Materials Science and Engineering Commons^™

Mechanical Properties Of Solid-State Resistance Welded Nitinol - 304 Stainless Steel Joints In Peripheral Guide Wires, Jennifer Rowe

Materials Engineering

Abbott Vascular manufactures medical guide wires that consist of 304 stainless steel wire joined to superelastic nickel titanium (Nitinol) wire by a solid-state resistance butt welding process. The objective of this project was to develop a deeper understanding of the mechanical properties of the welds in the guide wires. The wires tested were manufactured using two different processes and then ground to various diameters in the weld region. Vickers microhardness measurements were collected in the longitudinal direction across the heat-affected zones of the welds, as well as the transverse direction across the diameters of the welds. Micrographs of the welds …

Buckling Strength In Carbon Fiber Polymer Matrix Composites Produced By Filament Winding For Structural Use In Rockets, Kyle Rosenow

Materials Engineering

High-powered rockets use thin walled carbon-fiber reinforced polymer (CFRP) tubes as the primary structure and the tubes experience compressive stress during flight, which is estimated at 18MPa. Cal Poly Space Systems (CPSS) recently acquired the capability to use filament winding for manufacturing CFRP structures. Filament winding wraps carbon-fiber tow coated in epoxy around an axisymmetric object, and in this case, an aluminum cylinder. The tube laminate is an angle-ply orientation testing the winding angles 35°, 50°, 65°, and 80° and winding patterns 1/1 and 8/1 in combination using an unsupported parallel compression test. Coupons are one-inch in height, 2.5 inches …

Effect Of Metal Organic Framework Concentration On The Crystallization Of Pla-Al-Mof Composites, Eric Futak, Jeffrey Norton, Jessie O'Connell, Nestor Vazquez

Materials Engineering

Poly(lactic acid) (PLA), a well-known biopolymer, is lacking in barrier properties and toughness. The research goal of this project is to look at the crystallinity of PLA when combined with metal organic framework (MOF). It is speculated that MOF has an effect on PLA chain mobility, and therefore crystallinity. In this study, aluminum MOF was added to PLA in varying concentrations (0, 0.5, 1, 2, 5, 10, and 20 wt%) to observe the crystallinity of the composite. The resulting PLA-Al-MOF composite films were characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron …

Reducing Food And Packaging Waste Through Developing Edible Fruit Based Packaging Prototypes, Melanie Thatcher

Materials Engineering

Packaging is used to contain, preserve, protect, and advertise both manufactured and natural products. In 2013 it was reported that over thirty percent of solid waste in the United States was from packaging. One way to reduce the impact of packaging on the environment is to create a solution that is edible and sourced from a waste or secondary food product that is not currently being utilized. Food-contact packaging made from recycled materials must meet strict U.S. Food and Drug Administration (FDA) regulations to be utilized as raw material for packaging. Fruit pomace is a candidate material since it may …

Investigation Of Outlife Time On The Environmental Durability Of P2-Etched, Adhesively-Bonded Aluminum Alloys Using The Astm Wedge Test, Daniel Gross, Corey Sutton

Materials Engineering

P2 etchant is an environmentally-friendly aluminum etchant which has the potential to replace the Forest Products Laboratory (FPL) etchant as the industry standard. Environmental durability of adhesively-bonded aluminum surfaces etched using a paste version of the P2 etchant were tested using the Boeing-developed wedge test (ASTM D3762 - 03(2010)). This project specifically aimed to examine the relationship between outlife time (the time between etching and adhering) and the ability of bonded aluminum samples to pass the wedge test. Two aluminum alloys, 2024-T3 and 7075-T6, were wedge tested and the etched surfaces examined with an atomic force microscope (AFM) and a …

Improving Surface Roughness Of Optically Telegraphed Composite Laminations, Michael Smith

Materials Engineering

In collaboration with Watson Furniture, this project seeks to identify the cause of surface roughness on composite panels processed into commercial furnishings. The surface roughness was examined and measured using an optical microscope, a scanning electron microscope (SEM), and a profilometer. The SEM and optical microscope provided qualitative data on the surface roughness as well as the film build of each layer. After an initial characterization of the manufactured samples provided by Watson Furniture, additional samples were fabricated for testing using different manufacturing processes than those used by Watson Furniture. These samples were constructed in-house using raw materials provided by …

Effect Of Hydrogen Pick-Up And Release Behavior On The Tensile Properties Of Electroplated 4340m High-Strength Steel, Blake Daylor, Joshua Fisher, Alan Michelen Ruiz

