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

Abstract

This effort explores the influence of four key process parameters and scan strategies on the formation and characteristics of porosity distributions in additive manufacturing (AM) material. Then, based on the porosity distributions observed via nondestructive 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 prior investigations. The connections made through the work presented herein link AM processing to potential design requirement which will facilitate faster, safer design efforts for implementation of AM components into structurally critical applications.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2020
Accession Number
AD1156522

Entities

People

  • Luke Sheridan

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Biomedical
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Additive Manufacturing
  • Chemistry
  • Detectors
  • Elastic Properties
  • Electron Beam Melting
  • Experimental Design
  • Fabrication
  • Manufacturing
  • Materials
  • Materials Science
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Selective Laser Melting
  • Selective Laser Sintering
  • Test Methods
  • X-Ray Computed Tomography

Fields of Study

  • Materials science

Readers

  • Adaptive Control and Estimation with Uncertainty in Dynamic Systems.
  • Materials Science (Mechanical Engineering).
  • Software Engineering