新型镍钴基高温合金拉伸性能和变形机制研究
Tensile Properties and Deformation Mechanism of Novel Ni-Co-Based Superalloy
王晨 1王兴茂 2于鸿垚 3王联波 4王瑞 3程体娟 3郭彩玉 3毕中南 3王占勇4
作者信息
- 1. 上海应用技术大学材料科学与工程学院,上海 201418;钢铁研究总院高温合金新材料北京市重点实验室,北京 100081
- 2. 钢铁研究总院高温合金新材料北京市重点实验室,北京 100081;兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州 730050
- 3. 钢铁研究总院高温合金新材料北京市重点实验室,北京 100081
- 4. 上海应用技术大学材料科学与工程学院,上海 201418
- 折叠
摘要
采用SEM、EBSD和TEM研究了室温(25 ℃)和中温(650、700和750 ℃)下新型镍钴基高温合金力学性能及其变形机制.结果表明:室温下,合金的屈服强度和延伸率分别是1176 MPa和22.5％,主要的变形机制为大量位错发生滑移,不全位错切割γ'相形成孤立层错.当温度达到650 ℃时,观察到微孪晶切割二次γ'相和γ基体,以连续层错切割二次γ'相和γ基体变形为主.在700～750 ℃时,以连续层错和微孪晶同时切割二次γ'相和γ基体为主,并且层错的长度和微孪晶的厚度随温度的升高而增加.650～750 ℃范围内,切割一次γ'相的机制从APB转变到孤立层错.讨论了中温条件下变形机制随温度的变化以及微孪晶、层错等的形成机制.其中给出了 a/6<112>不全位错剪切γ'相形成超点阵外禀层错(SESF)的一种原子互换扩散模型,解释微孪晶的形成过程,为进一步研制高性能水平的新型镍钴基高温合金提供参考.
Abstract
The mechanical properties and deformation mechanism of a novel Ni-Co-based superalloys at room temperature(25 ℃)and medium temperature(650,700 and 750 ℃)were studied using SEM,EBSD and TEM.The results show that the yield strength and elongation of the alloy at room temperature are 1176 MPa and 22.5％,respectively,and present decreasing trend with the temperature increasing.At room temperature,the main deformation mechanism is that a large number of dislocations slip,and the partial dislocations shear the γ'particles into isolated stacking faults.When the temperature reaches 650 ℃,it is observed that microtwins run through the secondary γ'particles and γ matrix,but it is mainly deformed by continuous stacking faults shearing secondary γ'particles and γ matrix.At 700-750 ℃,the secondary γ'particles and the γ matrix are sheared simultaneously by continuous stacking faults and microtwins,and the length of stacking faults and thickness of microtwins increase with the increase in temperature.In the 650-750 ℃ range,the mechanism for shearing a primary γ'particles changes from antiphase boundary(APB)to isolated stacking faults.This study discusses the variation of deformation mechanism with temperature and the formation mechanism of microtwins and stacking fault under medium temperature conditions.An atom interchange diffusion model for superlattice extrinsic stacking fault(SESF)formation of a/6<1 12>partial dislocation shearing γ'particles is presented,which explains the formation process of microtwins and provides a reference for the further development of novel Ni-Co-based superalloys with high performance level.
关键词
镍钴基高温合金/拉伸性能/变形机制/层错/微孪晶Key words
Ni-Co-based superalloy/tensile properties/deformation mechanism/stacking faults/microtwins引用本文复制引用
基金项目
国家自然科学基金(12205055)
国家重点研发计划(2021YFB3702500)
出版年
2024
NETL
NSTL
万方数据