激光立体成形GH4169高温合金γ″相的高温粗化行为

Coarsening Behavior ofγ″Precipitates in GH4169 Superalloy Fabricated by Laser Solid Forming

采用激光立体成形技术制备GH4169高温合金块体,对其在720～780℃温度区间进行不同保温时间的双级时效处理,采用微观测试分析方法对高温短时时效处理后γ＇quot;相的形态、尺寸变化及粗化动力学行为进行研究.结果表明：激光立体成形GH4169合金在不同保温时间双级时效条件下,γ＇quot;相形态基本为圆盘形;和保温时间相比,时效温度对γ＇quot;相的影响更为显著;γ＆quot;相的粗化规律符合Lifshitz Slyozov Wagner（LSW）理论,计算获得γ＇quot;的粗化激活能Q=281.85kJ/mol,较锻造GH4169合金的γ＇quot;粗化激活能略高,表明激光立体成形GH4169合金的组织稳定性优于锻态.

The bulk of GH4169 superalloy was fabricated by laser solid forming （LSF）. ple was treated with two-step aging treatment at 720-780℃ for different holding times. ogy, size and coarsening kinetics of γ＇ precipitates of LSFed GH4169 superalloy were croscopic measurements. The results show that the γ＇ precipitates evolve gradually to The bulk sam- The morphol- studied by mi- be disc-shaped in morphology during two-step aging treatment with different holding time. Compared with the hold- ing time, the aging temperature has more significant effect on the γ＇ precipitates. Meanwhile, the coarsening behavior of the γ＇ precipitates obeys the Lifshitz-Slyozov-Wagner（LSW） theory. The dif- fusion activation energy Q in coarsening of γ＇ precipitates precipitated in the LSFed GH4169 superal- loy is 281.85kJ/mol. It is slightly higher than that of the forged GH4169 superalloy, which indicates that the structural stability of LSFed GH4169 superalloy is better than that of the forged one.