Toward the Repair of Components via Additive Manufacturing: Process-Structure-Property Relationships in Single Beads and Patches

Open Access
Author:
Kistler, Nathan Allen
Graduate Program:
Materials Science and Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 16, 2016
Committee Members:
  • Allison Michelle Beese, Thesis Advisor
  • Edward William Reutzel, Committee Member
  • Robert Allen Kimel, Committee Member
  • Abdalla Ramadan Nassar, Committee Member
Keywords:
  • Additive Manufacturing
  • Ti-6Al-4V
  • Inconel 718
  • Directed Energy Deposition
  • Laser Cladding
  • Laser-Material Interaction
Abstract:
This thesis aims to generate an increased understanding of the directed energy deposition of two different materials: Inconel® 718 and Ti-6Al-4V. In order to complete a successful build using directed energy deposition, one must first completely understand the microstructure, mechanical properties, and dimensions of a single bead. Therefore, exhaustive studies were completed on Ti-6Al-4V and Inconel® 718 bead-on-plate deposits to study the impact processing parameters (i.e., laser power, processing speed, and working distance) had on the micro and macrostructure, microhardness in the deposit and underlying substrate, and the bead geometry (i.e., width, height, and angle of repose). The geometry of the Ti-6Al-4V single beads were used to complete Ti-6Al-4V patches to understand the effect different repair conditions had on the microstructure, microhardness, and porosity. Lastly, single bead-on-plate measurements were compared to full builds to elucidate the affect adjacently deposited beads had on the microstructure and microhardness.