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Synergistic Strategies In Sinter-Based Material Extrusion (Mex) 3d Printing Of Copper: Process Development, Product Design, Predictive Maps And Models., Kameswara Pavan Kumar Ajjarapu Dec 2023

Synergistic Strategies In Sinter-Based Material Extrusion (Mex) 3d Printing Of Copper: Process Development, Product Design, Predictive Maps And Models., Kameswara Pavan Kumar Ajjarapu

Electronic Theses and Dissertations

3D printing pure copper with high electrical conductivity and exceptional density has long been challenging. While laser-based additive manufacturing technologies suffered due to copper's highly reflective nature towards laser beams, parts printed via binder-assisted technologies failed to reach over 90% IACS (International Annealed Copper Standard), electrical conductivity. Although promising techniques such as binder jetting, filament, and pellet-based 3D printing that can print copper exist, they however still face difficulties in achieving both high sintered densities and electrical conductivity values. This is due to a lack of comprehensive understanding of property evolution from green to sintered states and the strategies that …


Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh May 2020

Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh

Electronic Theses and Dissertations

Additive manufacturing (AM) is at the mainstream to cater the needs for rapid tooling and small-scale part production. The metal AM of complex geometries is widely accepted and promoted in the industry. While several metal AM technologies exist and are matured to a level where expectation in terms of design and properties are possible to realize. But the metal AM suffers from the heavy expense to acquire equipment, isotropic property challenges, and potential hazards to work with loose reactive metal powder. With this motivation, the dissertation aims to develop the fundamental aspects to print metal parts with bound Ti-6Al-4V powder …


A Study On Ultrasonic Energy Assisted Metal Processing : Its Correeltion With Microstructure And Properties, And Its Application To Additive Manufacturing., Anagh Deshpande May 2019

A Study On Ultrasonic Energy Assisted Metal Processing : Its Correeltion With Microstructure And Properties, And Its Application To Additive Manufacturing., Anagh Deshpande

Electronic Theses and Dissertations

Additive manufacturing or 3d printing is the process of constructing a 3-dimensional object layer-by-layer. This additive approach to manufacturing has enabled fabrication of complex components directly from a computer model (or a CAD model). The process has now matured from its earlier version of being a rapid prototyping tool to a technology that can fabricate service-ready components. Development of low-cost polymer additive manufacturing printers enabled by open source Fused Deposition Modeling (FDM) printers and printers of other technologies like SLA and binder jetting has made polymer additive manufacturing accessible and affordable. But the metal additive manufacturing technologies are still expensive …


Process-Property-Microstructure Relationships In Laser-Powder Bed Fusion Of 420 Stainless Steel., Subrata Deb Nath Dec 2018

Process-Property-Microstructure Relationships In Laser-Powder Bed Fusion Of 420 Stainless Steel., Subrata Deb Nath

Electronic Theses and Dissertations

Laser-powder bed fusion (L-PBF) is an additive manufacturing technique for fabricating metal components with complex design and customized features. However, only a limited number of materials have been widely studied using L-PBF. AISI 420 stainless steel, an alloy with a useful combination of high strength, hardness, and corrosion resistance, is an example of one such material where few L-PBF investigations have emerged to date. In this dissertation, L-PBF experiments were conducted using 420 stainless steel powders to understand the effects of chemical composition, particle size distribution and processing parameters on ensuing physical, mechanical and corrosion properties and microstructure in comparison …


Material-Process-Property Relationships Of 17-4 Stainless Steel Fabricated By Laser-Powder Bed Fusion Followed By Hot Isostatic Pressing., Harish Irrinki Aug 2018

Material-Process-Property Relationships Of 17-4 Stainless Steel Fabricated By Laser-Powder Bed Fusion Followed By Hot Isostatic Pressing., Harish Irrinki

Electronic Theses and Dissertations

17-4 PH stainless steel is commonly used in medical, tooling, automotive, chemical and aerospace industries due to its excellent strength and corrosion properties. Additive manufacturing processes such as laser-powder bed fusion (L-PBF) have gained attention and importance due to the potential to produce complex-shaped three-dimensional parts for various industries. In order to manufacture three-dimensional components from 17-4 PH stainless steel powder using L-PBF, it is critical for design and manufacturing engineers to have an awareness of various material options and corresponding processing and post-processing conditions to obtain useful mechanical properties from the process. The goal of this dissertation is to …


Microstructure, Quasi-Static, And High-Strain Rate Dynamic Characterization Of Metakaolin And Fly Ash Based Geopolymers For Structural Applications, Damian Lee Stoddard Jan 2014

Microstructure, Quasi-Static, And High-Strain Rate Dynamic Characterization Of Metakaolin And Fly Ash Based Geopolymers For Structural Applications, Damian Lee Stoddard

Electronic Theses and Dissertations

Geopolymers are a class of rapid setting cementing systems that have been used as mortar or additives in concrete mixes to improve properties. Several types of geopolymer systems such as metakaolin and fly ash based geopolymers are widely used, and are available in different mixture proportions [1, 2]. Metakaolin (Al2Si2O7), a dehydroxylated form of Kaolinite (Al2Si2O5(OH)4) clay readily available from many sources, provides several benefits whenadded to a concrete mix design or used as a mortar system, including durability, freeze/thaw, acid resistance, and high temperature resistance [3]. Class F fly ash-based mortar geopolymers provide added fire retardation, reduces crack formation, …