{"title":"氧分压驱动下(Fe4Al3Cr)0.25TiO5晶须原位生长机理及刚玉型中熵氧化物增强力学性能","authors":"Wenxue Wang, Kang Wang, Chao Ma, Wei Yang, Junpeng Jiang, Rui Zhao, Daoyang Han, Hailong Wang, Rui Zhang","doi":"10.1002/advs.202508378","DOIUrl":null,"url":null,"abstract":"<p>Designing in situ whiskers to enhance the fracture toughness of ceramics presents challenges for structural applications. Herein, two corundum-type medium-entropy oxide ceramics (MEO-1 and MEO-2) are synthesized through solid-state reaction sintering under controlled oxygen partial pressures. MEO-1 is a single-phase corundum-type oxide (Al<sub>0.41</sub>Cr<sub>0.26</sub>Fe<sub>0.31</sub>Ti<sub>0.02</sub>)<sub>2</sub>O<sub>3</sub>, while MEO-2 incorporates (Fe<sub>4</sub>Al<sub>3</sub>Cr)<sub>0.25</sub>TiO<sub>5</sub> whiskers to reinforce (Al<sub>0.40</sub>Cr<sub>0.25</sub>Fe<sub>0.30</sub>Ti<sub>0.05</sub>)<sub>2</sub>O<sub>3</sub>. By regulating variable valence ions at different oxygen partial pressures, the whiskers achieved a maximum average length of 28.3 µm and a length-to-diameter ratio of 17.7 at 50.6 kPa, significantly enhancing the fracture toughness of the MEO-2, which possesses the optimal flexural strength, Vickers hardness, and fracture toughness of 321 ± 8 MPa, 22.4 ± 1.5 GPa, and 3.87 ± 0.12 MPa m<sup>1/2</sup>, respectively. Bravais–Friedel–Donnay–Harker law (BFDH) simulation elucidates that oxygen partial pressures can effectively regulate ionic diffusion behavior and whisker growth. First-principles calculations demonstrate that the whisker growth direction [0 4 0] aligns with the high shear modulus direction, contributing to the strengthening mechanism. This work provides new insights for designing high-performance medium/high-entropy ceramics, highlighting the critical role of oxygen partial pressure in regulating whisker growth and improving mechanical properties.</p>","PeriodicalId":117,"journal":{"name":"Advanced Science","volume":"12 35","pages":""},"PeriodicalIF":14.1000,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://advanced.onlinelibrary.wiley.com/doi/epdf/10.1002/advs.202508378","citationCount":"0","resultStr":"{\"title\":\"Mechanisms of In Situ Growth of (Fe4Al3Cr)0.25TiO5 Whisker Driven by Oxygen Partial Pressure and Reinforced Mechanical Properties in Corundum-Type Medium-Entropy Oxides\",\"authors\":\"Wenxue Wang, Kang Wang, Chao Ma, Wei Yang, Junpeng Jiang, Rui Zhao, Daoyang Han, Hailong Wang, Rui Zhang\",\"doi\":\"10.1002/advs.202508378\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Designing in situ whiskers to enhance the fracture toughness of ceramics presents challenges for structural applications. Herein, two corundum-type medium-entropy oxide ceramics (MEO-1 and MEO-2) are synthesized through solid-state reaction sintering under controlled oxygen partial pressures. MEO-1 is a single-phase corundum-type oxide (Al<sub>0.41</sub>Cr<sub>0.26</sub>Fe<sub>0.31</sub>Ti<sub>0.02</sub>)<sub>2</sub>O<sub>3</sub>, while MEO-2 incorporates (Fe<sub>4</sub>Al<sub>3</sub>Cr)<sub>0.25</sub>TiO<sub>5</sub> whiskers to reinforce (Al<sub>0.40</sub>Cr<sub>0.25</sub>Fe<sub>0.30</sub>Ti<sub>0.05</sub>)<sub>2</sub>O<sub>3</sub>. By regulating variable valence ions at different oxygen partial pressures, the whiskers achieved a maximum average length of 28.3 µm and a length-to-diameter ratio of 17.7 at 50.6 kPa, significantly enhancing the fracture toughness of the MEO-2, which possesses the optimal flexural strength, Vickers hardness, and fracture toughness of 321 ± 8 MPa, 22.4 ± 1.5 GPa, and 3.87 ± 0.12 MPa m<sup>1/2</sup>, respectively. Bravais–Friedel–Donnay–Harker law (BFDH) simulation elucidates that oxygen partial pressures can effectively regulate ionic diffusion behavior and whisker growth. First-principles calculations demonstrate that the whisker growth direction [0 4 0] aligns with the high shear modulus direction, contributing to the strengthening mechanism. This work provides new insights for designing high-performance medium/high-entropy ceramics, highlighting the critical role of oxygen partial pressure in regulating whisker growth and improving mechanical properties.</p>\",\"PeriodicalId\":117,\"journal\":{\"name\":\"Advanced Science\",\"volume\":\"12 35\",\"pages\":\"\"},\"PeriodicalIF\":14.1000,\"publicationDate\":\"2025-07-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://advanced.onlinelibrary.wiley.com/doi/epdf/10.1002/advs.202508378\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advanced Science\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://advanced.onlinelibrary.wiley.com/doi/10.1002/advs.202508378\",\"RegionNum\":1,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced Science","FirstCategoryId":"88","ListUrlMain":"https://advanced.onlinelibrary.wiley.com/doi/10.1002/advs.202508378","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Mechanisms of In Situ Growth of (Fe4Al3Cr)0.25TiO5 Whisker Driven by Oxygen Partial Pressure and Reinforced Mechanical Properties in Corundum-Type Medium-Entropy Oxides
Designing in situ whiskers to enhance the fracture toughness of ceramics presents challenges for structural applications. Herein, two corundum-type medium-entropy oxide ceramics (MEO-1 and MEO-2) are synthesized through solid-state reaction sintering under controlled oxygen partial pressures. MEO-1 is a single-phase corundum-type oxide (Al0.41Cr0.26Fe0.31Ti0.02)2O3, while MEO-2 incorporates (Fe4Al3Cr)0.25TiO5 whiskers to reinforce (Al0.40Cr0.25Fe0.30Ti0.05)2O3. By regulating variable valence ions at different oxygen partial pressures, the whiskers achieved a maximum average length of 28.3 µm and a length-to-diameter ratio of 17.7 at 50.6 kPa, significantly enhancing the fracture toughness of the MEO-2, which possesses the optimal flexural strength, Vickers hardness, and fracture toughness of 321 ± 8 MPa, 22.4 ± 1.5 GPa, and 3.87 ± 0.12 MPa m1/2, respectively. Bravais–Friedel–Donnay–Harker law (BFDH) simulation elucidates that oxygen partial pressures can effectively regulate ionic diffusion behavior and whisker growth. First-principles calculations demonstrate that the whisker growth direction [0 4 0] aligns with the high shear modulus direction, contributing to the strengthening mechanism. This work provides new insights for designing high-performance medium/high-entropy ceramics, highlighting the critical role of oxygen partial pressure in regulating whisker growth and improving mechanical properties.
期刊介绍:
Advanced Science is a prestigious open access journal that focuses on interdisciplinary research in materials science, physics, chemistry, medical and life sciences, and engineering. The journal aims to promote cutting-edge research by employing a rigorous and impartial review process. It is committed to presenting research articles with the highest quality production standards, ensuring maximum accessibility of top scientific findings. With its vibrant and innovative publication platform, Advanced Science seeks to revolutionize the dissemination and organization of scientific knowledge.