Materials Engineering

Hydrogen embrittlement of high-strength steel (4340M) was quantified through tensile testing and fractography (SEM). Three types of samples were obtained: rotating beam fatigue specimens, round (notched) tensile specimens, and flat panel specimens. In addition, three different plating types were analyzed (Ni, Cr, Cd-Ti) with a set of samples that was shot peened and a set that was not. Since some of the samples went through a hydrogen relief bake, another factor in our experiment was the amount of time it took for the samples to reach the baking process after they were electroplated (bake delay). There were three levels of …

Controlling Grain Size In Cold Worked And Annealed 1100 Aluminum To Optimize Ductility In Rocket Diaphragm Systems, Ryan Lewis, Bryce Simmons, Jessica Williams

Materials Engineering

Liquid propellant rocket diaphragms require extreme ductility. 1100 Aluminum is used for its high ductility, but the post-processing cold work and subsequent anneal result in excessively large grains. The effect of heat treatment and cold work on grain size in 1100 aluminum was explored. The samples were cold worked to 0, 5, 10, 15 and 30% using tensile elongation. The samples were then heat treated per AMS 2770 with either a "Steel Conduction" (1000 – 1150°F/min) or a "Production" (16 – 18°F/min) heating rate. The grain size of the samples were measured using the mean lineal intercept method. The grain …

Biomimetic Seal Flipper Test Rig, Gordon D. Belyea, Laura Kawashiri, Dylan Rinker, Kurt Beske

Mechanical Engineering

No abstract provided.

The Design And Construction Of A Rear Bumper With Incorporated Spare Tire Rack, Alan C. Isaacson

BioResource and Agricultural Engineering

This senior project outlines the design and construction of a rear bumper with incorporated spare tire and equipment rack for a 1946 Willys CJ2A Jeep. The spare tire rack is capable of swinging out away from the vehicle to allow for the use of the vehicle’s tailgate. The bumper was designed for strength, functionality and aesthetic qualities alike. Additionally, the bumper design considered all vehicle codes and regulations.

Life Cycle Assessment Of Paper Versus Electronic Assignment Submission In Cal Poly's Materials Engineering, Patrick Mcdonnal

Materials Engineering

Both hard and soft copy submission of assignments make an impact on the environment to produce the final product in terms of energy consumption and carbon emissions; an investigation was conducted as to which method is less environmentally impactful. Student disposition towards each assignment submission method was also investigated because it is associated with learning efficacy. A survey was conducted in Cal Poly’s Materials Engineering Department to determine the contributing components to the environmental impact of paper and electronic assignments, as well as the students’ disposition towards each of them. Contributing components are man-made products used by a student to …

Life Cycle Assessment And Comparison Of Magnesium Oxide Nanoparticles Prepared By Aqueous And Microwave Synthesis Methods, Jesse Cartland

Materials Engineering

Abstract: Magnesium oxide nanoparticles are being used increasingly as catalysts for organic synthesis, fuel oil additives, and CO₂ adsorbents. There are many ways to produce magnesium oxide nanoparticles, but there is little information available regarding the environmental costs of production. As demand for environmentally friendly materials increases, it is important to understand environmental impact differences between various production methods. This study will compare the differences in embodied energy and global warming potential (GWP) between two synthesis methods: microwave combustion synthesis (microwave synthesis) and oxidation of magnesium hydroxide (aqueous synthesis). The resulting nanoparticles were characterized using scanning electron microscopy (SEM), …

Metals Additive Manufacturing Powder Aging Characterization, Thomas Russell Lovejoy, Nicholas Karl Muetterties, David Takeo Otsu

Mechanical Engineering

The metallic additive manufacturing process known as selective laser melting requires highly spherical, normally distributed powder with diameters in the range of 10 to 50 microns. Previous observations have shown a degradation in powder quality over time, resulting in unwanted characteristics in the final printed parts. 21-6-9 stainless steel powder was used to fabricate test parts, with leftover powder recycled back into the machine. Powder samples and test specimens were characterized to observe changes across build cycles. Few changes were observed in the physical and mechanical properties of the specimens, however, there were indications of chemical changes across cycles. Potential …

Minimization Of Metamerism In Wood Grain Printing Using Different Gcr Settings, Vinay Anil Turke

Masters Theses

In printing industry, prototyping is necessary to ensure quality reproduction of jobs. Conventional printing processes like gravure cannot be used for prototyping because of high manufacturing cost of gravure cylinders. Such challenges can be successfully tackled by use of relatively cheap and flexible printing processes, such as inkjet. Even though inkjet printing is a cost effective way for prototyping, it has its own limitations, especially in the case of woodgrain printing. Wood-grain patterns need to be printed with a release coating and adhesive. Inkjet printers are incapable of printing release coating and adhesive because release coat and adhesive require certain …

