合金成分对含铼镍基单晶合金高温持久和断裂性能影响.doc

....页眉....页脚. 合金成分对含铼镍基单晶合金高温持久及断裂性能的影响来源: 开关柜无线测温究含铼镍基单晶合金主要合金化元素 W, Re, Ta, Al, RE 等含量变化对其高温( 980 ~ 1100 ℃)持久性能和持久断裂特征的影响,探索优化合金元素配比的基本原理,并分析其对持久断裂行为的影响。结果发现:适当提高 Re,W, Nb, Ta, Al 含量有利于高温持久性能改善, 这些元素间存在互相抵消或补偿的效用, 必须进行各元素含量匹配才能综合优化。适量添加稀土对改善合金持久蠕变的性能效果独特,从而证明利用其它合金元素部分代替铼的合理性。初步分析表明:以上效用归因于元素对合金相强化、相体积含量以及对持久蠕变动力学特别是γ′相熟化综合作用的结果。本文初步设计出含铼小于 % 低成本第二代单晶合金。关键词单晶高温合金成分持久蠕变断裂 Effects position on High Temperature Rupture and Fracture Feature of Re-containing Ni-based Single Crystal Superalloys Wei Pengyi Zhong Zhengang Gui Zhonglou Liu Rongmin Lao RilingLi Jiarong (Institute of Aeronautical Materials,Beijing) [ Abstract ]A new secondary generation Ni-based single crystal superalloy containing only 2wt%Re was developed. Effects of main alloying elements, W, Re, Ta, Al, RE ,on high temperatures(980 ~ 1100 ℃)rupture ....页眉....页脚. properties and fracture surface characteristics of Re-containing Ni-based single crystal superalloys were investigated to explore the principle for improving alloying and understand the fracture behavior in this series of alloy. It is found that: increasing the contents of Re,W, Nb, Ta, Al,RE, to certain extent will contribute to improvement of high temperature rupture properties, and then it is turned out to be reasonable to decrease the necessary Re contents by matching of contents of elements other than Re, especially minor addition of RE. Those results are due to individual and mutual effect on strengthening and volume fraction of alloy phases( γ′, γ) and coarsening dynamics of γ′ phase during creep process. Keywords single crystal superalloy content creep rupture fracture 含铼镍基单晶合金以其优越的高温持久和抗蠕变等性能, 已在先进航空发动机、地面燃气发电机等动力装置中得到广泛应用[ 1~3 ]。铼对单晶合金的合金化作用虽显著,但我国铼非常稀贵,因而深入研究铼合金化机理,利用低成本合金元素部分替代铼或优化工艺对研制我国的低成本第二代单晶合金十分必要. 本文通过研究 Re,Ta ,W, Al, RE 等元素含量对单晶合金高温持久性能及其断口特征的影响,探索单晶合金中降低铼含量的可能性和合金化新途径。 1 试验方法高纯度元素真空感应熔配如表 1 所示 17 种合金, 真空感应定向凝固在相同工艺条件下制备单晶试板( 15mm × 35mm × 150mm ), 采用与合金成分适应的热处理工艺,即 1310 ~ 1340 ℃× 4h,.+1100 ℃× 4h,.+870 ℃× 32h,. 然后