{"title":"Al-Li-Cu-Mg-Sc-Zr铸造合金的高温力学性能:沉淀演变的综合研究","authors":"Shen Zhang, Guohua Wu, Liang Zhang, Xuanxi Xu, Fangzhou Qi, Xin Tong, Youjie Guo","doi":"10.1016/j.msea.2025.148576","DOIUrl":null,"url":null,"abstract":"<div><div>Cast Al-Li alloys with high Li content demonstrate exceptional weight reduction and stiffness enhancement effects, showing significant potential for aerospace structural components. However, their application is often constrained by service temperature limitations. In this study, the mechanical behavior and microstructural evolution of a cast Al-Li-Cu-Mg-Sc-Zr alloy were systematically investigated over a temperature range from room temperature to 300 °C. The results indicate that the Al<sub>3</sub>(Sc, Zr, Li) particles exhibit superior thermal stability, and their significant strengthening effect is crucial in maintaining yield strength exceeding 300 MPa even at 200 °C. At 100 °C, no significant alterations in alloy properties were observed compared to room temperature performance. The θ′ phase demonstrates poor coarsening resistance and undergoes extensive coarsening at 200 °C. The internal stresses generated by rapid coarsening and stress concentration during tension leads to microcrack formation at intersecting θ′ phases, resulting in a sharp decrease in elongation. Additionally, dislocation bands form within some grains, featuring dynamically precipitated fine S′ phases, which dominate transgranular fracture. The T<sub>1</sub> phase does not exhibit significant coarsening until 300 °C, while the θ′ and S′ phases are nearly completely dissolved at this temperature, resulting in significant strength reduction and exhibiting ductile fracture characteristics. This study provides valuable insights for the compositional design of cast Al-Li alloys and the enhancement of their mechanical properties at elevated temperatures.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"941 ","pages":"Article 148576"},"PeriodicalIF":7.0000,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Unraveling the elevated-temperature mechanical properties of a cast Al-Li-Cu-Mg-Sc-Zr alloy: A comprehensive investigation of precipitation evolution\",\"authors\":\"Shen Zhang, Guohua Wu, Liang Zhang, Xuanxi Xu, Fangzhou Qi, Xin Tong, Youjie Guo\",\"doi\":\"10.1016/j.msea.2025.148576\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Cast Al-Li alloys with high Li content demonstrate exceptional weight reduction and stiffness enhancement effects, showing significant potential for aerospace structural components. However, their application is often constrained by service temperature limitations. In this study, the mechanical behavior and microstructural evolution of a cast Al-Li-Cu-Mg-Sc-Zr alloy were systematically investigated over a temperature range from room temperature to 300 °C. The results indicate that the Al<sub>3</sub>(Sc, Zr, Li) particles exhibit superior thermal stability, and their significant strengthening effect is crucial in maintaining yield strength exceeding 300 MPa even at 200 °C. At 100 °C, no significant alterations in alloy properties were observed compared to room temperature performance. The θ′ phase demonstrates poor coarsening resistance and undergoes extensive coarsening at 200 °C. The internal stresses generated by rapid coarsening and stress concentration during tension leads to microcrack formation at intersecting θ′ phases, resulting in a sharp decrease in elongation. Additionally, dislocation bands form within some grains, featuring dynamically precipitated fine S′ phases, which dominate transgranular fracture. The T<sub>1</sub> phase does not exhibit significant coarsening until 300 °C, while the θ′ and S′ phases are nearly completely dissolved at this temperature, resulting in significant strength reduction and exhibiting ductile fracture characteristics. This study provides valuable insights for the compositional design of cast Al-Li alloys and the enhancement of their mechanical properties at elevated temperatures.</div></div>\",\"PeriodicalId\":385,\"journal\":{\"name\":\"Materials Science and Engineering: A\",\"volume\":\"941 \",\"pages\":\"Article 148576\"},\"PeriodicalIF\":7.0000,\"publicationDate\":\"2025-06-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materials Science and Engineering: A\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0921509325008007\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Science and Engineering: A","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921509325008007","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Unraveling the elevated-temperature mechanical properties of a cast Al-Li-Cu-Mg-Sc-Zr alloy: A comprehensive investigation of precipitation evolution
Cast Al-Li alloys with high Li content demonstrate exceptional weight reduction and stiffness enhancement effects, showing significant potential for aerospace structural components. However, their application is often constrained by service temperature limitations. In this study, the mechanical behavior and microstructural evolution of a cast Al-Li-Cu-Mg-Sc-Zr alloy were systematically investigated over a temperature range from room temperature to 300 °C. The results indicate that the Al3(Sc, Zr, Li) particles exhibit superior thermal stability, and their significant strengthening effect is crucial in maintaining yield strength exceeding 300 MPa even at 200 °C. At 100 °C, no significant alterations in alloy properties were observed compared to room temperature performance. The θ′ phase demonstrates poor coarsening resistance and undergoes extensive coarsening at 200 °C. The internal stresses generated by rapid coarsening and stress concentration during tension leads to microcrack formation at intersecting θ′ phases, resulting in a sharp decrease in elongation. Additionally, dislocation bands form within some grains, featuring dynamically precipitated fine S′ phases, which dominate transgranular fracture. The T1 phase does not exhibit significant coarsening until 300 °C, while the θ′ and S′ phases are nearly completely dissolved at this temperature, resulting in significant strength reduction and exhibiting ductile fracture characteristics. This study provides valuable insights for the compositional design of cast Al-Li alloys and the enhancement of their mechanical properties at elevated temperatures.
期刊介绍:
Materials Science and Engineering A provides an international medium for the publication of theoretical and experimental studies related to the load-bearing capacity of materials as influenced by their basic properties, processing history, microstructure and operating environment. Appropriate submissions to Materials Science and Engineering A should include scientific and/or engineering factors which affect the microstructure - strength relationships of materials and report the changes to mechanical behavior.