Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Mechanical Engineering
Synthesis And Characterization Of Tin (Sn) Incorporated Ga2o3, Guillermo Nicolas Gutierrez
Synthesis And Characterization Of Tin (Sn) Incorporated Ga2o3, Guillermo Nicolas Gutierrez
Open Access Theses & Dissertations
In this work, we report on the synthesis, characterization of tin (Sn) incorporated gallium oxide Ga2O3 compounds, also included in this work is the effect of tin concentration related to the optical and electrochemical properties. The Sn incorporation into Ga2O3 creates a significant reduction in the bandgap and causes a nonlinear optical activity as the concentration varies. Substantial investigation performed to the structure, phase, and morphology of the mixed compounds governed by the stoichiometry equation Ga2−2xSnxO3-ɗ indicates that the Sn incorporation from 0.00 ≤ x ≤ 0.30 has a significant effect on these properties. To synthesize the Ga-Sn-O compounds a …
Phase Transformation And Strain Hardening Mechanisms In Advanced Engineering Steels, Hangyu Dong
Phase Transformation And Strain Hardening Mechanisms In Advanced Engineering Steels, Hangyu Dong
Open Access Theses & Dissertations
Strain hardening and associated deformation mechanisms play a determining role in the performance of metallic materials. The objective of the doctoral research was to explore and fundamentally understand the strain hardening mechanisms in the next generation of advanced engineering steels. Two main work hardening mechanisms, notably, twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP)) were identified that governed strength and ductility. In the nanograined austenitic steel with high strength-high ductility combination, processed by the novel phase reversion concept, twinning-induced plasticity (TWIP) was the governing deformation mechanism and contributed to good ductility. In striking contrast, transformation-induced plasticity (TRIP) was the deformation mechanism …
Mechanical Properties And Microstructure Evolution Of Thermally Treated Laser Powder Bed Fusion Alsi10mg, Jorge Merino-Gomez
Mechanical Properties And Microstructure Evolution Of Thermally Treated Laser Powder Bed Fusion Alsi10mg, Jorge Merino-Gomez
Open Access Theses & Dissertations
The optimization of mechanical properties with thermal postprocessing treatments was investigated in this study across a wide variety of variants. The relationship between heat treatments and the impacts on the mechanical properties and microstructure of printed materials is a crucial part of additive manufacturing. As a result, the current paper provides a comprehensive overview of postprocess heat treatments for Laser Powder Bed Fusion fabricated AlSi10Mg alloy, including stress relief anneals at 190 and 285 degrees Celsius for 2 hours, hot isostatic pressing at 515 degrees Celsius for 3 hours, hot isostatic pressing + T6 treatment for 6 hours, and final …
Post Processing Of Electron Beam Melted Ti-6al-4v And Binder Jetted 17-4 Stainless Steel, Ahmad Omar Abu-Issa
Post Processing Of Electron Beam Melted Ti-6al-4v And Binder Jetted 17-4 Stainless Steel, Ahmad Omar Abu-Issa
Open Access Theses & Dissertations
An extensive assortment of HIP parameters have been altered on EBM fabricated Ti-6Al-4V and have shown that cooling rates of 103 oC/min from temperatures above and below the beta transus produced acicular alpha-prime martensite characteristic elongations < 10 %. Optimum yield strength (0.9 GPa), UTS (1.0 GPa) and elongation (~14 %) were achieved for slow cooling (at 102 oC/min) from 850 oC HIP which produced a dense, Widmanstatten alpha structure within the retained, as-fabricated columnar grains by alpha-prime decomposition. These results suggest that manipulation of AM process parameters to produce a small-grain, equiaxed microstructure, HIPed below the beta transus and slow cooled, will have a wide range of superior, isotropic mechanical properties corresponding to a Widmanstatten alpha microstructure within the equiaxed grains. Also, Binder Jetting printing parameters for differing PSD's of low-cost water-atomized 17-4 Stainless Steel were optimized in order to produce high dense parts. Densities ranging from 94-97.5% were achieved, and issues of inhomogeneous porosity were addressed using a fumed silica flow additive.
Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza
Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza
Open Access Theses & Dissertations
The following body of work encompasses the synThesis, upscaling, additive manufacturing, and characterization of microspheres as functional fillers incorporated into polymer syntactic foams. Synthesizing microspheres permits control over morphology, dispersion of particles, and size while the use of direct write manufacturing allowed for the controllability of filler orientation. Two different syntactic foams were developed from similar methodologies: (1) a silicone syntactic foam (2) epoxy syntactic foam. The silicone epoxy foam showed an increasing in damping and elastic modulus. The epoxy syntactic foams showed an enhanced thermal and electrical properties.