{"title":"L12 强化镍钴基高熵合金的动态应变时效及其在应变时效过程中的变形机理解析","authors":"","doi":"10.1016/j.ijplas.2024.104151","DOIUrl":null,"url":null,"abstract":"<div><div>Dynamic strain ageing (DSA) of L1<sub>2</sub>-strengthened Ni-Co base high-entropy alloy (HEA) was examined at temperatures varying from 20 to 600 °C with strain rates between 10<sup>–</sup><sup>2</sup> to 10<sup>–4</sup> s<sup>-1</sup>. In normal DSA regimes, elevating temperature or lowering strain rate advances the DSA behavior, resulting in the lowered critical strain and raised amplitude of serrations. Based on strain-rate jump tests, the negative strain-rate sensitivity induced by DSA was observed at the elevated temperature regime, and high apparent activation volumes ranging from 97<span><math><mspace></mspace></math></span>∼ 737<span><math><msup><mi>b</mi><mn>3</mn></msup></math></span> correspond to the strong obstacles effect from the precipitates and the additional pinning strengthening of solute atoms. Transmission electron microscopy evidence suggests that stacking faults prevailed at all testing temperatures, while the serration changes are the outcomes of their dynamic interactions with precipitates and condensed Cr, Co-rich solute cloud. Subsequently, in normal DSA regimes, activation energies required for the onset of type A, a mixture of type A and type A + C, and a mixture of type <em>A</em> + <em>B</em> and type C serrations are 30.6, 65.8, and 101.1 kJ/mol determined by strain ageing model at strain rates of 10<sup>–2</sup>, 10<sup>–3</sup>, and 10<sup>–4</sup> s<sup>-1</sup>, respectively. Lastly, a two-time parameter-based Cottrell-Bilby strain aging kinetic model that considers the solute-dislocation interaction in a pipe diffusion manner is applied to evaluate the DSA strengthening concerning strain, strain rate, and temperature.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":null,"pages":null},"PeriodicalIF":9.4000,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Dynamic strain ageing of L12-strengthened Ni-Co base high-entropy alloy and unraveling its deformation mechanisms in strain ageing process\",\"authors\":\"\",\"doi\":\"10.1016/j.ijplas.2024.104151\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Dynamic strain ageing (DSA) of L1<sub>2</sub>-strengthened Ni-Co base high-entropy alloy (HEA) was examined at temperatures varying from 20 to 600 °C with strain rates between 10<sup>–</sup><sup>2</sup> to 10<sup>–4</sup> s<sup>-1</sup>. In normal DSA regimes, elevating temperature or lowering strain rate advances the DSA behavior, resulting in the lowered critical strain and raised amplitude of serrations. Based on strain-rate jump tests, the negative strain-rate sensitivity induced by DSA was observed at the elevated temperature regime, and high apparent activation volumes ranging from 97<span><math><mspace></mspace></math></span>∼ 737<span><math><msup><mi>b</mi><mn>3</mn></msup></math></span> correspond to the strong obstacles effect from the precipitates and the additional pinning strengthening of solute atoms. Transmission electron microscopy evidence suggests that stacking faults prevailed at all testing temperatures, while the serration changes are the outcomes of their dynamic interactions with precipitates and condensed Cr, Co-rich solute cloud. Subsequently, in normal DSA regimes, activation energies required for the onset of type A, a mixture of type A and type A + C, and a mixture of type <em>A</em> + <em>B</em> and type C serrations are 30.6, 65.8, and 101.1 kJ/mol determined by strain ageing model at strain rates of 10<sup>–2</sup>, 10<sup>–3</sup>, and 10<sup>–4</sup> s<sup>-1</sup>, respectively. Lastly, a two-time parameter-based Cottrell-Bilby strain aging kinetic model that considers the solute-dislocation interaction in a pipe diffusion manner is applied to evaluate the DSA strengthening concerning strain, strain rate, and temperature.