摘要
采用原子探针仪器LEAP 4000X Si,研究镍基高温合金Ni-Al-Cr-W-Re-Ru长期时效后的元素分布规律。结果表明,Ni、Cr和Re原子在无序γ(fcc)-基体相中富集,而Al和W原子更多分配到有序γ'(L1_2)-析出相。在γ/γ'相界面γ相一侧出现Ni原子局部富集,导致界面自由能降低。γ'相中,溶质元素原子浓度总和约25at%,实验局部Al-R(R=Re、Ru或W)RDF在第1最近邻距离处负相关,说明Re、Ru和W优先占据Ni3Al(L1_2)结构的Al位。和三元合金Ni-Al-Cr相比,添加W、Re和Ru后,合金的γ相得到固溶强化,γ'相体积分数提高,硬度增加。
Distribution of alloying elements of a Ni-based superalloy after long-time aging was studied by LEAP 4000X Si. Elements like Ni, Cr and Re preferentially partition to the ）, phase, while Al and W have a preference for 7＇ phase. A local accumulation of Ni is found on the matrix side at the γ/γ＇ interface, leading to a reduction of interfacial free energy. The sum solute elemental concentration is -25at% and the experimental partial RDFs of A1-R （R=Re, Ru or W） exhibit negative correlation at first-NN distances in precipitates, indicating that refractory elements substitute preferentially to the A1 sublattice sites. The solid-solution strengthening effect of refractory elements and the increase in precipitates volume fraction result in an increase in microhardness, compared to the base Ni-A1-Cr alloy.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2018年第1期261-266,共6页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51405316)
中央高校基本科研业务费资助(2014SCU11062)
关键词
镍基高温合金
原子探针层析技术
元素分布
强化
Ni-based superalloy
atom probe tomography
elements distribution
strengthening
