processes are the most dangerous times for food due to harsh handling and frequent temperature changes. Plain corrugated boxes cannot withstand the damp environment caused by melting ice that is used to keep foods cold and fresh. To minimize damage, a protective polymer film coating can be applied. These coatings can be unsafe when used with food and will lead to excess waste by limiting the recyclability of the boxes. The purpose of this project was to produce nontoxic crosslinked PVOH films to determine suitability for a cost effective, biodegradable, and repulpable corrugated box coating. Polyvinyl alcohol …

Determining The Efficacy Of A Silica And Bacterial Cellulose Composite Model System, Hannah Martin, Daisy Kamp

Materials Engineering

Bacterial cellulose (BC) is a sustainable alternative to petroleum-based polymer films for synthetic leather applications. Synthesized by a symbiotic culture of bacteria and yeast, BC is a three-dimensional structure composed of cellulose microfibrils. However, pure BC lacks certain desirable properties such as high tensile strength. Previous studies have shown that loading BC with nanoparticles to form nanocomposites has improved BC’s mechanical properties. However, this was not studied as a function of particle size. This study focuses on using silica/BC nanocomposites to model the impact that particle size and silica soaking concentrations have on the uptake efficiency of these particles into …

Soil Degradation Of A Plastic Blend Of Opuntia Ficusindica Juice, Animal Protein And Beeswax, Isabel A. Gamez, Daniel R. Kava

Materials Engineering

Since the introduction of single use plastics in the early 1900s, their usage has increased exponentially. Unfortunately, due to this exponential increase there are negative environmental implications of their production, which requires further consideration. Currently, there are various waste disposal practices for SUPs, including landfilling, incineration, and recycling. Recent data revealed that only 14 % of plastic waste was recycled, with 40% of plastic waste being landfilled, while the rest of the plastic waste was incinerated or released to the environment at 14 % and 32 %, respectively. A potential solution to the plastic waste issue is developing a polymer …

Effect Of Oxygen Equivalence On The Strength And Toughness Of Ti-6al-4v Forgings, Kira Baylor, Clarissa Drouillard

Materials Engineering

Tensile testing and fracture toughness testing were conducted to establish a numerical relationship between interstitial content and performance in forged Ti-6Al-4V. The value of oxygen equivalence was used to represent the interstitial content by combining the weight percent of oxygen, carbon, and nitrogen. The correlation between oxygen equivalence and mechanical properties can be used to accurately predict the performance of forged parts. Samples of forged parts with varying levels of interstitial content were subjected to a recrystallization anneal at 75 F below the beta transus temperature to decrease microstructure variability across parts with a second anneal at 1300 F to …

Investigation Of The Effects Of Cladding Layers On Longitudinal And Transverse Mechanical Properties In Composite Laminates, Rachel Potratz, Tiffany Foo, Joseph Kamlet

Materials Engineering

The addition of cladding layers to composite laminates is used in industry to improve bond adhesion and the ease of manufacturing. However, there is no public data on the effects of cladding layers on the mechanical properties of composite components. To directly observe how cladding layers affect mechanical properties, four laminates with zero, one, two, and three cladding layers of twill fabric were added symmetrically to a biased core. The mechanical testing performed was tensile, short beam strength, and compression testing in the longitudinal and transverse directions. The measured strengths were related to the longitudinal properties of the core, and …

Model-Based Design Of An Optimal Lqg Regulator For A Piezoelectric Actuated Smart Structure Using A High-Precision Laser Interferometry Measurement System, Grant P. Gallagher

Master's Theses

Smart structure control systems commonly use piezoceramic sensors or accelerometers as vibration measurement devices. These measurement devices often produce noisy and/or low-precision signals, which makes it difficult to measure small-amplitude vibrations. Laser interferometry devices pose as an alternative high-precision position measurement method, capable of nanometer-scale resolution. The aim of this research is to utilize a model-based design approach to develop and implement a real-time Linear Quadratic Gaussian (LQG) regulator for a piezoelectric actuated smart structure using a high-precision laser interferometry measurement system to suppress the excitation of vibratory modes.

