Abstract
An investigation was conducted to understand how different parameters, namely laser power, scan speed and hatch spacing, influence the printing qualities, i.e. surface roughness, porosity and crack density of the nickel-based superalloy Inconel 738LC during laser powder bed fusion. Insufficient overlap, Plateau–Rayleigh instability and Marangoni convection were identified and characterized as the factors that could deteriorate the surface quality of as-built IN738LC parts. Two leading causes of pore were determined by metallographic analysis and computed tomography as lack of fusion and keyhole, which were attributed to different energy input densities. Crack density was measured by metallographic observation. Residual stress and the time for solidification of melt were identified as the key factors that affected the crack density. Finally, the relationships between the printing qualities and volume energy density were established by regression analysis, and the VED of ∼ 48 J/mm3 was optimal for fabricating IN738LC in the LPBF process
Original language | English |
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Article number | 116788 |
Number of pages | 17 |
Journal | Journal of Materials Processing Technology |
Volume | 285 |
Early online date | 1 Jun 2020 |
DOIs | |
Publication status | Published - Nov 2020 |
Keywords
- Crack density
- Laser powder bed fusion
- Nickel-Based superalloy
- Porosity
- Processing parameters
- Surface roughness
ASJC Scopus subject areas
- Ceramics and Composites
- Computer Science Applications
- Metals and Alloys
- Industrial and Manufacturing Engineering