Microstructural Properties And Four-Point Bend Fatigue Behavior Of Ti-6.5al-2zr-1mo-1v Welded Joints By Electron Beam Welding, Peng Liu, Tongguang Zhai, Yuanbin Zhang

Chemical and Materials Engineering Faculty Publications

With the help of a four-point-bend of fatigue rig, high-cycle fatigue tests were carried out on an Ti–6.5Al–2Zr-1Mo-1V titanium alloy at room temperature, 20 Hz and R = 0.1 in ambient air. The test results indicated that the fatigue strength of base metal, 888 MPa, is about 120% of yield strength. The fatigue strength of joints is 814 MPa. It is about 110% of yield strength of base metal. When the loading stress is higher, the fatigue failure region is located in middle weld zone of weld face, which the cracks are propagated along coarse β phase’s grain boundary. When …

Low-Cost Prosthetic Transfemoral Socket, Emelie Deans, Joshua Ledgerwood, Leah Moore, Shaina Jung, Kristen Temnyk

Mechanical Engineering

The goal of this senior project was to design and fabricate a low-cost adjustable prosthetic socket for above the knee amputees. This low-cost consideration was incorporated with the original intent to be used in Fiji, however, this changed to the Dominican Republic. It became clear that the need for an adjustable socket was more as a transitional socket. This transitional socket would be used for the first 6 -12 months upon amputation because this when the most amount of volume fluctuation occurs. The project sponsor, LIM Innovations, has already designed the Infinite Socket which contains four main functioning parts: baseplate, …

The Recent Development Of New Pigment Binders, Jae Young Shin

Dissertations

Pigment coatings are applied onto paper and paperboard to improve their appearance and printability. For pigmented coatings, pigments and binders are the most important ingredients so their selections are critical.

Pigment binders not only perform the basic required role of binding pigment particles to each other and bonding the base sheet, but also significantly influence the rheology, coater runnability, and drying behaviors of the coating formulation and the optical, viscoelastic, and printing properties of coated paper and paperboard products.

When considering the relative amount of binders to use in a coating, one may speak about main binder, co-binder and sole-binder. …

Flexographic Printing Of Conductive Silver Inks Onto Pdms: Surface Treatment And Novel Processes For Creating Printed Electronic Devices, Michael James Joyce

Dissertations

For the continued advancement of the field of printed electronic (PE), there is a need for a better understanding of the interactions between functional inks and substrates, which is required to optimize printability, mechanical, and functional properties for the creation of more robust and efficient printed devices. This body of work aims to advance the knowledge of the material properties of poly-di-methyl-siloxane, PDMS, films, their interactions with flexo inks, and their flexographic printability. As the printing of metals (i.e., Ag & Au) is a known area of interest pertaining to PE, this work focused on the characterization and optimization of …

Coupling Between Magnetic Exchange And Charge Activation In Cu-Doped Lafeo3, Emir Dogdibegovic, Qingsheng Cai, William Joseph James, William B. Yelon, Harlan U. Anderson, Jin Bo Yang, Xiao Dong Zhou

Chemistry Faculty Research & Creative Works

Material research on perovskite-type oxides (ABO₃) has been driven by the recognition of their unique properties primarily attributed to the presence of oxygen octahedron (BO₆). Since 2003, the discovery of strong coupling in TbMnO₃ and BiFeO₃ has stimulated new interests in understanding the relationship between magnetic and electric properties in perovskites. In this article, we report our recent work on the magnetic superexchange interaction and charge formation in copper-doped LaFeO₃ using high-temperature neutron diffraction and thermoelectric measurements. In situ neutron diffraction measurements show a loss of antiferromagnetic ordering above 450°C. With an increase …

Finite Element Modeling Of Delamination Damage In Carbon Fiber Laminates Subject To Low-Velocity Impact And Comparison With Experimental Impact Tests Using Nondestructive Vibrothermography Evaluation, George Rodriguez Iv

Master's Theses

Carbon fiber reinforced composites are utilized in many design applications where high strength, low weight, and/or high stiffness are required. While composite materials can provide high strength and stiffness-to-weight ratios, they are also more complicated to analyze due to their inhomogeneous nature. One important failure mode of composite structures is delamination. This failure mode is common when composite laminates are subject to impact loading.

Various finite element methods for analyzing delamination exist. In this research, a modeling strategy based on contact tiebreak definitions in LS-DYNA^®was used. A finite element model of a low-velocity impact event was created to …