ABSTRACT

After solutionizing and aging at 980°C for various durations, the compressive deformation behaviour and mechanisms of the directionally solidified nickel-based superalloy CM247LC are investigated at room temperature. Experimental results show that the yield strength decreases gradually from 991 ± 1.2–672 ± 7.5 MPa with increasing the γ′ precipitate size from 145 ± 2–604 ± 19 nm. Transmission electron microscope observations on the slightly deformed specimens reveal that, in contrast to previous researches, plastic deformation of all the specimens is controlled by strongly coupled dislocations cutting through γ′ precipitates. Based on these experimental results, the relationship between the yield strength and precipitate size is discussed.

摘要

研究了定向凝固镍基高温合金CM247LC在室温下在980°C下固溶和时效不同时间后的压缩变形行为和机理。实验结果表明，随着 γ' 析出物尺寸从 145 ± 2–604 ± 19 nm 增加，屈服强度从 991 ± 1.2–672 ± 7.5 MPa 逐渐降低。对轻微变形试样的透射电子显微镜观察表明，与以前的研究相比，所有试样的塑性变形都是由穿过 γ′ 析出物的强耦合位错控制的。基于这些实验结果，讨论了屈服强度和析出物尺寸之间的关系。