电场处理对GH4199合金组织与变形行为的影响

Effects of electric field treatment on microstructure and deformation behavior of GH4199 superalloy

将电场处理技术应用于GH4199合金,研究电场对该合金组织和变形行为的影响。结果表明:电场处理使GH4199合金塑性提高,而合金强度无明显变化;在电场强度为2 kV/cm,温度为820℃条件下,GH4199合金经5 h电场处理塑性提高26.6%;合金经电场处理后产生退火孪晶,随处理时间的延长孪晶数量增加;孪晶的出现可以改变变形过程中显微裂纹的扩展方向,增加合金塑性变形功,推迟断裂时间,从而提高合金断裂延伸率;此外,电场处理提高了合金变形均匀性,亦能改善合金塑性。

The effects of electric field treatment on the microstructure and deformation behavior of GH4199 superalloy were studied. The results show that the electric field treatment increases the ductility of GH4199 alloy but no evident influence on the strength. The fracture elongation of GH4199 alloy reaches a peak value after electric field treatment at 820 ℃ for 5 h with a electric field intensity of 2 kV/cm. The annealing twins occur in GH4199 alloy with electric field treatment and the number of twins increases with the increasing holding time. It is found that the direction of microcrack propagation can be changed by the presence of the annealing twins during the tensile deformation, and it causes the increasing plastic deformation work and delays the fracture, these are considered as the reason of the increasing ductility of GH4199 alloy. On the other hand, since the plastic deformation uniformity can be improved by the electric field treatment, it also increases the fracture elongation of GH4199 alloy.