Fracture Behavior of Stress Relieved Laser-Powder Bed Fusion of Inconel 625
Open Access
Author:
Vailhe, Madeline
Area of Honors:
Materials Science and Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Allison Michelle Beese, Thesis Supervisor Robert Allen Kimel, Thesis Honors Advisor
Keywords:
Additive Manufacturing Laser Powder Bed Fusion Inconel 625 Delta Phase Heat Treatment Metal Materials Materials Science and Engineering
Abstract:
This study includes an investigation into the structure-property relationships and mechanical behavior of laser powder bed fusion (LPBF) printed Inconel 625 (IN625) with a post-processing heat treatment. Compared to as-built specimens, the stress relieved microstructure included about 10 vol% δ phase needle-like precipitates. Microstructure imaging also revealed elongated grains that contributed to direction-dependent mechanical behavior revealed in uniaxial tension testing. It was found the engineering strain to failure in the vertical build direction was 32% higher than in the horizontal or perpendicular build direction. Notched tension testing also created a multiaxial stress state that with differing stress triaxiality revealed the stress-state dependent behavior. Finite element analysis was then used to create a model and used to simulate the mechanical behavior of the material.
