Ni_(3)Al基高温合金的成分设计及室温性能

Composition design and room temperature properties of Ni_(3)Al-based superalloys

为改善Ni_(3)Al基高温合金的室温性能,基于“团簇加连接原子模型”对Ni_(3)Al基合金进行了成分设计,考察了合金的显微组织、力学性能和耐蚀性。结果表明,退火前后合金均由β相、α相和基体γ′相组成。1050℃×24 h退火后Ni5Co5Cr2Al2.5Ti1.5合金中β相和α相在基体中分布均匀,不仅使其呈现出更优的力学性能(最大压缩率为29.35%,屈服强度为1796 MPa,硬度为546.35 HV),还诱导合金发生电偶腐蚀,增强了合金的钝化效果,使合金呈现出更好的耐蚀性(阻抗为7.74×10^(4)Ω,自腐蚀电位为-0.055 V(vs SCE),自腐蚀电流密度为5.93×10^(-7)A/cm^(2))。本文所设计合金的室温力学性能和耐蚀性与Ni_(3)Al相比均有显著改善,为高温合金的成分设计提供了新的研究思路。

Chemical composition of Nii_(3)Al-based alloy was designed based on the “Cluster-plus-glue-atom model” to improve its room temperature properties, the microstructure, mechanical properties and corrosion resistance of the alloys were investigated. The results show that the alloys before and after annealing are composed of β phase, α phase and matrix phase γ′. After annealing at 1050 ℃ for 24 h, β phase and α phase are evenly distributed in the matrix of Ni_(5)Co_(5)Cr_(2)Al_(2.5)Ti_(1.5) alloy, which improves not only the mechanical properties(maximum compression rate of 29.35%, yield strength of 1796 MPa, hardness of 546.35 HV), but also induces galvanic corrosion, enhances the passivation effect and improves the corrosion resistance(impedance of 7.74×10^(4) Ω, corrosion potential of-0.055 V(vs SCE), corrosion current density of 5.93×10^(-7) A/cm^(2)) of the alloys. The alloys designed in this paper show significant improvements in mechanical properties and corrosion resistance compared to Nii_(3)Al. This work provides a new avenue for research in the composition design of high-temperature alloys.