{"title":"通过原子模拟研究Ti/Al对CoNiFeAlTi多主元素合金中L1₂纳米析出和变形行为的影响","authors":"Amin Esfandiarpour, Anshul D.S. Parmar, Silvia Bonfanti, Pawel Sobkowicz, Byeong-Joo Lee, Mikko Alava","doi":"10.1016/j.jallcom.2025.181580","DOIUrl":null,"url":null,"abstract":"Recent experimental studies on CoNi-based multi-principal element alloys (MPEAs) have demonstrated high strength and ductility, attributed to the formation of stable L1<sub>2</sub> nanoscale precipitates. However, the fundamental mechanisms behind such impressive properties in these complex alloys are not well understood. In this work, we investigate the effects of Ti and Al concentrations on the formation of L1<sub>2</sub> precipitates in (CoNiFe)<sub>84</sub>(Al<sub>8</sub>Ti<sub>8</sub>), (CoNiFe)<sub>86</sub>(Al<sub>7</sub>Ti<sub>7</sub>), (CoNiFe)<sub>88</sub>(Al<sub>6</sub>Ti<sub>6</sub>), and (CoNiFe)<sub>94</sub>(Al<sub>4</sub>Ti<sub>2</sub>) MPEAs using hybrid molecular dynamics/Monte Carlo (MD/MC) simulations and a developed MEAM interatomic potential for the CoNiFeTiAl system. Additionally, we study the effect of L1<sub>2</sub> precipitation on the mechanical properties and stacking fault energy of these MPEAs using MD. Our hybrid MD/MC simulations show that (CoNiFe)<sub>86</sub>(Al<sub>7</sub>Ti<sub>7</sub>) alloy exhibits the highest amount of L1<sub>2</sub> nanoprecipitates. We find that L1<sub>2</sub> precipitation increases the stacking fault energy, with higher Al and Ti contents leading to greater increases. Tensile simulations reveal that L1<sub>2</sub> precipitates enhance yield strength, with alloys exhibiting higher precipitation showing increased flow stress. We also investigate dislocation-nanoprecipitate interactions with different precipitate sizes in (CoNiFe)<sub>86</sub>(Al<sub>7</sub>Ti<sub>7</sub>) alloy. Larger nanoprecipitate sizes result in stronger dislocation pinning. Dislocation-precipitate interactions indicate that dislocations predominantly shear through 4–8 nm precipitates instead of looping around them (Orowan mechanism), which enhances strength while maintaining good ductility. Although the lattice mismatch between the L1<sub>2</sub> nanoprecipitate and the matrix is low (0.139 %), the significant difference in stacking fault energy between the L1<sub>2</sub> nanoprecipitate and the matrix results in stronger dislocation pinning. This fundamental understanding can guide the compositional design of MPEAs with tailored properties by controlling nanoscale precipitation.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"591 1","pages":"181580"},"PeriodicalIF":6.3000,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Exploring the impact of Ti/Al on L1₂ nanoprecipitation and deformation behavior in CoNiFeAlTi multi-principal element alloys through atomistic simulations\",\"authors\":\"Amin Esfandiarpour, Anshul D.S. Parmar, Silvia Bonfanti, Pawel Sobkowicz, Byeong-Joo Lee, Mikko Alava\",\"doi\":\"10.1016/j.jallcom.2025.181580\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Recent experimental studies on CoNi-based multi-principal element alloys (MPEAs) have demonstrated high strength and ductility, attributed to the formation of stable L1<sub>2</sub> nanoscale precipitates. However, the fundamental mechanisms behind such impressive properties in these complex alloys are not well understood. In this work, we investigate the effects of Ti and Al concentrations on the formation of L1<sub>2</sub> precipitates in (CoNiFe)<sub>84</sub>(Al<sub>8</sub>Ti<sub>8</sub>), (CoNiFe)<sub>86</sub>(Al<sub>7</sub>Ti<sub>7</sub>), (CoNiFe)<sub>88</sub>(Al<sub>6</sub>Ti<sub>6</sub>), and (CoNiFe)<sub>94</sub>(Al<sub>4</sub>Ti<sub>2</sub>) MPEAs using hybrid molecular dynamics/Monte Carlo (MD/MC) simulations and a developed MEAM interatomic potential for the CoNiFeTiAl system. Additionally, we study the effect of L1<sub>2</sub> precipitation on the mechanical properties and stacking fault energy of these MPEAs using MD. Our hybrid MD/MC simulations show that (CoNiFe)<sub>86</sub>(Al<sub>7</sub>Ti<sub>7</sub>) alloy exhibits the highest amount of L1<sub>2</sub> nanoprecipitates. We find that L1<sub>2</sub> precipitation increases the stacking fault energy, with higher Al and Ti contents leading to greater increases. Tensile simulations reveal that L1<sub>2</sub> precipitates enhance yield strength, with alloys exhibiting higher precipitation showing increased flow stress. We also investigate dislocation-nanoprecipitate interactions with different precipitate sizes in (CoNiFe)<sub>86</sub>(Al<sub>7</sub>Ti<sub>7</sub>) alloy. Larger nanoprecipitate sizes result in stronger dislocation pinning. Dislocation-precipitate interactions indicate that dislocations predominantly shear through 4–8 nm precipitates instead of looping around them (Orowan mechanism), which enhances strength while maintaining good ductility. Although the lattice mismatch between the L1<sub>2</sub> nanoprecipitate and the matrix is low (0.139 %), the significant difference in stacking fault energy between the L1<sub>2</sub> nanoprecipitate and the matrix results in stronger dislocation pinning. This fundamental understanding can guide the compositional design of MPEAs with tailored properties by controlling nanoscale precipitation.\",\"PeriodicalId\":344,\"journal\":{\"name\":\"Journal of Alloys and Compounds\",\"volume\":\"591 1\",\"pages\":\"181580\"},\"PeriodicalIF\":6.3000,\"publicationDate\":\"2025-06-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Alloys and Compounds\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://doi.org/10.1016/j.jallcom.2025.181580\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Alloys and Compounds","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1016/j.jallcom.2025.181580","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Exploring the impact of Ti/Al on L1₂ nanoprecipitation and deformation behavior in CoNiFeAlTi multi-principal element alloys through atomistic simulations
Recent experimental studies on CoNi-based multi-principal element alloys (MPEAs) have demonstrated high strength and ductility, attributed to the formation of stable L12 nanoscale precipitates. However, the fundamental mechanisms behind such impressive properties in these complex alloys are not well understood. In this work, we investigate the effects of Ti and Al concentrations on the formation of L12 precipitates in (CoNiFe)84(Al8Ti8), (CoNiFe)86(Al7Ti7), (CoNiFe)88(Al6Ti6), and (CoNiFe)94(Al4Ti2) MPEAs using hybrid molecular dynamics/Monte Carlo (MD/MC) simulations and a developed MEAM interatomic potential for the CoNiFeTiAl system. Additionally, we study the effect of L12 precipitation on the mechanical properties and stacking fault energy of these MPEAs using MD. Our hybrid MD/MC simulations show that (CoNiFe)86(Al7Ti7) alloy exhibits the highest amount of L12 nanoprecipitates. We find that L12 precipitation increases the stacking fault energy, with higher Al and Ti contents leading to greater increases. Tensile simulations reveal that L12 precipitates enhance yield strength, with alloys exhibiting higher precipitation showing increased flow stress. We also investigate dislocation-nanoprecipitate interactions with different precipitate sizes in (CoNiFe)86(Al7Ti7) alloy. Larger nanoprecipitate sizes result in stronger dislocation pinning. Dislocation-precipitate interactions indicate that dislocations predominantly shear through 4–8 nm precipitates instead of looping around them (Orowan mechanism), which enhances strength while maintaining good ductility. Although the lattice mismatch between the L12 nanoprecipitate and the matrix is low (0.139 %), the significant difference in stacking fault energy between the L12 nanoprecipitate and the matrix results in stronger dislocation pinning. This fundamental understanding can guide the compositional design of MPEAs with tailored properties by controlling nanoscale precipitation.
期刊介绍:
The Journal of Alloys and Compounds is intended to serve as an international medium for the publication of work on solid materials comprising compounds as well as alloys. Its great strength lies in the diversity of discipline which it encompasses, drawing together results from materials science, solid-state chemistry and physics.