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Full-Text Articles in Engineering
Corrosion Of Stainless Steel 316l And Astm F75 Cobalt Chromium Alloy During Immersion Testing In Silver Salt Solutions, Meagan Higgins
Corrosion Of Stainless Steel 316l And Astm F75 Cobalt Chromium Alloy During Immersion Testing In Silver Salt Solutions, Meagan Higgins
Materials Engineering
This study evaluates the potential effects of silver salts on biocompatible metals used for prostheses during the chemical reduction process to produce a silver antimicrobial layer on the metal’s surface. Samples of two biocompatible metals were obtained: Stainless Steel 316L and ASTM F75 Cobalt Chromium Alloy. Three different silver salts were also acquired: silver nitrate, silver sulfadiazine, and silver chloride. Specimens of each metal were cut to size using a 4-1/2 inch aluminum oxide, 40 grit, cut off wheel for metal, attached to a Dewalt Angle Grinder. The biocompatible metal samples were then subject to either Solution 1, water with …
Analysis Of Failed Forging Saddling Mandrels And Process Improvements For Increased Mandrel Lifespan, Brock Costalupes
Analysis Of Failed Forging Saddling Mandrels And Process Improvements For Increased Mandrel Lifespan, Brock Costalupes
Materials Engineering
This project seeks to increase the lifespan of steel mandrels used by Schlosser Forge in the saddling process, which is part of the production of forged rings for the aerospace and power generation industries. All saddle mandrel samples were taken from used 4340 steel mandrels. Hardness profiles were measured across rectangular bars cut from the transverse direction of a completely fractured piece of a 7″ diameter mandrel. The hardness near one outer surface of the tested bar was 36 HRC and gradually decreased to 30.5 HRC at the opposite surface. Macroscopic examination of the primary fracture surface along with light …
An Exploratory Investigation Into How Cold Working Can Affect The Acoustic Performance Of Thin Aluminum Foil In A Ribbon Microphone, Alexander (Alex) Stanley
An Exploratory Investigation Into How Cold Working Can Affect The Acoustic Performance Of Thin Aluminum Foil In A Ribbon Microphone, Alexander (Alex) Stanley
Materials Engineering
Ribbons of 4 μm thin 99.1% pure aluminum foil were cut and corrugated to replace the stock ribbon in an Apex 205 ribbon microphone. Prior to corrugation, half of the ribbons were sandwiched between two KimWipes and two pieces of cardstock then hammered to impart strain hardening. Each ribbon was placed into the microphone capsule and the frequency response of each ribbon was measured. A 10 second sine sweep from 20-20,000 Hz was played through a KRK Rokit 5 speaker and recorded through a ribbon microphone placed 6 inches away from the speaker cone. The signal generated by the ribbon …
The Synthesis And Characterization Of Gold And Silver Nanoparticles In Formal And Informal Settings, Mathew Wynn
The Synthesis And Characterization Of Gold And Silver Nanoparticles In Formal And Informal Settings, Mathew Wynn
Materials Engineering
Silver nanoparticles were synthesized through the reduction of AgNO3 using NaBH4. The borohydride anions were adsorbed onto silver nanoparticles. The repelling forces of the borohydride anions prevented the aggregation of particles, but the addition of an electrolyte or agitation induced aggregation. A yellow hue was given off by the silver nanoparticle sol that, using a spectrophotometer, had plasmon resonance at 386 nm. The silver nanoparticles were estimated to be 10 to 20 nm in diameter. Gold nanoparticles were synthesized through the reduction of HAuCl4 using Na3C6H5O7. The gold nanoparticle sol gave off a red hue that had plasmon resonance at …
Design And Development Of An Interactive Materials-Based Learning Kit For K-4 Grade Levels, Thomas Agasid, Santiago Caceres, James Woodhead
Design And Development Of An Interactive Materials-Based Learning Kit For K-4 Grade Levels, Thomas Agasid, Santiago Caceres, James Woodhead
Materials Engineering
