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Mechanical Properties And Tension-Tension Fatigue Behavior Of A Novel Additively Manufactured Polymer Matrix Composite At Room And Elevated Temperature, Grayson M. Harber
Mechanical Properties And Tension-Tension Fatigue Behavior Of A Novel Additively Manufactured Polymer Matrix Composite At Room And Elevated Temperature, Grayson M. Harber
Theses and Dissertations
The tension-tension fatigue behavior of a novel additively manufactured AM carbon fiber reinforced polymer matrix composite was studied. This novel material system consists of T1100 carbon fibers, and a UV photocured resin developed by Continuous Composites and Sartomer. Tensile properties and tension-tension fatigue were investigated for the 090 fiber orientation as well as for the ±45 fiber orientation. Specimens with 0/90 fiber orientation were tested at ambient laboratory temperature 23 °C and at elevated temperature 150 °C, while the specimens with the ±45 fiber orientation were tested only at ambient laboratory temperature. Tension-tension fatigue testing was carried out with a …
Finite Fatigue Life Prediction Of Additively Manufactured Aircraft Engine Turbine Blade With Respect To Internal Defect Size And Location, Daniel G. Miller
Finite Fatigue Life Prediction Of Additively Manufactured Aircraft Engine Turbine Blade With Respect To Internal Defect Size And Location, Daniel G. Miller
Theses and Dissertations
Current fatigue life modeling techniques with respect to defects emphasize the dependence on the defect size with respect to fatigue life, but does not account for the effects of where a defect might be located. This research outlines a process to include defect location into the model analysis for a more precise prediction of the number of cycles to failure and where the finial failure could occur within a component. The focus is on a turbine blade structure using IN718 subjected to a pure vibratory load. The basic model predicts component life using a stress map from the frequency analysis …
Additive Manufacturing Of Molybdenum For High Temperature Structural Applications, Megan L. Bustin
Additive Manufacturing Of Molybdenum For High Temperature Structural Applications, Megan L. Bustin
Theses and Dissertations
This research considered additive manufactured (AM) molybdenum (Mo) and the effect of three variables on microstructure, mechanical properties, and the relationship between the two. Test temperature, laser speed, and shield gas or build atmosphere were varied, and samples tested and analyzed using a three-point bending test, chemical composition, and optical and scanning electron microscopy. The relationship among variables and results using a Design of Experiments was limited compared to the inclusion of every tested sample. Most effects were expected: samples tested at room temperature were brittle without statistical significance; increasing laser speed resulted in decreased ductility and strain, smaller grain …
Performance Study Of Post-Processed Additively Manufactured Low Thrust Nozzles, Tyler W. Gerhold
Performance Study Of Post-Processed Additively Manufactured Low Thrust Nozzles, Tyler W. Gerhold
Theses and Dissertations
This research explores metal post-processing techniques to effectively reduce the large anomalous protrusions found in small additively manufactured low thrust rocket nozzles. Research has found that nozzles of this kind can experience losses in thrust of over 40%. Analytic theory of adiabatic nozzle flow with viscous losses for additively manufactured nozzles does not align with what has been found when tested experimentally. Compressible flow losses, such as shock wave formation inside the nozzle diverging cone, are likely the leading causes of such loss. Reduction in nozzle irregularities can likely yield results seen in analytic theory with similar performance to traditional …
Potential Solution To Meet Growing Demands Of Refractory Metal: Selective Laser Melting Of Molybdenum-Tungsten Alloy, Jae Yu
Theses and Dissertations
Selective laser melting (SLM) of refractory metals has been of high interest in research due to the metals’ potential desirable characteristics in aeronautical and space applications. In particular, molybdenum and tungsten have been the focus of several studies in the search for high temperature and high strength purposes in applications like supersonic aircraft, re-entry vehicles, nuclear fission, power generation, and other space systems. However, there is still a significant knowledge gap to process defect-free alloys and making use of them in practical engineering functions. The aim of this study is to characterize the relationship between the microstructure and mechanical properties …
Investigation Of Additively Manufactured Molybdenum-Tungsten-Rhenium Alloys, Randolph T. Abaya
Investigation Of Additively Manufactured Molybdenum-Tungsten-Rhenium Alloys, Randolph T. Abaya
Theses and Dissertations
The process of creating metal components through additive manufacturing is changing the way different industries can avoid the shortcomings of traditional metal production. Metals such as tungsten, molybdenum, and rhenium have many advantages for different applications, especially when alloyed together. In this study, an additively manufactured alloy containing 70% molybdenum, 25% tungsten, and 5% rhenium (70Mo-25W-5Re) is tested for its strength, ductility, hardness, and porosity. The 70Mo-25W-5Re alloy is printed through Laser Powder Bed Fusion (LPBF) under different conditions such as printing speed and printing atmosphere. Additionally, the effects of post printing heat treatment are conducted to understand the advantages …
Effects Of A Nitrogen And Hydrogen Build Atmosphere On The Properties Of Additively Manufactured Tungsten, Dana C. Madsen
Effects Of A Nitrogen And Hydrogen Build Atmosphere On The Properties Of Additively Manufactured Tungsten, Dana C. Madsen
Theses and Dissertations
Additively manufactured tungsten was printed in pure nitrogen, nitrogen-2.5% hydrogen, and nitrogen-5% hydrogen atmospheres as part of a 2^3 full factorial designed experiment and subjected to room temperature and high-temperature three-point-bend testing, chemical analysis, hardness testing, and microstructural imaging techniques. The pure nitrogen specimens exhibited the highest strength and ductility at both high temperature and room temperature. Chemical analysis showed a 2-8x reduction in compositional oxygen relative to unprocessed powder. Hardness values for all samples was between 306.8 and 361.5 HV1. It is proposed that adding hydrogen into the build atmosphere reduced the available energy density for tungsten melting by …
Critical Evaluation Of Construction Industry-Related Additive Manufacturing Research: A Scientometric Analysis, Tyler J. Brunjes
Critical Evaluation Of Construction Industry-Related Additive Manufacturing Research: A Scientometric Analysis, Tyler J. Brunjes
Theses and Dissertations
Review of construction-related AM literature is used to identify the advantages, challenges, and current trends of the research. Using a scientometric analysis of 522 bibliographic records, this research systematically analyzed construction related AM research to determine the key research areas and trends. Results showed that starting in 2015, the field has been growing at an exponential rate. Recent AM research focused on materials and reinforcement topics, which matched the most notable challenges of AM, which are material rheology, reinforcement, and lacking construction standards. This study provides an insight into AM research and identifies areas requiring more innovation before its commercial …
Design And Testing Of A Composite Compressor Rotor, Mauro Noel V. De Leon
Design And Testing Of A Composite Compressor Rotor, Mauro Noel V. De Leon
Theses and Dissertations
Additive manufacturing (AM) and molding are manufacturing methods known for building representations or replicas of conceptualized engine components, but was considered impractical for manufacturing operating engine components. More recent technology has rendered composite materials (combining high-temperature polymers and fiber reinforcement) capable of withstanding the temperature and structural requirements to compete with conventional turbomachinery metals. This study explores the application of several high-temperature polymers (ULTEM 9085, Onyx-Carbon fiber, and Epoxy-Carbon fiber) and their survivability in the operating conditions of a P400 Engine compressor. The tests conducted for this study determined their viability as compressor materials. This study required conducting tensile specimen …