Abstract
Inconel 738 LC samples were fabricated using laser powder bed fusion under continuous-wave and pulsed-wave modes. Microstructure, surface quality and mechanical properties were compared to evaluate the printing quality between these 2 laser beam modes. The results show that the application of pulsed wave could effectively eliminate cracking in the as-fabricated sample, despite 0.046% porosity generated. Further microstructure analysis revealed that the refinement of grains by the pulsed-wave laser beam was the main contributor in eliminating the cracks. And this refinement was ascribed to the higher cooling rate under the discontinuous radiation of laser beam proofed by the numerical simulation. And the pore formation was related to Rayleigh instability and residual bubbles in the sample under the pulsed-wave mode, while pores were less detrimental to the mechanical properties than cracks. Therefore, the part under the pulsed-wave mode exhibited superior mechanical performance compared to that under the continuous-wave mode.
Original language | English |
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Pages (from-to) | 45-57 |
Number of pages | 13 |
Journal | Journal of Materials Science and Technology |
Volume | 90 |
Early online date | 24 Apr 2021 |
DOIs | |
Publication status | Published - 10 Nov 2021 |
Bibliographical note
Funding Information:This work is financially supported by National Natural Science Foundation of China (No. 91860131 and No. 52074157 ), National Key Research and Development Program of China (No. 2017YFB0702901), Shenzhen Science and Technology Innovation Commission under the Projects (No. JCYJ20170817111811303, No. KQTD20170328154443162 and ZDSYS201703031748354) and joint Ph.D. program between SUSTech and UoB (No. FEFE/GAS1792).
Publisher Copyright:
© 2021
Keywords
- Continuous-wave mode
- Defect generation
- Laser powder bed fusion
- Nickel-based superalloy
- Pulsed-wave mode
ASJC Scopus subject areas
- Ceramics and Composites
- Mechanics of Materials
- Mechanical Engineering
- Polymers and Plastics
- Metals and Alloys
- Materials Chemistry