{"title":"L12-type Ni3Al-based high-entropy aluminides with superior strength-ductility: From design to criteria","authors":"Zheng Liu, Laiqi Zhang, Pengfei Zhao, Chao Wang","doi":"10.1016/j.intermet.2025.108979","DOIUrl":null,"url":null,"abstract":"<div><div>L1<sub>2</sub>-type Ni<sub>3</sub>Al-based high-entropy aluminides (HEAs) with superior strength-ductility synergy exhibit great potential as advanced structural materials. Nevertheless, effective design method and phase formation criteria applicable to L1<sub>2</sub>-type Ni<sub>3</sub>Al-based HEAs remain elusive. In this study, the design method of L1<sub>2</sub>-type Ni<sub>3</sub>Al-based HEAs was systematically discussed from site preference of atoms, selection of multi-principal elements to determination of stoichiometric ratio. A series of L1<sub>2</sub>-type Ni<sub>3</sub>Al-based HEAs with excellent mechanical properties were successfully developed using this design strategy, and corresponding phase formation criteria were proposed. The designed alloys exhibited a high volume fraction of ordered L1<sub>2</sub> phase (>75 %) and a small amount of disordered FCC phase. The as-cast HEAs-1 alloy showed excellent high yield strength (>600 MPa) and ultimate tensile strength (>1200 MPa) with large tensile elongation (>35 %). Moreover, a new thermodynamic parameter, enthalpy-entropy ratio <span><math><mrow><mi>η</mi></mrow></math></span>, was established based on the pseudo-binary sublattice model. The formation of L1<sub>2</sub>-type Ni<sub>3</sub>Al-based HEAs is conducive within the ranges of <span><math><mrow><mi>η</mi><mo>≥</mo><mn>1.1</mn></mrow></math></span>, <span><math><mrow><msubsup><mi>δ</mi><mi>r</mi><mo>∗</mo></msubsup><mo><</mo><mn>3</mn><mo>%</mo></mrow></math></span>, <span><math><mrow><mn>4.5</mn><mo>%</mo><mo><</mo><msubsup><mi>δ</mi><mi>r</mi><mrow><mi>A</mi><mo>−</mo><mi>B</mi></mrow></msubsup><mo><</mo><mn>6.5</mn><mo>%</mo></mrow></math></span>, <span><math><mrow><mo>Δ</mo><msup><mi>χ</mi><mo>∗</mo></msup><mo><</mo><mn>5.5</mn><mo>%</mo></mrow></math></span>, <span><math><mrow><mn>6</mn><mo>%</mo><mo><</mo><mo>Δ</mo><msup><mi>χ</mi><mrow><mi>A</mi><mo>−</mo><mi>B</mi></mrow></msup><mo><</mo><mn>9.5</mn><mo>%</mo></mrow></math></span>, <span><math><mrow><msubsup><mi>σ</mi><mrow><mi>V</mi><mi>E</mi><mi>C</mi></mrow><mo>∗</mo></msubsup><mo><</mo><mn>1.1</mn></mrow></math></span>, <span><math><mrow><mn>2</mn><mo><</mo><msubsup><mi>σ</mi><mrow><mi>V</mi><mi>E</mi><mi>C</mi></mrow><mrow><mi>A</mi><mo>−</mo><mi>B</mi></mrow></msubsup><mo><</mo><mn>3</mn></mrow></math></span>, and <span><math><mrow><mn>8</mn><mo><</mo><mi>V</mi><mi>E</mi><msub><mi>C</mi><mrow><mi>t</mi><mi>o</mi><mi>t</mi></mrow></msub><mo><</mo><mn>8.5</mn></mrow></math></span>. The correctness and validity of the phase formation criteria were verified through the designed experiments. The criteria are simple and reliable, and can provide method and guidance for designing and developing advanced structural materials with superior mechanical properties.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"187 ","pages":"Article 108979"},"PeriodicalIF":4.8000,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Intermetallics","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0966979525003449","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}
引用次数: 0
Abstract
L12-type Ni3Al-based high-entropy aluminides (HEAs) with superior strength-ductility synergy exhibit great potential as advanced structural materials. Nevertheless, effective design method and phase formation criteria applicable to L12-type Ni3Al-based HEAs remain elusive. In this study, the design method of L12-type Ni3Al-based HEAs was systematically discussed from site preference of atoms, selection of multi-principal elements to determination of stoichiometric ratio. A series of L12-type Ni3Al-based HEAs with excellent mechanical properties were successfully developed using this design strategy, and corresponding phase formation criteria were proposed. The designed alloys exhibited a high volume fraction of ordered L12 phase (>75 %) and a small amount of disordered FCC phase. The as-cast HEAs-1 alloy showed excellent high yield strength (>600 MPa) and ultimate tensile strength (>1200 MPa) with large tensile elongation (>35 %). Moreover, a new thermodynamic parameter, enthalpy-entropy ratio , was established based on the pseudo-binary sublattice model. The formation of L12-type Ni3Al-based HEAs is conducive within the ranges of , , , , , , , and . The correctness and validity of the phase formation criteria were verified through the designed experiments. The criteria are simple and reliable, and can provide method and guidance for designing and developing advanced structural materials with superior mechanical properties.
期刊介绍:
This journal is a platform for publishing innovative research and overviews for advancing our understanding of the structure, property, and functionality of complex metallic alloys, including intermetallics, metallic glasses, and high entropy alloys.
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