Thesis
Densification and properties evolution of stainless steel alloys fabricated by three-dimensional printing
Washington State University
Master of Science (MS), Washington State University
2009
Handle:
https://hdl.handle.net/2376/102140
Abstract
Solid Freeform Fabrication (SFF) techniques are novel manufacturing processes that fabricate parts directly from Computer-Aided Design model with layer-by-layer fashion in short lead time. Because of those characteristics, SFF have such advantages as great manufacturability for complex-shaped parts, short manufacturing lead time, and low manufacturing cost for some of SFF techniques. However, there are also disadvantages such as limited material selections, dimensional error, and low relative density of SFF processed parts. Among various SFF techniques, three-dimensional printing (3DP) has advantages of low manufacturing cost and short lead time over other SFF techniques such as stereolithography, fused deposition modeling and selective laser sintering. However, low density and mechanical properties of the 3DP products have been issues for 3DP technology to expand their applications. This study is aimed to investigate the effect of adding Si3N4 on the density and properties evolution of three-dimensional printing (3DP) processed 420 stainless steel (SS) parts. The final density, dimensional changes, and mechanical property have been studied for the samples after a series of sintering conditions. The contents of Si3N4 powder ranging between 0 and 15 wt% and the sintering temperature were varied in the experiments in order to understand the dependence of densification kinetics and properties changes on these process parameters. The experiments provide the evidence that the addition of Si3N4 can improve the densification kinetics of 420 SS significantly. The 420 stainless steel samples produced by 3DP with 12.5 wt% Si3N4 sintered at 1225 ºC for 6 hours yielded 95% relative density, 190GPa Young‟s modulus, and 500 Knoop microhardness without any major sample shape distortion. The results are promising in that the 3DP process can be used to yield the prototype almost equivalent to a real part with a full mechanical capacity.
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Details
- Title
- Densification and properties evolution of stainless steel alloys fabricated by three-dimensional printing
- Creators
- Yongha Kim
- Contributors
- Dave Kim (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525147501842
- Language
- English
- Resource Type
- Thesis