|About this Abstract
||Materials Science & Technology 2019
||Additive Manufacturing of Metals: Microstructure and Material Properties of Nickel-based Alloys
||Effects of Laser Processing Parameters and Build Orientation on the Surface Roughness and High-cycle Fatigue Life of Inconel 718 Manufactured Using Laser Powder Bed Fusion
||Dillon Watring, Kristen C Carter, Dustin Crouse, Ashley Spear
|On-Site Speaker (Planned)
The relationships among AM processing parameters, surface roughness, and high-cycle fatigue life were investigated. Inconel 718 fatigue specimens were fabricated using laser powder bed fusion according to 25 different sets of processing parameters varying laser power, scan speed, layer thickness, and build orientation. Surface roughness and high-cycle fatigue life were measured. Two processing-parameter metrics were observed to drive the high-cycle fatigue life: build orientation and laser-energy density. Build orientation had a larger influence on fatigue life due to the relationship between build orientation and surface roughness. For a fixed build orientation, the laser-energy density, outside of the optimal range, had detrimental effects on the fatigue life due to sub-surface defects. Specifically, fractography analysis showed that sub-surface defects consisted of unmelted/unfused regions at lower laser-energy densities and keyhole porosities and secondary cracking at higher laser-energy densities. Based on these findings, guidelines are offered to improve fatigue life of AM Inconel 718.
||Planned: At-meeting proceedings