The analytical model of the smart structure is derived using the …

Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines, Kevin Gabriel Kuehn, Philip Randall Streeter

Materials Engineering

Polymer concrete is a composite material used to replace cast iron and steel in wafer grinding machines for vibration damping. During the grinding and lapping processes of manufacturing silicon wafers, excessive vibrations may cause subsurface damage which requires additional polishing and reduces yield. Nine compositions containing various levels of granulated rubber and glass fibers were manufactured. CRM WRF-10 granulated rubber was examined at 0%, 5%, and 10% and Corning Cem-Fil glass fibers were added at 0%, 0.5%, and 1% by weight. Smooth-On EpoxAcast 690 epoxy resin was held constant at 16% for each composition. Crushed granite aggregate from Martin Marietta, …

Optimization Of A Novel Nipam-Based Thermoresponsive Copolymer For Intramuscular Injection As A Myoblast Delivery Vehicle To Combat Peripheral Artery Occlusive Disease, Quentin R. Klueter

Master's Theses

There is a need for a minimally invasive delivery method to enable cell therapies to combat peripheral artery occlusive disease (PAOD) in end stage patients. Myoblasts show promise as a cell mediated therapy but warrant an improved delivery method to increase cell retention in the region of interest because of their adherent nature, relative to previously used BM-MNC’s that are non-adherent. Contemporary issues with achieving successful cell therapies of vasculature can be mainly characterized by the lack of clinical translation from promising animal studies and absence of cell delivery scaffolding. Naturally, polymers have been widely experimented with as grafts to …

Automated Mini-Tubular Ceramic Production, Hunter Brooks, Daniel Freeman, Leo Taranta-Slack

Mechanical Engineering

Researchers at Lawrence Livermore National Laboratory need a way to increase the rate of manufacturing of mini-tubular ceramics to be used in testing particulate air filters. This document outlines our process from researching and writing an initial scope of work all the way to fabricating and testing a final prototype. This journey takes us through the background research, ideation process and selection of a final design. We also detail the desired engineering specifications and our concept selection process. We dedicate a significant portion of this report to discussion of our final design. We delve into how it was manufactured as …

Minimizing Leakage In Thin Walled Structures Printed Through Selective Laser Melting, Andrew Spencer Yap

Master's Theses

In this project, the scan strategy of selective laser melting (SLM) for thin walled structures was investigated by changing laser parameters and tool path. Producing thin walled structures is difficult due to defects such as warpage and porosity. A layer on the SLM 125 consists of hatch volume, fill contours, and borders, however, for thin walls, hatch volume can become unavailable, resulting in a solely border/fill contour laser tool path.

Three central composite designs (CCD) were created to optimize the laser parameters of borders to minimize leakage rate and porosity. The two factors changed were border laser power and scanning …

Analysis Of The Use Of Waste Material In 3d Printing, Alexander Laurence

Materials Engineering

Globally, only 9% of plastic by mass is recycled. Allowing consumers to directly convert polyethylene terephthalate (PET) waste into 3D filament can increase the recycling rate by reducing contamination and costs from traditional large-scale recycling methods. This was tested by heating strips of PET to various temperatures within its glass transition region and pressing a roller with a 1.75 mm indentation against it to observe strip deformation. PET was also placed in a hemispherical well with a 1.75 mm diameter hole at the bottom and heated above its melting temperature to determine the mass of PET required to extrude 3D …

Effect Of Distal Core Flattening On 304 Stainless Steel Guide Wires, Khanh Phan

Materials Engineering

Abbott Vascular produces a variety of medical guide wires to accommodate a wide array of minimally invasive medical procedures. Certain types of these wires have the distal core flattened to improve specific properties such as flexibility and steerability. However, it is unknown how this affects the other mechanical properties of the wire. Abbott Vascular provided two types of wire to test the effects of distal core flattening on the mechanical performance of the wires. One group of wires was made from 304 single spring stainless steel with no flattening performed. The other group of wires was made from 304 triple …

Void And Density Analysis Of Cyanate Ester Composites, Cameron B. Atwood

Materials Engineering

In large scale composite manufacturing, voids and their frequency within prepreg materials play an important role in predicting the mechanical properties of a final composite laminate. The industry standard process for determining voids in composite materials is through resin digestion and resin ignition via ASTM D3171. One limitation to this standard is its ability to frequently produce negative void volume values in quality control testing, due to the calculation sensitivity of input resin and fiber densities. For this reason, Toray Advanced Composites wanted to investigate the process steps of ASTM D3171 to determine if discrepancies in resin density data may …

Newly Developed Antifouling Coating Alloys For Hydraulic Cylinder Applications, Christopher Liam Fahey, Robin Ashley Payne

Materials Engineering

In a marine environment solid surfaces are subject to corrosion and fouling, which is the buildup of unwanted material such as algae and barnacles, that can impede the functionality of components. The application that this project focuses on are hydraulic cylinders. Eight alloys, including three newly developed alloys, were tested for marine fouling performance. Three of the alloys were primarily NiCr, these included Inconel 625, Metco 1720, and P105-X3. Four alloys contained varying amounts of Cu, and these were Monel 400, CuproNickel, Monel 450, and P76-X24. Finally, one sample of a Co-based alloy was also tested, Ultimet. Of the samples …

