Abstract
The causes of cracking during thermal post-processing of laser powder bed fabricated (LPBF) CM247LC Ni-superalloy have been examined. Micro-hardness measurements and microstructural analyses were undertaken following short aging heat treatments around the phase transformation temperatures identified by Differential Scanning Calorimetry (DSC) analysis of the as-built condition. Results showed a steep increase in cracking density in the samples between 450 °C and 600 °C, which corresponded to changes in the microstructure, hardness, and elastic modulus. A combination of ductility dip cracking and strain age cracking mechanisms were identified as the primary causes of cracking in LPBF CM247LC following post-build thermal treatments. The results of this work shed light on the relationship between the heat treatment temperatures and the onset of post-build cracking, and could help develop post-LPBF heat treatments for high γ′ Ni-superalloys.
Original language | English |
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Article number | 107793 |
Journal | Materials and Design |
Volume | 174 |
Early online date | 10 Apr 2019 |
DOIs | |
Publication status | Published - 15 Jul 2019 |
Keywords
- Laser powder bed fusion
- Mechanical properties
- Microstructure
- Nickel superalloys
ASJC Scopus subject areas
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering