Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior
The equiatomic CoCrFeNiMn high-entropy alloy (HEA) possesses excellent properties including exceptional strength–ductility synergy, high corrosion resistance, and good thermal stability. Selective laser melting (SLM) additive manufacturing facilitates the convenient fabrication of the CoCrFeNiMn HEA...
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MDPI AG
2022-12-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/23/8560 |
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| author | Jianrui Zhang Yabin Yan Bo Li |
| author_facet | Jianrui Zhang Yabin Yan Bo Li |
| author_sort | Jianrui Zhang |
| collection | DOAJ |
| description | The equiatomic CoCrFeNiMn high-entropy alloy (HEA) possesses excellent properties including exceptional strength–ductility synergy, high corrosion resistance, and good thermal stability. Selective laser melting (SLM) additive manufacturing facilitates the convenient fabrication of the CoCrFeNiMn HEA parts with complex geometries. Here, the SLM process optimization was conducted to achieve a high relative density of as-built CoCrFeNiMn HEA bulks. The mechanisms of process-induced defects and process control were elucidated. The microscale mechanical behaviors were analyzed through in situ scanning electron microscopy observation during the compression tests on micro-pillars of the as-built HEA. The stress–strain characteristics by repeated slip and mechanism of “dislocation avalanche” during the compression of micro-pillars were discussed. The high-cycle fatigue tests of the as-built HEA were performed. It was found that a large number of nano-twins were induced by the fatigue, causing a non-negligible cycle softening phenomenon. The effects of promoted ductility due to the fatigue-induced nano-twins were illustrated. This work has some significance for the engineering application of the SLM additively manufactured CoCrFeNiMn HEA parts. |
| first_indexed | 2024-03-09T17:41:59Z |
| format | Article |
| id | doaj.art-c39a221bf03c4403874367f2d8012a9d |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T17:41:59Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-c39a221bf03c4403874367f2d8012a9d2023-11-24T11:30:19ZengMDPI AGMaterials1996-19442022-12-011523856010.3390/ma15238560Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue BehaviorJianrui Zhang0Yabin Yan1Bo Li2School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaThe equiatomic CoCrFeNiMn high-entropy alloy (HEA) possesses excellent properties including exceptional strength–ductility synergy, high corrosion resistance, and good thermal stability. Selective laser melting (SLM) additive manufacturing facilitates the convenient fabrication of the CoCrFeNiMn HEA parts with complex geometries. Here, the SLM process optimization was conducted to achieve a high relative density of as-built CoCrFeNiMn HEA bulks. The mechanisms of process-induced defects and process control were elucidated. The microscale mechanical behaviors were analyzed through in situ scanning electron microscopy observation during the compression tests on micro-pillars of the as-built HEA. The stress–strain characteristics by repeated slip and mechanism of “dislocation avalanche” during the compression of micro-pillars were discussed. The high-cycle fatigue tests of the as-built HEA were performed. It was found that a large number of nano-twins were induced by the fatigue, causing a non-negligible cycle softening phenomenon. The effects of promoted ductility due to the fatigue-induced nano-twins were illustrated. This work has some significance for the engineering application of the SLM additively manufactured CoCrFeNiMn HEA parts.https://www.mdpi.com/1996-1944/15/23/8560selective laser meltinghigh-entropy alloysCoCrFeNiMnprocess optimizationmicroscale mechanical propertiesfatigue |
| spellingShingle | Jianrui Zhang Yabin Yan Bo Li Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior Materials selective laser melting high-entropy alloys CoCrFeNiMn process optimization microscale mechanical properties fatigue |
| title | Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior |
| title_full | Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior |
| title_fullStr | Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior |
| title_full_unstemmed | Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior |
| title_short | Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior |
| title_sort | selective laser melting slm additively manufactured cocrfenimn high entropy alloy process optimization microscale mechanical mechanism and high cycle fatigue behavior |
| topic | selective laser melting high-entropy alloys CoCrFeNiMn process optimization microscale mechanical properties fatigue |
| url | https://www.mdpi.com/1996-1944/15/23/8560 |
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