The Materials Safari Adventure kit was designed to help introduce basic materials concepts to young audiences in kindergarten through fourth grade levels. The primary goal of this project was to design a tool to spark an interest in materials science for young children, while revealing the field of materials science to parents and educators. The final kit design incorporates a safari theme to encourage imagination and promote self-directed learning through the interaction with materials. Materials were selected to showcase a range of properties within three materials classes: metals, polymers, and natural woods. A total of 9 materials were chosen for …
The Effects Of Concentration, Stir Rate, And Processing Temperature On The Iridescence Of Polymethyl Methacrylate Nanoparticles, David Baruela
The Effects Of Concentration, Stir Rate, And Processing Temperature On The Iridescence Of Polymethyl Methacrylate Nanoparticles, David Baruela
Materials Engineering
Synthetic opals were synthesized by creating polymethyl methacrylate (PMMA) nanospheres in order to determine which conditions would create the best iridescent samples. The factors affecting the iridescence were nanosphere concentration, stir rate, and processing temperature. PMMA solutions were made by adding 17 mg of granular azobis to a solution of 16 mL of distilled water with 3 mL of methyl methacrylate (MMA). The solution was stirred at different rates, slow and fast, and different temperatures, 70 °C and 90 °C, under a constant flow of nitrogen gas for 40 minutes until the polymerization reaction was complete. Glass substrates were prepared …
Al2O3 Oxide Morphology For Two Fe-Cr-Al Stainless Steel Foils Used In Gasoline Engine Catalytic Converters, Jennifer Suiter
Al2O3 Oxide Morphology For Two Fe-Cr-Al Stainless Steel Foils Used In Gasoline Engine Catalytic Converters, Jennifer Suiter
Materials Engineering
Corrugated 0.05 in thick strips of Fe-Cr-Al ferritic stainless steel samples with 4% and 6% aluminum were heat treated, and the resulting Al2O3 oxide was analyzed using SEM imaging. Three heat treatment cycles were carried out for each sample. The heat treatments were based on future metal-substrate catalytic converter processing prior to applying the washcoat Each heat treatment started with a 90 minute ramp from room temperature to 538°C and a 32.5 minute ramp from 538°C to 899°C. The three different dwell periods at 899°C were 4 hours, 6 hours, and taking a sample out every hour …
The Design And Fabrication Of A Silicon Membrane For Electrostatic Actuation, Elizabeth L. Brooks
The Design And Fabrication Of A Silicon Membrane For Electrostatic Actuation, Elizabeth L. Brooks
Materials Engineering
An electrostatically actuated silicon membrane was designed and fabricated utilizing a siliconon- insulator wafer. The SOI wafer contains three layers- a 400μm thick “handle” layer of silicon followed by a 2μm thick oxide layer topped with a 20μm thick “device” layer of silicon. The embedded oxide layer acts as an etch-stop during silicon etching, leaving a thin membrane of consistent thickness on the device side. The device dimensions were chosen to provide acceptable membrane deflection predicted by calculations and Finite Element Analysis. A microfabrication process plan was designed to produce thin membranes appropriate for electrostatic actuation. A 700nm layer of …
Correlation Between 90o Tensile And 90o Flexural Properties For Thermoplastic Based Carbon-Fiber Composites, Amy Lautenbach
Correlation Between 90o Tensile And 90o Flexural Properties For Thermoplastic Based Carbon-Fiber Composites, Amy Lautenbach
Materials Engineering
Thermoplastic matrix composites containing carbon fibers and 4 different resins (TP 1-TP 4) were tested in tension with the fibers at 90 degree to the longitudinal axis following ASTM D 3039-00. The tensile strengths varied from 5.07-13.87 ksi with TP 1 as the strongest, and TP 4 as the weakest. SEM images were taken of the fracture surface of the samples to explore the fiber-matrix interaction. The SEM images showed significantly more wetting of the fibers in the higher strength materials. The SEM images of the two stronger materials showed resin coating the fibers even after fracture while the two …