DZ68合金的持久性能研究

Study on rupture properties of DZ68 alloy

为满足海空环境下服役的航空发动机使用要求,中国科学院金属研究所研制出了一种新型镍基高温合金DZ68.测定了合金的持久性能,采用扫描电镜、透射电镜等仪器观察了DZ68合金的微观组织.研究发现,DZ68合金的持久性能水平与DZ125合金相当.温度低于760℃时,持久样品组织中的γ'没有形筏;随着温度升高,γ'之间形筏;相同温度条件下,随着应力增加γ'筏排化趋势增大.760℃时,持久样品中的位错从基体切入γ相是整个变形过程的控制步骤,此时合金从断裂机制上表现为解理断裂;随着温度升高,断裂方式由解理和准解理混合型断裂转变为微孔聚集型断裂.

To meet the requirements of marine gas turbine blade materials,a new-type directional solidification nickel-base superalloy named DZ68 was developed independently by Institute of Metal Research,Chinese Academy of Sciences.The rupture properties of the new alloy were tested in the paper,and the microstructure of the rupture samples were investigated by scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The rupture life of the alloy is the same as that of DZ125 alloy.When temperature is lower than 760 ℃,the shape of γ particles doesn＇t change obviously,and at 760 ℃,the deformation is dominated by dislocation shearing γ′,and the fracture mode exhibits cleavage feature.At the same temperature,the rafted structure evidently increase with the increasing of test stress,while with the increasing of temperature,the fracture mode changes from cleavage feature to microvoid gathered fracture mode.