A comprehensive study of the effect of scanning strategy on IN939 fabricated by powder bed fusion-laser beam

Date

2024-11-01

Author

Doğu, Merve Nur
Ozer, Seren
Yalçın, Mustafa Alp
Davut, Kemal
Obeidi, Muhannad Ahmed
Şimşir, Caner
Gu, Hengfeng
Teng, Chong
Brabazon, Dermot

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This study provides a comprehensive investigation into the effects of different scanning strategies on the material properties of IN939 fabricated using the PBF-LB process. The scanning strategies examined included alternating bi-directional scanning with rotation angles of 0°, 45°, 67°, and 90° between adjacent layers (named as shown), as well as alternating chessboard scanning with rotation angles of 67° and 90° (named as Q67° and Q90°). The results revealed that the 45° and 67° samples had the highest relative density, while the 0° and Q67° samples showed the highest average porosity. Moreover, various types of cracks, including solidification, solid-state, and oxide-induced cracks, were observed. Among the bi-directional scan samples, the 0° sample displayed the most extensive cracking and the highest σmax residual stress values in both XZ and XY planes. Conversely, the 45° and 67° samples exhibited fewer cracks. Notably, the lowest σmax residual stress in the XZ planes among the bi-directional scan samples was observed in the 67° sample. Additionally, microstructural analyses indicated differences in grain size and morphology, among the samples. Texture analysis indicated that the 0° and 90° samples exhibited strong cube textures, whereas the texture intensity weakened for the 45° and 67° samples. Moreover, the alternating chessboard scanning strategy led to rougher surfaces (higher Sa and Sz values) compared to the alternating bi-directional scanning strategy, regardless of the rotation angles. Furthermore, the microhardness values among the samples showed minimal variance, ranging between 321 ± 14 HV and 356± 7 HV.

Subject Keywords

Electron backscatter diffraction (EBSD), IN939, Microstructure, Powder bed fusion-laser beam (PBF-LB), Residual stress, Scanning strategy

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85207312401&origin=inward
https://hdl.handle.net/11511/112524

Collections

Department of Metallurgical and Materials Engineering, Article