Engineering Commons^™

The Effect Of Compaction Temperature And Pressure On Mechanical Properties Of 3d Printed Short Glass Fiber Composites, Pushpashree Jain Ajith Kumar Jain

Mechanical & Aerospace Engineering Theses & Dissertations

Among many thermoplastics that are used in engineering, polyamide 6 (nylon 6) is an extremely versatile engineering thermoplastic. Nylon filled with glass fibers has higher mechanical strength and high wear resistance than general purpose nylon. 3D printed composites, based on fused filament modeling, typically suffer from poor bead-to-bead bonding and relatively high void content, limiting their mechanical properties

This thesis explores the effect of compaction pressure and temperature on improving the mechanical properties of 3D printed composites. Engineering moduli in the printing and transverse to printing direction, as well as ultimate strength were measured using the tensile testing with Digital …

Characterization Of Simulated Low Earth Orbit Space Environment Effects On Acid-Spun Carbon Nanotube Yarns, Ryan A. Kemnitz, Gregory R. Cobb, Abhendra K. Singh, Carl R. Hartsfield

Faculty Publications

The purpose of this study is to quantify the detrimental effects of atomic oxygen and ultraviolet (UV) C radiation on the mechanical properties, electrical conductivity, and piezoresistive effect of acid-spun carbon nanotube (CNT) yarns. Monotonic tensile tests with in-situ electrical resistance measurements were performed on pristine and exposed yarns to determine the effects of the atomic oxygen and UVC exposures on the yarn’s material properties. Both type of exposures were performed under vacuum to simulate space environment conditions. The CNT yarns’ mechanical properties did not change significantly after being exposed to UV radiation, but were significantly degraded by the atomic …

Sintering Behavior, Structural, And Catalytic Properties Of Ytterbium Oxide (Yb2o3), Alina Aftab

Honors Undergraduate Theses

Ytterbia (Yb₂O₃) is an oxide ceramic, whose magnetic properties and crystal structure were studied to some extent in the past. However, the information on Yb₂O₃'s catalytic properties is lacking. Therefore, in this work, the sintering behavior and catalytic properties of Yb₂O₃ were examined. Yb₂O₃ ceramic samples were made using pressureless sintering of the commercially available Yb₂O₃ with 99.99% purity powder. The powder was first uniaxially pressed at 20 MPa in a steel die followed by pressureless sintering at different temperatures of 900 ⁰C …

Influence Of Grain Size And Widmanstätten Colonies On Variability Of Tensile Properties Of Forged Ti-6al-4v, Blake T. Gaspar

Master's Theses

When testing forgings for specifications, it was found that some parts did not meet the requirements for mechanical properties. This triggered an investigation into two of the parts from the lot that did not meet specification. The ultimate reason for failure was due to lower than necessary yield strength and ultimate tensile strength values, as well as unwanted variability between regions of the part. Therefore, samples of the regions were tensile tested to determine the differences that existed in yield strength, ultimate tensile strength, and elongation. After tensile testing, quantitative metallography and fractography were conducted to identify aspects of the …