Life Cycle Assessment Of An Ifixit Pro Tech Toolkit, Camden N. Webb, Dylan A. Ell

Materials Engineering

A life cycle assessment of an iFixit Pro Tech Toolkit was performed to determine the environmental impacts of iFixit’s best-selling toolkit. SimaPro software was used to measure three impact categories: energy usage, water consumption, and global warming potential. This project provides quantitative data on the resources required for repairing devices through use of the toolkit to ultimately reduce the global e-waste stream by re-using electronics. Using the cut-off method, global warming potential of the kit was 4.1 kg of CO₂ equivalents, water consumption was 1.5 m³, and energy usage was 73.9 MJ. Major contributors to these impact …

Dental Cement Thickening Agents For Mudslide Prevention, Kristina Emiliya Babayev, Emily Elizabeth Johnson, Diana Evet Reihaneh

Materials Engineering

The purpose of this project is to develop a non-toxic mud thickening agent for the application of decreasing mudslide intensity where performance is measured by flow rate, viscosity, and toxicity tests. We hypothesized that dental cements could be a potential candidate due to their adhesive, hydrophilic, and biocompatible properties. Zinc phosphate, glass ionomer, and polycarboxylate cement were among the dental cements tested. These tests were performed at low and high concentrations of 25 grams and 125 grams, respectively, mixed into soil to produce 3500 gram samples. The dental cements produced noticeable thickening effects in the mud, as the average viscosity …

Effect Of Dissolved Oxygen On Corrosion Of Carbon And 13cr Steel In A Brine Environment, Kevin Peter Iu, Andy Zhou

Materials Engineering

Oxygen corrosion is a major threat to seawater injection systems that are part of offshore drilling operations. Seawater is typically deoxygenated to an industry standard of(DO) by injection through a deaeration column followed by treatment with oxygen scavenging chemicals. Commercial simulation software like OLI Studio: Corrosion Analyzer predicts high corrosion rates when injection seawater contains high DO levels, justifying deoxygenation. However, a notable lack of experimental data exists concerning the effect of varying levels of dissolved oxygen on corrosion rate. The goal of this project is to measure the effect of three dissolved oxygen levels (0, 62, and 620 ppb) …

Uv Polymerization Of A Zwitterionic Antifouling Membrane Coating, Amanda Jia-Hwa Tsai, Vincent Matthew Guarino

Materials Engineering

Membrane filtration is used in a wide array of industries to separate components in a mixture. Filtration membranes suffer from the external deposition of pollutants and microorganisms, a phenomenon known as fouling. Fouling reduces the lifetime of a membrane and therefore increases production costs. The goal of this project was to modify the surface of a hydrophobic commercial membrane with a charged coating to induce antifouling properties. A zwitterionic monomer, sulfobetaine methacrylate (SBMA), was used for its steric hindrance and hydration shell formation mechanisms, which result in superior non-specific antifouling performance. When polymerizing the coating onto the surface of the …

Effects Of Uv Exposure On The Thermo-Mechanical Properties Of Cactus Based Biopolymers, Madison Glozer, Megan Bolling, Addison Wolfson

Materials Engineering

The viability of renewable biopolymers as sustainable alternatives to synthetic plastics is promising, however ultra-violet (UV) radiation can lead to premature degradation and reduction in the material’s performance. Biopolymers comprised of nopal cactus juice, animal protein, natural wax, and glycerin in differing percentages were studied to obtain thermo-mechanical data in relation to UV exposure. To quantify degradation, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, goniometry and gravimetric measurements were performed. Each formulation experienced mass loss as a result of UV exposure, which could be attributed to water evaporation. The thermogravimetric analysis indicated a reduction in the second …

The Effects Of Glass Fiber Fillers On Epoxy Resin Performance, Ashton Robert Reinhold, Manuel Jose Aguirre Ii

Materials Engineering

Premature failure of filtration members in biochemical processing is a costly issue for manufacturers. This research aims to determine whether or not the premature failure due to thermal fatigue in medical filtration devices can be mitigated by glass fiber addition. The study was conducted to identify the effects of e-glass fiber filler content in an epoxy matrix on the mechanical and thermal properties of the epoxy system. The epoxy was evaluated over a filler content of 0-50wt% in level increments of 12.5wt% and temperatures ranging from ambient to 160°C in increments of 15°C. Cylindrical and tensile bar specimens were prepared …

Solvent Analysis Of Phenolic Resin Glass Fiber Reinforced Prepreg During Out-Time, Sixin Zhai, Crystal Ipong

