Thesis
Investigation of the microstructure and mechanical properties in additive manufactured Inconel 718 by direct metal laser sintering (DMLS) system
Master of Science (M.S.), Drexel University
Jan 2016
DOI:
https://doi.org/10.17918/etd-6702
Abstract
Additive Manufacturing (AM) has evolved since its inception around the 1970s. This type of manufacturing essentially builds a part by fusing material powder with the use of a laser or electron beam. Certain processing parameters, such as the scanning speed of the laser, the overlap rate of melt tracks and the incremental layer height control the final structure of the part and thus their mechanical properties. Prototype and single use parts were at the forefront of use for AM, however, in recent years the technology has developed to take the next step into production parts for use in real-world applications. One common material used for high temperature and corrosive environments is Inconel 718. This material is a nickel-based alloy typically used in different areas of the aerospace and energy industries. The mechanical properties of Inconel 718 produced through AM methods have proven to not match those produced through conventional means. Since these processed are new to the manufacturing world, it is important to understand where the loss in properties come from but also, and perhaps more importantly, how to make improvements. In this study, standard processing methods were implemented and their effects examined from changes of microstructure to mechanical properties. Generally, a textured columnar microstructure (of varying sizes) developed from the building process. A typical solution and aging treatment used for wrought Inconel 718 produced a non-normal precipitate structure which led to high mechanical strengths. By way of Hot Isostatic Pressing, the microstructure under goes a reecrystallization process, altering some of the properties including texture and , with it the elastic modulus for the better, while other properties such as hardness and yield strength were diminished.
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Details
- Title
- Investigation of the microstructure and mechanical properties in additive manufactured Inconel 718 by direct metal laser sintering (DMLS) system
- Creators
- Bryton L. Farber - DU
- Contributors
- Mitra Taheri (Advisor) - Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xiv, 107 pages
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- Materials (Science and) Engineering (Metallurgical Engineering) (1970-2026); College of Engineering (1970-2026); Drexel University
- Other Identifier
- 6702; 991014632188204721