</div></div>\",\"PeriodicalId\":340,\"journal\":{\"name\":\"International Journal of Plasticity\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":9.4000,\"publicationDate\":\"2024-10-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Plasticity\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S074964192400278X\",\"RegionNum\":1,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, MECHANICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Plasticity","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S074964192400278X","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
摘要
在温度为 20 至 600 °C、应变速率为 10-2 至 10-4 s-1 的条件下,对 L12 强化镍钴基高熵合金(HEA)的动态应变时效(DSA)进行了研究。在正常的 DSA 状态下,升高温度或降低应变速率会推进 DSA 行为,导致临界应变降低和锯齿振幅增大。根据应变速率跃迁试验,在升高的温度条件下观察到了由 DSA 引起的负应变速率敏感性,97∼ 737b3b3 的高表观活化体积与沉淀物的强障碍效应和溶质原子的额外针刺强化相对应。透射电子显微镜证据表明,堆叠断层在所有测试温度下都普遍存在,而锯齿状变化则是它们与沉淀物和凝结的富含铬、钴的溶质云动态相互作用的结果。随后,在应变速率为 10-2、10-3 和 10-4 s-1 时,通过应变时效模型确定了在正常 DSA 状态下,A 型锯齿、A 型和 A + C 型混合锯齿以及 A + B 型和 C 型混合锯齿发生所需的活化能分别为 30.6、65.8 和 101.1 kJ/mol。最后,应用基于两次参数的 Cottrell-Bilby 应变老化动力学模型来评估 DSA 在应变、应变速率和温度方面的强化,该模型考虑了溶质-位错相互作用的管道扩散方式。
Dynamic strain ageing of L12-strengthened Ni-Co base high-entropy alloy and unraveling its deformation mechanisms in strain ageing process
Dynamic strain ageing (DSA) of L12-strengthened Ni-Co base high-entropy alloy (HEA) was examined at temperatures varying from 20 to 600 °C with strain rates between 10–2 to 10–4 s-1. In normal DSA regimes, elevating temperature or lowering strain rate advances the DSA behavior, resulting in the lowered critical strain and raised amplitude of serrations. Based on strain-rate jump tests, the negative strain-rate sensitivity induced by DSA was observed at the elevated temperature regime, and high apparent activation volumes ranging from 97∼ 737 correspond to the strong obstacles effect from the precipitates and the additional pinning strengthening of solute atoms. Transmission electron microscopy evidence suggests that stacking faults prevailed at all testing temperatures, while the serration changes are the outcomes of their dynamic interactions with precipitates and condensed Cr, Co-rich solute cloud. Subsequently, in normal DSA regimes, activation energies required for the onset of type A, a mixture of type A and type A + C, and a mixture of type A + B and type C serrations are 30.6, 65.8, and 101.1 kJ/mol determined by strain ageing model at strain rates of 10–2, 10–3, and 10–4 s-1, respectively. Lastly, a two-time parameter-based Cottrell-Bilby strain aging kinetic model that considers the solute-dislocation interaction in a pipe diffusion manner is applied to evaluate the DSA strengthening concerning strain, strain rate, and temperature.
期刊介绍:
International Journal of Plasticity aims to present original research encompassing all facets of plastic deformation, damage, and fracture behavior in both isotropic and anisotropic solids. This includes exploring the thermodynamics of plasticity and fracture, continuum theory, and macroscopic as well as microscopic phenomena.
Topics of interest span the plastic behavior of single crystals and polycrystalline metals, ceramics, rocks, soils, composites, nanocrystalline and microelectronics materials, shape memory alloys, ferroelectric ceramics, thin films, and polymers. Additionally, the journal covers plasticity aspects of failure and fracture mechanics. Contributions involving significant experimental, numerical, or theoretical advancements that enhance the understanding of the plastic behavior of solids are particularly valued. Papers addressing the modeling of finite nonlinear elastic deformation, bearing similarities to the modeling of plastic deformation, are also welcomed.