{"title":"通过自然时效加速 6082 Al-Mg-Si 合金的沉淀硬化","authors":"","doi":"10.1016/j.actamat.2024.120396","DOIUrl":null,"url":null,"abstract":"<div><p>It is well known that long time natural aging (NA) after quenching from solution treatment will significantly reduce the precipitation hardening kinetics and peak hardness of most 6xxx aluminum alloys during later artificial aging (AA). Here we demonstrate an effective strategy to accelerate precipitation hardening, taking advantage of NA. It is found that by a short time pre-aging (PA) at AA temperature, NA for up to 1 year can reduce the time to peak strength in a 6082 alloy during later AA. A simultaneous increase in yield strength and uniform elongation at peak-aged condition can be achieved as a result of finer and denser age-hardening precipitates than those formed by direct AA treatment. Quantitative characterization of the precipitate microstructure by annular dark field scanning transmission electron microscopy (ADF-STEM) and atom probe tomography (APT) reveals that PA generates a small fraction of fine β″ needle precipitates composed of 6–9 β″-eyes and a substantially high density of GP-zones composed of 3–5 β″-eyes, which are stable at room temperature and can grow easily into β″ upon AA. During NA after PA, more GP-zones with at least 2 β″-eyes form while the larger GP-zones inherited from PA grow further, both of which can act as the precursors of β″ precipitates during later AA.</p></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":null,"pages":null},"PeriodicalIF":8.3000,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1359645424007468/pdfft?md5=9638743b1137775dfa9d334f17609acb&pid=1-s2.0-S1359645424007468-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Accelerating precipitation hardening by natural aging in a 6082 Al-Mg-Si alloy\",\"authors\":\"\",\"doi\":\"10.1016/j.actamat.2024.120396\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>It is well known that long time natural aging (NA) after quenching from solution treatment will significantly reduce the precipitation hardening kinetics and peak hardness of most 6xxx aluminum alloys during later artificial aging (AA). Here we demonstrate an effective strategy to accelerate precipitation hardening, taking advantage of NA. It is found that by a short time pre-aging (PA) at AA temperature, NA for up to 1 year can reduce the time to peak strength in a 6082 alloy during later AA. A simultaneous increase in yield strength and uniform elongation at peak-aged condition can be achieved as a result of finer and denser age-hardening precipitates than those formed by direct AA treatment. Quantitative characterization of the precipitate microstructure by annular dark field scanning transmission electron microscopy (ADF-STEM) and atom probe tomography (APT) reveals that PA generates a small fraction of fine β″ needle precipitates composed of 6–9 β″-eyes and a substantially high density of GP-zones composed of 3–5 β″-eyes, which are stable at room temperature and can grow easily into β″ upon AA. During NA after PA, more GP-zones with at least 2 β″-eyes form while the larger GP-zones inherited from PA grow further, both of which can act as the precursors of β″ precipitates during later AA.</p></div>\",\"PeriodicalId\":238,\"journal\":{\"name\":\"Acta Materialia\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":8.3000,\"publicationDate\":\"2024-09-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S1359645424007468/pdfft?md5=9638743b1137775dfa9d334f17609acb&pid=1-s2.0-S1359645424007468-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Acta Materialia\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1359645424007468\",\"RegionNum\":1,\"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":"Acta Materialia","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1359645424007468","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
众所周知,固溶处理淬火后的长时间自然时效(NA)会显著降低大多数 6xxx 铝合金在后期人工时效(AA)过程中的沉淀硬化动力学和峰值硬度。在此,我们展示了一种利用 NA 加速沉淀硬化的有效策略。研究发现,通过在 AA 温度下进行短时间预时效 (PA)、长达 1 年的 NA 可以缩短 6082 合金在后期 AA 期间达到峰值强度的时间。由于时效硬化析出物比直接 AA 处理形成的析出物更细更密,因此在峰值时效条件下可同时提高屈服强度和均匀伸长率。通过环形暗场扫描透射电子显微镜(ADF-STEM)和原子探针断层扫描(APT)对沉淀物微观结构进行定量表征后发现,PA 产生了一小部分由 6-9 β″ 眼组成的细小 β″ 针状沉淀物,以及密度相当高的由 3-5 β″ 眼组成的 GP 区。在 PA 后的 NA 过程中,形成了更多至少有 2 个 β″-眼的 GP 区,而从 PA 继承而来的较大 GP 区则进一步增长,这两种 GP 区都可以在以后的 AA 过程中充当 β″ 沉淀的前体。
Accelerating precipitation hardening by natural aging in a 6082 Al-Mg-Si alloy
It is well known that long time natural aging (NA) after quenching from solution treatment will significantly reduce the precipitation hardening kinetics and peak hardness of most 6xxx aluminum alloys during later artificial aging (AA). Here we demonstrate an effective strategy to accelerate precipitation hardening, taking advantage of NA. It is found that by a short time pre-aging (PA) at AA temperature, NA for up to 1 year can reduce the time to peak strength in a 6082 alloy during later AA. A simultaneous increase in yield strength and uniform elongation at peak-aged condition can be achieved as a result of finer and denser age-hardening precipitates than those formed by direct AA treatment. Quantitative characterization of the precipitate microstructure by annular dark field scanning transmission electron microscopy (ADF-STEM) and atom probe tomography (APT) reveals that PA generates a small fraction of fine β″ needle precipitates composed of 6–9 β″-eyes and a substantially high density of GP-zones composed of 3–5 β″-eyes, which are stable at room temperature and can grow easily into β″ upon AA. During NA after PA, more GP-zones with at least 2 β″-eyes form while the larger GP-zones inherited from PA grow further, both of which can act as the precursors of β″ precipitates during later AA.
期刊介绍:
Acta Materialia serves as a platform for publishing full-length, original papers and commissioned overviews that contribute to a profound understanding of the correlation between the processing, structure, and properties of inorganic materials. The journal seeks papers with high impact potential or those that significantly propel the field forward. The scope includes the atomic and molecular arrangements, chemical and electronic structures, and microstructure of materials, focusing on their mechanical or functional behavior across all length scales, including nanostructures.