(营口理工学院 机械与动力工程系，营口 115000)
摘 要: 对无Ru和2%Ru镍基单晶高温合金在高温条件下进行蠕变性能测试。采用三维原子探针技术分别对有/无Ru合金在蠕变前/后各元素于γ/γ′两相的浓度分布进行测定。结果表明：2%Ru合金表现出了更好的高温蠕变性能，在1100 ℃/137 MPa条件下，2%Ru合金的蠕变寿命是125 h，而无Ru合金的蠕变寿命仅为58 h。元素Ru可提高元素在γ、γ′两相溶解度，降低元素在γ/γ′两相浓度比，提高合金中γ′相的合金化程度。经1100 ℃、137 MPa高温蠕变后，无Ru合金中各元素于γ/γ′两相中的浓度分布发生明显改变，其中元素W的浓度比由1/2.875(摩尔分数比)变为1/8.81，同时，各元素于γ/γ′两相界面处的浓度梯度明显增大。这种浓度分布的变化导致g相中难溶元素的含量增大，并析出TCP相，TCP相可破坏γ′相连续筏型结构，大幅降低合金蠕变性能。2%Ru合金中各元素在γ/γ′两相中的浓度分布和相界面处的浓度梯度均无明显变化。这表明高温蠕变可对合金中各元素在γ/γ′两相中的浓度分布和相界面的浓度梯度产生影响，元素Ru可抑制这种影响的产生。
关键字: Ru；镍基单晶高温合金；元素浓度分布；高温蠕变
（Yingkou Institute of Technology, Department of Mechanical and Power Engineering, Yingkou 115000, China）
Abstract:By meaning of measuring the creep properties under high temperatures of Ru-free and 2%Ru nickel-based single crystal superalloy. The results show that 2%Ru alloy exhibit longer creep life at 1100 ℃ and 137 MPa, which is 125h, while that of Ru-free alloys is only 58h. And the effect mechanism of Ru improving the creep resistance of nickel-based single superalloy is studied by measuring the concentration distribution of elements in γ/γ′ phases of free/with Ru alloy before and after crept. The results show that Ru element can increase the solubility of other elements in γ/γ′ phases, decrease the concentration distribution ratio of other elements in γ/γ′ phases and enhance the alloying extent of elements in γ′ phase. After creep of Ru-free at 1100 ℃/137 MPa, the concentration distribution of elements changes obviously in γ/γ′ phase, and the concentration distribution ratio of W element changes from 1/2.875 to 1/8.81, at the same time, the concentration gradient of elements at the interface of γ/γ′ phase increases significantly. The change of concentration distribution leads to the increase of the content of insoluble elements of γ phase and the precipitation of TCP phase, which can destroy the continuous rafted structure of γ′ phase and greatly reduce the creep property of the alloy. However, the concentration distribution of element in γ/γ′ phase and the concentration gradient at the interface of γ/γ′ phase of 2%Ru alloy do not change significantly, which is shown that the high temperature creep can affect the concentration distribution of elements in γ/γ′ phase and the concentration gradient at the phase interface, but Ru element can restrain the effect.
Key words: Ru; nickel-based single crystal superalloy; element concentration distribution; high temperature creep
