{"title":"高熵合金的形变诱导非晶化和纳米晶化","authors":"Bo Li, Nan Zi, Jiayin Zhao, Kaisheng Ming","doi":"10.1016/j.scriptamat.2025.116783","DOIUrl":null,"url":null,"abstract":"<div><div>High-entropy alloys (HEAs) with exceptional cryogenic strength and toughness are pivotal for extreme engineering applications, yet their deformation mechanisms at ultra-low temperatures remain incompletely understood. Here, we report two types of deformation-induced amorphization and nanocrystallization within amorphous bands in a CrMnFeCoNi HEA under tensile loading at 4.2 K. Unlike dislocation-driven amorphization that forms nanoscale amorphous bands (nano-ABs, >5 nm thick), supra-nanometer amorphous bands (SN-ABs, <5 nm thick) emerge via lattice distortion under extreme localized shear localization rather than dislocation accumulation. Concurrently, localized heating from plastic deformation triggers nanocrystallization within nano-ABs, generating randomly oriented nanograins. The amorphization and nanocrystallization are expected to provide an extra toughening mechanism for HEAs by dissipating strain energy and impeding shear localization. Crucially, we establish a microstructural link between low-temperature serrated flow behavior and thermo-mechanical instability: stress drops and strain bursts correlate with heat-induced phase transitions and nano-ABs/SN-ABs formations.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"266 ","pages":"Article 116783"},"PeriodicalIF":5.3000,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Deformation-induced amorphization and nanocrystallization in high-entropy alloys\",\"authors\":\"Bo Li, Nan Zi, Jiayin Zhao, Kaisheng Ming\",\"doi\":\"10.1016/j.scriptamat.2025.116783\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>High-entropy alloys (HEAs) with exceptional cryogenic strength and toughness are pivotal for extreme engineering applications, yet their deformation mechanisms at ultra-low temperatures remain incompletely understood. Here, we report two types of deformation-induced amorphization and nanocrystallization within amorphous bands in a CrMnFeCoNi HEA under tensile loading at 4.2 K. Unlike dislocation-driven amorphization that forms nanoscale amorphous bands (nano-ABs, >5 nm thick), supra-nanometer amorphous bands (SN-ABs, <5 nm thick) emerge via lattice distortion under extreme localized shear localization rather than dislocation accumulation. Concurrently, localized heating from plastic deformation triggers nanocrystallization within nano-ABs, generating randomly oriented nanograins. The amorphization and nanocrystallization are expected to provide an extra toughening mechanism for HEAs by dissipating strain energy and impeding shear localization. Crucially, we establish a microstructural link between low-temperature serrated flow behavior and thermo-mechanical instability: stress drops and strain bursts correlate with heat-induced phase transitions and nano-ABs/SN-ABs formations.</div></div>\",\"PeriodicalId\":423,\"journal\":{\"name\":\"Scripta Materialia\",\"volume\":\"266 \",\"pages\":\"Article 116783\"},\"PeriodicalIF\":5.3000,\"publicationDate\":\"2025-05-24\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Scripta Materialia\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1359646225002465\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Scripta Materialia","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1359646225002465","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Deformation-induced amorphization and nanocrystallization in high-entropy alloys
High-entropy alloys (HEAs) with exceptional cryogenic strength and toughness are pivotal for extreme engineering applications, yet their deformation mechanisms at ultra-low temperatures remain incompletely understood. Here, we report two types of deformation-induced amorphization and nanocrystallization within amorphous bands in a CrMnFeCoNi HEA under tensile loading at 4.2 K. Unlike dislocation-driven amorphization that forms nanoscale amorphous bands (nano-ABs, >5 nm thick), supra-nanometer amorphous bands (SN-ABs, <5 nm thick) emerge via lattice distortion under extreme localized shear localization rather than dislocation accumulation. Concurrently, localized heating from plastic deformation triggers nanocrystallization within nano-ABs, generating randomly oriented nanograins. The amorphization and nanocrystallization are expected to provide an extra toughening mechanism for HEAs by dissipating strain energy and impeding shear localization. Crucially, we establish a microstructural link between low-temperature serrated flow behavior and thermo-mechanical instability: stress drops and strain bursts correlate with heat-induced phase transitions and nano-ABs/SN-ABs formations.
期刊介绍:
Scripta Materialia is a LETTERS journal of Acta Materialia, providing a forum for the rapid publication of short communications on the relationship between the structure and the properties of inorganic materials. The emphasis is on originality rather than incremental research. Short reports on the development of materials with novel or substantially improved properties are also welcomed. Emphasis is on either the functional or mechanical behavior of metals, ceramics and semiconductors at all length scales.