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Characterization of Anisotropic Mechanical Performance of As-Built Additively Manufactured Metals

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Date Issued:
2018
Abstract/Description:
Additive manufacturing (AM) technologies use a 3D Computer Aided Design (CAD) model to develop a component through a deposition and fusion layer process, allowing for rapid design and geometric flexibility of metal components, for use in the aerospace, energy and biomedical industries. Challenges exist with additive manufacturing that limits its replacement of conventional manufacturing techniques, most especially a comprehensive understanding of the anisotropic behavior of these materials and how it is reflected in observed tensile, torsional and fatigue mechanical responses. As such, there is a need to understand how the build orientation of as-built additively manufactured metals, affects mechanical performance (e.g. monotonic and cyclic behavior, cyclically hardening/softening behavior, plasticity effects on fatigue life etc.); and to use constitutive modeling to both support experimental findings, and provide approximations of expected behavior (e.g. failure surfaces, monotonic and cyclic response, correlations between tensile and fatigue properties), for orientations and experiments not tested, due to the expensive cost associated with AM. A comprehensive framework has been developed to characterize the anisotropic behavior of as-built additively manufactured metals (i.e. Stainless Steel GP1 (SS GP1), similar in chemical composition to Stainless Steel 17-4PH), through a series of mechanical testing, microscopic evaluation and constitutive modeling, which were used to identify a reduced specimen size for characterizing these materials. An analysis of the torsional response of additively manufactured Inconel 718 has been performed to assess the impact of build orientation and as-built conditions on the shearing behavior of this material. Experimental results from DMLS SS GP1 and AM Inconel 718 from literature were used to constitutively model the material responses of these additively manufactured metals. Overall, this framework has been designed to serve as standard, from which build orientation selection can be used to meet specific desired industry requirements.
Title: Characterization of Anisotropic Mechanical Performance of As-Built Additively Manufactured Metals.
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Name(s): Siddiqui, Sanna, Author
Gordon, Ali, Committee Chair
Raghavan, Seetha, Committee CoChair
Bai, Yuanli, Committee Member
Sohn, Yongho, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2018
Publisher: University of Central Florida
Language(s): English
Abstract/Description: Additive manufacturing (AM) technologies use a 3D Computer Aided Design (CAD) model to develop a component through a deposition and fusion layer process, allowing for rapid design and geometric flexibility of metal components, for use in the aerospace, energy and biomedical industries. Challenges exist with additive manufacturing that limits its replacement of conventional manufacturing techniques, most especially a comprehensive understanding of the anisotropic behavior of these materials and how it is reflected in observed tensile, torsional and fatigue mechanical responses. As such, there is a need to understand how the build orientation of as-built additively manufactured metals, affects mechanical performance (e.g. monotonic and cyclic behavior, cyclically hardening/softening behavior, plasticity effects on fatigue life etc.); and to use constitutive modeling to both support experimental findings, and provide approximations of expected behavior (e.g. failure surfaces, monotonic and cyclic response, correlations between tensile and fatigue properties), for orientations and experiments not tested, due to the expensive cost associated with AM. A comprehensive framework has been developed to characterize the anisotropic behavior of as-built additively manufactured metals (i.e. Stainless Steel GP1 (SS GP1), similar in chemical composition to Stainless Steel 17-4PH), through a series of mechanical testing, microscopic evaluation and constitutive modeling, which were used to identify a reduced specimen size for characterizing these materials. An analysis of the torsional response of additively manufactured Inconel 718 has been performed to assess the impact of build orientation and as-built conditions on the shearing behavior of this material. Experimental results from DMLS SS GP1 and AM Inconel 718 from literature were used to constitutively model the material responses of these additively manufactured metals. Overall, this framework has been designed to serve as standard, from which build orientation selection can be used to meet specific desired industry requirements.
Identifier: CFE0007097 (IID), ucf:52883 (fedora)
Note(s): 2018-05-01
Ph.D.
Engineering and Computer Science, Mechanical and Aerospace Engineering
Doctoral
This record was generated from author submitted information.
Subject(s): Transversely Isotropic -- Direct Metal Laser Sintering -- Selective Laser Melting -- Inconel 718 -- Stainless Steel 17-4PH -- Stainless Steel GP1 -- Anisotropic -- Elastic Constants -- Chaboche -- Ramberg-Osgood -- Hahn Discontinuous Yielding -- Luder Bands -- Low Cycle Fatigue -- Tension -- Torsional Fatigue -- Torsion -- Mean Stress Fatigue -- Progressive Amplitude Fatigue -- Rockwell Hardness -- Hill Yield Criterion -- Kinematic Hardening -- Surface Roughness -- Microstructure of Additively Manufactured Materials -- Fracture Mechanics -- Constitutive Modeling -- Reduced test specimen -- Shear Modulus -- Poisson's Ratio -- Build Orientation -- Failure Surfaces
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0007097
Restrictions on Access: public 2018-05-15
Host Institution: UCF

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