Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718

Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718

Bibliographic Details
Main Author: Sheridan, Luke C.
Language:English
Published: Wright State University / OhioLINK 2020
Subjects:
Mechanical Engineering
Mechanics
Materials Science
Metallurgy
Fatigue
Alloy 718
Nickel-Based Superalloy
Additive Manufacturing
Laser Powder Bed Fusion
Compliance
Porosity
Crack Growth
Crack Initiation
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=wright1588254461821575
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-wright15882544618215752021-08-03T07:14:50Z Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718 Sheridan, Luke C. Mechanical Engineering Mechanics Materials Science Metallurgy Fatigue Alloy 718 Nickel-Based Superalloy Additive Manufacturing Laser Powder Bed Fusion Compliance Porosity Crack Growth Crack Initiation In many structural applications void-like defects cause significant performance debits which call for component redesign or post-processing to account for or remove the defects. For laser powder bed fusion (LPBF) processes, it has been shown that many of these features and their size and shape characteristics are controllable through LPBF process parameter manipulation. For design efforts, however, it is necessary to understand the direct influences of processing on the formation of porosity and the role that individual pores and porosity distributions have on the properties and performance of AM components. Additionally, design criteria must be established to facilitate implementation of AM components into structurally critical applications. To this end, the investigations that have been performed here relate the AM material processing of alloy 718 to the pore structure, crack growth properties and fatigue performance. This dissertation first explores the influence of four key process parameters and scan strategies on the formation and characteristics of porosity distributions in AM material. Then, based on the porosity distributions observed via non-destructive inspection techniques, a crack-growth based life prediction method was developed to accurately predict fatigue lives of AM components. Additionally, fatigue limit models were modified based on experimental data to explore the interactions of defect size and applied stress with respect to both finite and "infinite" fatigue life which enables defect tolerant design for components manufactured via AM. Finally, a novel compliance-based method for crack initiation detection was developed and used to assess some of the assumptions made in the prior investigations. The connections made through the work presented herein link AM processing to potential design requirements which will facilitate faster, safer design efforts for implementation of AM components into structurally critical applications. 2020-05-18 English text Wright State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=wright1588254461821575 http://rave.ohiolink.edu/etdc/view?acc_num=wright1588254461821575 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Mechanical Engineering
Mechanics
Materials Science
Metallurgy
Fatigue
Alloy 718
Nickel-Based Superalloy
Additive Manufacturing
Laser Powder Bed Fusion
Compliance
Porosity
Crack Growth
Crack Initiation
spellingShingle Mechanical Engineering
Mechanics
Materials Science
Metallurgy
Fatigue
Alloy 718
Nickel-Based Superalloy
Additive Manufacturing
Laser Powder Bed Fusion
Compliance
Porosity
Crack Growth
Crack Initiation
Sheridan, Luke C.
Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718
author Sheridan, Luke C.
author_facet Sheridan, Luke C.
author_sort Sheridan, Luke C.
title Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718
title_short Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718
title_full Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718
title_fullStr Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718
title_full_unstemmed Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718
title_sort primary processing parameters and their influence on porosity and fatigue life of additively manufactured alloy 718
publisher Wright State University / OhioLINK
publishDate 2020
url http://rave.ohiolink.edu/etdc/view?acc_num=wright1588254461821575
work_keys_str_mv AT sheridanlukec primaryprocessingparametersandtheirinfluenceonporosityandfatiguelifeofadditivelymanufacturedalloy718
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