Xu Chen, Qihan Li, Ye Liu, Lin Zhang, Shuang He, Oleg I. Gorbatov, Xuanhui Qu
{"title":"AlCoCrFeNiCu0.5高熵合金在800℃和900℃下的氧化行为","authors":"Xu Chen, Qihan Li, Ye Liu, Lin Zhang, Shuang He, Oleg I. Gorbatov, Xuanhui Qu","doi":"10.1007/s12540-024-01872-w","DOIUrl":null,"url":null,"abstract":"<div><p>The oxidation behavior of AlCoCrFeNiCu<sub>0.5</sub> high-entropy alloy (HEA) in air at both 800 °C and 900 °C has been analyzed and corresponding microstructural evolution after oxidation has also been studied. The experimental studies revealed that the as-cast AlCoCrFeNiCu<sub>0.5</sub> alloy is mainly composed of BCC and FCC phases, moreover, there is a spinodal structure with the constituent phases being NiAl-B2 and FeCr-BCC. After annealing at 900 °C for 6 h, the spinodal structure disappeared, but there was σ phase at grain boundary. Oxidation caused significant changes in the matrix of the alloy. The primary phases of the oxidized matrix are the NiAl-B2 phase and FeCoCr-FCC1 phase. A substantial amount of Al was consumed in matrix to form Al<sub>2</sub>O<sub>3</sub> on the surface, resulting in the formation of Al-depleted layer. The longer the oxidation time, the thicker the Al-depleted layer, and a concentrated distribution of Cu-rich FCC2 phase was observed in this region. The isothermal oxidation kinetics of the alloy at both 800 °C and 900 °C followed the parabolic law. The <i>k</i><sub>p</sub> values for oxidation at 800 °C and 900 °C were 7.367 × 10<sup>− 14</sup> (g<sup>2</sup>·cm<sup>− 4</sup>·s<sup>− 1</sup>) and 2.105 × 10<sup>− 13</sup> (g<sup>2</sup>·cm<sup>− 4</sup>·s<sup>− 1</sup>) respectively, indicating that the <i>k</i><sub>p</sub> value at 900 °C was 2.86 times that at 800 °C. A continuous Al<sub>2</sub>O<sub>3</sub> layer on the surface being the key to its superior oxidation resistance of the HEA at both temperatures.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 7","pages":"1982 - 1995"},"PeriodicalIF":4.0000,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Oxidation Behavior of the AlCoCrFeNiCu0.5 High-Entropy Alloy at 800 °C and 900 °C\",\"authors\":\"Xu Chen, Qihan Li, Ye Liu, Lin Zhang, Shuang He, Oleg I. Gorbatov, Xuanhui Qu\",\"doi\":\"10.1007/s12540-024-01872-w\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The oxidation behavior of AlCoCrFeNiCu<sub>0.5</sub> high-entropy alloy (HEA) in air at both 800 °C and 900 °C has been analyzed and corresponding microstructural evolution after oxidation has also been studied. The experimental studies revealed that the as-cast AlCoCrFeNiCu<sub>0.5</sub> alloy is mainly composed of BCC and FCC phases, moreover, there is a spinodal structure with the constituent phases being NiAl-B2 and FeCr-BCC. After annealing at 900 °C for 6 h, the spinodal structure disappeared, but there was σ phase at grain boundary. Oxidation caused significant changes in the matrix of the alloy. The primary phases of the oxidized matrix are the NiAl-B2 phase and FeCoCr-FCC1 phase. A substantial amount of Al was consumed in matrix to form Al<sub>2</sub>O<sub>3</sub> on the surface, resulting in the formation of Al-depleted layer. The longer the oxidation time, the thicker the Al-depleted layer, and a concentrated distribution of Cu-rich FCC2 phase was observed in this region. The isothermal oxidation kinetics of the alloy at both 800 °C and 900 °C followed the parabolic law. The <i>k</i><sub>p</sub> values for oxidation at 800 °C and 900 °C were 7.367 × 10<sup>− 14</sup> (g<sup>2</sup>·cm<sup>− 4</sup>·s<sup>− 1</sup>) and 2.105 × 10<sup>− 13</sup> (g<sup>2</sup>·cm<sup>− 4</sup>·s<sup>− 1</sup>) respectively, indicating that the <i>k</i><sub>p</sub> value at 900 °C was 2.86 times that at 800 °C. A continuous Al<sub>2</sub>O<sub>3</sub> layer on the surface being the key to its superior oxidation resistance of the HEA at both temperatures.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>\",\"PeriodicalId\":703,\"journal\":{\"name\":\"Metals and Materials International\",\"volume\":\"31 7\",\"pages\":\"1982 - 1995\"},\"PeriodicalIF\":4.0000,\"publicationDate\":\"2025-01-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Metals and Materials International\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s12540-024-01872-w\",\"RegionNum\":3,\"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":"Metals and Materials International","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s12540-024-01872-w","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Oxidation Behavior of the AlCoCrFeNiCu0.5 High-Entropy Alloy at 800 °C and 900 °C
The oxidation behavior of AlCoCrFeNiCu0.5 high-entropy alloy (HEA) in air at both 800 °C and 900 °C has been analyzed and corresponding microstructural evolution after oxidation has also been studied. The experimental studies revealed that the as-cast AlCoCrFeNiCu0.5 alloy is mainly composed of BCC and FCC phases, moreover, there is a spinodal structure with the constituent phases being NiAl-B2 and FeCr-BCC. After annealing at 900 °C for 6 h, the spinodal structure disappeared, but there was σ phase at grain boundary. Oxidation caused significant changes in the matrix of the alloy. The primary phases of the oxidized matrix are the NiAl-B2 phase and FeCoCr-FCC1 phase. A substantial amount of Al was consumed in matrix to form Al2O3 on the surface, resulting in the formation of Al-depleted layer. The longer the oxidation time, the thicker the Al-depleted layer, and a concentrated distribution of Cu-rich FCC2 phase was observed in this region. The isothermal oxidation kinetics of the alloy at both 800 °C and 900 °C followed the parabolic law. The kp values for oxidation at 800 °C and 900 °C were 7.367 × 10− 14 (g2·cm− 4·s− 1) and 2.105 × 10− 13 (g2·cm− 4·s− 1) respectively, indicating that the kp value at 900 °C was 2.86 times that at 800 °C. A continuous Al2O3 layer on the surface being the key to its superior oxidation resistance of the HEA at both temperatures.
期刊介绍:
Metals and Materials International publishes original papers and occasional critical reviews on all aspects of research and technology in materials engineering: physical metallurgy, materials science, and processing of metals and other materials. Emphasis is placed on those aspects of the science of materials that are concerned with the relationships among the processing, structure and properties (mechanical, chemical, electrical, electrochemical, magnetic and optical) of materials. Aspects of processing include the melting, casting, and fabrication with the thermodynamics, kinetics and modeling.