Thesis
Additive Manufacturing of Inconel 718 Monolithic, Bimetallic, and Metal Matrix Composite Structures to Improve Mechanical and Thermal Properties
Washington State University
Master of Science (MS), Washington State University
2023
DOI:
https://doi.org/10.7273/000005088
Abstract
The high degree of freedom and optimization that additive manufacturing offers has completely changed the manufacturing landscape in general due to the potential of creating highly tailored parts for many different applications. Metal additive manufacturing technology in this regard has shown tremendous process due to attributes such as extremely high resolutions, compositional freedom, the potential for multi-material structures, and the potential to create lattice (controlled porosity) structures. This work aims to utilize the advantages that metal additive manufacturing provides to improve the overall performance of nickel superalloy Inconel 718.The first work of this thesis aims to improve the weak thermal properties of IN718 by creating a bimetallic structure of IN718 and the tungsten-heavy alloy W-7Ni-3Fe. It was found that the thermal diffusivity and compression strength of pure IN718 were improved by 100%. Furthermore, the interface between the two materials was relatively large, with no defects observed.
The second work of this research aims to understand the unintentional contamination of a titanium alloy (Ti6Al4V) with different amounts of IN718 and how it affected the mechanical properties. Titanium and nickel are known to be incompatible due to the formation of very brittle intermetallic phases. It was found that a 2.5% addition of IN718 caused Ti6Al4V alloy to exhibit almost no plastic deformation and, therefore, would catastrophically fail. Also, although the alloy was premixed thoroughly, the resulting parts would show the uneven distribution of Nickel throughout. Furthermore, some printed parts would show visible cracking due to the contamination, but others would show no sign of defects and still exhibit decreased plastic deformation.
The third work in this thesis was to reinforce Inconel 718 with in situ formed TaC/NbC to obtain better mechanical and oxidation performance to allow use in more extreme applications. It was found that adding 4 wt% Ta and 1% wt% SiC to Inconel 718 improved the compressive yield strength by 22.4% (with standard Inconel 718 heat treatment) and reduced the max oxidation mass gain by 62%. Furthermore, this composition responded well to the standard Inconel 718 heat treatment and contained uniform spherical distributions of TaC/NbC.
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Details
- Title
- Additive Manufacturing of Inconel 718 Monolithic, Bimetallic, and Metal Matrix Composite Structures to Improve Mechanical and Thermal Properties
- Creators
- Cory Groden
- Contributors
- Amit Bandyopadhyay (Advisor)Susmita Bose (Committee Member)David Field (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 81
- Identifiers
- 99901019838101842
- Language
- English
- Resource Type
- Thesis