Inconel 718 is a nickel-based superalloy with a series of superior properties, such as high strength, creep-resistance, and corrosion-resistance. Additive manufacturing (AM) is appealing to Inconel 718 because of its near-net-shape production capability to circumvent poor machinability. However, AM parts are prone to detrimental porosity, reducing their fatigue resistance. Thus, further understanding of AM fatigue behavior is required before widespread industrial use. The microstructural and fatigue properties of heat treated AM Inconel 718, produced using Laser Engineered Net Shaping (LENS™), are evaluated at room and elevated temperatures. Fully reversed, strain-controlled fatigue tests were performed on cylindrical specimens at strain amplitudes of 0.001 to 0.01 mm/mm. Fracture surfaces were inspected using a scanning electron microscope (SEM). Heat treatment caused initial dendritic microstructure to mostly re-form into an equiaxed grain structure. AM specimens experienced reduced fatigue life in testing as compared to wrought material due to inclusions or pores near the surface.
|Advisor:||Stone, Tonya W., Shamsaei, Nima|
|Commitee:||Doude, Haley R., Priddy, Matthew W.|
|School:||Mississippi State University|
|School Location:||United States -- Mississippi|
|Source:||MAI 56/04M(E), Masters Abstracts International|
|Keywords:||Additive manufacturing, Fatigue, Inconel 718, Microstructure|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be