Materials Engineering

Phenolic resin glass fiber reinforced prepregs are highly suitable for airplane interior components due to their high fire resistance, high temperature performance, and low-density characteristics. Safran Cabin seeks to improve their storage of the phenolic resin prepreg during their manufacturing process. The issues the company faces are the occasional delamination of prepreg laminas or the loss of tackiness rendering the lamina unfit for use. The area of investigation was determining the weight loss of volatiles during out-time. The term “out-time” consists of the time the prepreg experiences in transit, on the shop floor, and in short-term temperature-controlled storage. Simulated storage …

Reducing The Fouling Of Microfiltration Membranes Through Uv-Initiated Surface Modifications Using Poly (Ethylene Glycol) Based Monomers, Christopher Lo, Matthew Truong

Materials Engineering

Meissner Filtration Product Inc. designs and manufactures membranes for food and beverage, microelectronics, ultrapure chemicals, and pharmaceutical industries. Membrane filters utilized in these industries have lifetimes greatly limited due to membrane fouling. Increasing membrane lifetime will reduce downtime, waste, and cost of operation. The proposed project is aimed to develop a methodology for synthesizing a fouling-resistant polymer coating layer on hydrophobic membrane surfaces for reducing membrane fouling and increasing membrane filterability (membrane lifetime) that are critical for effective membrane operations in the pharmaceutical industry. In this study, commercial membranes were coated with a solution containing a monomer, crosslinker, and photoinitiator …

Development Of A Marine Biodegradable Target Balloon, Blake Samuel Robinson, Arash Sam Akhavi, David Leonardo Albarran-Martinez

Materials Engineering

The US Navy utilizes PVC target balloons, known as Killer Tomatoes, that are inflated onboard a naval vessel then deployed into the ocean to calibrate a variety of weaponry. The Navy has requested the investigation of biodegradable polymers to replace the PVC in attempts to reduce ocean waste that is generated from the leftover PVC material. After communicating with American Pacific Plastic Fabricators (APPF), the current manufacturer of the Killer Tomatoes, we gained an understanding of the manufacturing process and the material requirements that would allow a new material to be integrated into their current process. Two proprietary, trial polymers …

Strengthening Of 7175 Aluminum Alloy Through Multi-Step Aging Process, Colin E. Masterson, Ryland W. Jolliffe

Materials Engineering

7175 is a heat-treatable aluminum alloy commonly used in aerospace forgings. This alloy is aged with a multi-step heat treatment. This treatment must balance strength with stress corrosion cracking resistance through a degree of overaging. The team was tasked by Weber Metals to increase the strength of this treatment without sacrificing stress corrosion cracking resistance. Both two-step and retrogression and reaging treatments were tested in experiments to find a heat treatment that could increase the yield and tensile strength by 1-2 ksi while maintaining a minimum electrochemical conductivity equivalence of 38% relative to copper. Two-step aging is the more conventional …

Pressure Driven Desalination Membranes: Lyotropic Liquid Crystals Containing Single Walled Carbon, Matteo A. Del Giudice, Samantha Castillo Merigold

Materials Engineering

This project presents a potential alternative desalination technique that utilizes the ion rejection properties of single walled carbon nanotubes dispersed in a lyotropic liquid crystal (LLC) matrix. Previous research has pointed to the polymerizable surfactant methacryloxy ethyl hexadecyl dimethyl ammonium bromide (C16MA) having capabilities of filtering molecular components smaller than a nanometer, when oriented in cylindrical micelles. SWCNTs were dispersed in deionized water by probe sonication and addition of surfactant cetyltrimethylammonium bromide (CTAB) due to SWCNTs’ hydrophobic properties. Membranes were produced containing 55wt% C16MA, 37wt% DI water, 0.1wt% with respect to the monomer (WRM) SWCNTs, 1.9 wt% WRM 2,2-dimethoxy-2-phenylacetophenone (photointiator), …

Metallurgical And Thermal Processing Investigation Of Additively Manufactured Superalloys Jbk-75 And Nasa-Hr-1, Allyse Birken, Derek Noel

Materials Engineering

Aerojet Rocketdyne is investigating the use of directed energy deposition (DED), an additive manufacturing process, to reduce cost and lead time for manufacturing complex rocket engine components for their RS-25 engines. JBK-75 and NASA-HR-1, two Fe-Ni-base, age-hardenable (γ′) superalloys, are used for nozzle structural jackets and hot gas manifolds. Currently, these parts are produced using traditional forging or casting methods followed by intensive machining operations. Additionally, these alloys were designed for use in the wrought condition and require a different set of post-processing heat treatments when produced using DED due to their dendritic, segregated microstructure in the as-built condition. Homogenization …