Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based Superalloy
Hot cracking is a frequent and severe defect that occurs during laser additive manufacturing of superalloys. In this work, a pulsed-wave (PW) laser modulation process was employed to control the solidification microstructure and reduce the hot cracking susceptibility of laser additive manufactured c...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-11-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/14/12/1043 |
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| author | Xuanyu Liu Xianghui Xiao Wenjia Xiao Junbin Zeng Kuanfang He Hui Xiao |
| author_facet | Xuanyu Liu Xianghui Xiao Wenjia Xiao Junbin Zeng Kuanfang He Hui Xiao |
| author_sort | Xuanyu Liu |
| collection | DOAJ |
| description | Hot cracking is a frequent and severe defect that occurs during laser additive manufacturing of superalloys. In this work, a pulsed-wave (PW) laser modulation process was employed to control the solidification microstructure and reduce the hot cracking susceptibility of laser additive manufactured cobalt-based superalloy. The effects of continuous-wave (CW) and PW laser processing modes on the dendrite morphology, element segregation, eutectic phase, and hot cracking of fabricated Co-based superalloys were investigated. Optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to characterize the microstructural characteristics of samples. A two-color pyrometer was used to measure the molten pool temperature variation under different laser processing modes. The results show that coarse columnar dendrites, chain-like eutectic carbides, and hot cracks were observed in the CW sample. In contrast, the fine equiaxed crystals, discrete eutectic carbides, and low-level residual stresses were obtained to avoid hot cracks, owing to the high cooling rate and the periodic melting and solidification of the molten pool under the PW laser processing mode. This work provides a new method for controlling solidification structure and hot cracking of laser additive manufactured Co-based superalloy. |
| format | Article |
| id | doaj-art-5e4b73784ea648749a95dfdc6d7edf0a |
| institution | DOAJ |
| issn | 2073-4352 |
| language | English |
| publishDate | 2024-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj-art-5e4b73784ea648749a95dfdc6d7edf0a2025-08-20T02:53:34ZengMDPI AGCrystals2073-43522024-11-011412104310.3390/cryst14121043Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based SuperalloyXuanyu Liu0Xianghui Xiao1Wenjia Xiao2Junbin Zeng3Kuanfang He4Hui Xiao5Guangdong Provincial Key Laboratory of Industrial Intelligent Inspection Technology, Foshan University, Foshan 528000, ChinaGuangdong Provincial Key Laboratory of Industrial Intelligent Inspection Technology, Foshan University, Foshan 528000, ChinaGuangdong Provincial Key Laboratory of Industrial Intelligent Inspection Technology, Foshan University, Foshan 528000, ChinaGuangdong Provincial Key Laboratory of Industrial Intelligent Inspection Technology, Foshan University, Foshan 528000, ChinaGuangdong Provincial Key Laboratory of Industrial Intelligent Inspection Technology, Foshan University, Foshan 528000, ChinaGuangdong Provincial Key Laboratory of Industrial Intelligent Inspection Technology, Foshan University, Foshan 528000, ChinaHot cracking is a frequent and severe defect that occurs during laser additive manufacturing of superalloys. In this work, a pulsed-wave (PW) laser modulation process was employed to control the solidification microstructure and reduce the hot cracking susceptibility of laser additive manufactured cobalt-based superalloy. The effects of continuous-wave (CW) and PW laser processing modes on the dendrite morphology, element segregation, eutectic phase, and hot cracking of fabricated Co-based superalloys were investigated. Optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to characterize the microstructural characteristics of samples. A two-color pyrometer was used to measure the molten pool temperature variation under different laser processing modes. The results show that coarse columnar dendrites, chain-like eutectic carbides, and hot cracks were observed in the CW sample. In contrast, the fine equiaxed crystals, discrete eutectic carbides, and low-level residual stresses were obtained to avoid hot cracks, owing to the high cooling rate and the periodic melting and solidification of the molten pool under the PW laser processing mode. This work provides a new method for controlling solidification structure and hot cracking of laser additive manufactured Co-based superalloy.https://www.mdpi.com/2073-4352/14/12/1043laser additive manufacturingcobalt-based superalloylaser processing modessegregationeutectic carbideshot crack |
| spellingShingle | Xuanyu Liu Xianghui Xiao Wenjia Xiao Junbin Zeng Kuanfang He Hui Xiao Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based Superalloy Crystals laser additive manufacturing cobalt-based superalloy laser processing modes segregation eutectic carbides hot crack |
| title | Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based Superalloy |
| title_full | Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based Superalloy |
| title_fullStr | Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based Superalloy |
| title_full_unstemmed | Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based Superalloy |
| title_short | Microstructure Control and Hot Cracking Prevention During Laser Additive Manufacturing of Cobalt-Based Superalloy |
| title_sort | microstructure control and hot cracking prevention during laser additive manufacturing of cobalt based superalloy |
| topic | laser additive manufacturing cobalt-based superalloy laser processing modes segregation eutectic carbides hot crack |
| url | https://www.mdpi.com/2073-4352/14/12/1043 |
| work_keys_str_mv | AT xuanyuliu microstructurecontrolandhotcrackingpreventionduringlaseradditivemanufacturingofcobaltbasedsuperalloy AT xianghuixiao microstructurecontrolandhotcrackingpreventionduringlaseradditivemanufacturingofcobaltbasedsuperalloy AT wenjiaxiao microstructurecontrolandhotcrackingpreventionduringlaseradditivemanufacturingofcobaltbasedsuperalloy AT junbinzeng microstructurecontrolandhotcrackingpreventionduringlaseradditivemanufacturingofcobaltbasedsuperalloy AT kuanfanghe microstructurecontrolandhotcrackingpreventionduringlaseradditivemanufacturingofcobaltbasedsuperalloy AT huixiao microstructurecontrolandhotcrackingpreventionduringlaseradditivemanufacturingofcobaltbasedsuperalloy |