(營口理工學(xué)院 機(jī)械與動力工程系，營口 115000)
摘 要: 對無Ru和2%Ru鎳基單晶高溫合金在高溫條件下進(jìn)行蠕變性能測試。采用三維原子探針技術(shù)分別對有/無Ru合金在蠕變前/后各元素于γ/γ′兩相的濃度分布進(jìn)行測定。結(jié)果表明：2%Ru合金表現(xiàn)出了更好的高溫蠕變性能，在1100 ℃/137 MPa條件下，2%Ru合金的蠕變壽命是125 h，而無Ru合金的蠕變壽命僅為58 h。元素Ru可提高元素在γ、γ′兩相溶解度，降低元素在γ/γ′兩相濃度比，提高合金中γ′相的合金化程度。經(jīng)1100 ℃、137 MPa高溫蠕變后，無Ru合金中各元素于γ/γ′兩相中的濃度分布發(fā)生明顯改變，其中元素W的濃度比由1/2.875(摩爾分?jǐn)?shù)比)變?yōu)?/8.81，同時，各元素于γ/γ′兩相界面處的濃度梯度明顯增大。這種濃度分布的變化導(dǎo)致g相中難溶元素的含量增大，并析出TCP相，TCP相可破壞γ′相連續(xù)筏型結(jié)構(gòu)，大幅降低合金蠕變性能。2%Ru合金中各元素在γ/γ′兩相中的濃度分布和相界面處的濃度梯度均無明顯變化。這表明高溫蠕變可對合金中各元素在γ/γ′兩相中的濃度分布和相界面的濃度梯度產(chǎn)生影響，元素Ru可抑制這種影響的產(chǎn)生。
關(guān)鍵字: Ru；鎳基單晶高溫合金；元素濃度分布；高溫蠕變
（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
