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研究了长期时效对GH4169合金的显微组织和动态拉伸性能及变形行为的影响规律及机制.结果表明,应变速率为10~1—10~2 s~(-1)时,合金强度受时效时间影响显著,断裂延伸率随时效时间的延长呈降低趋势,在时效500 h后基本保持不变;高应变速率(10~3 s~(-1))条件下,长期时效对合金强度无明显影响,而断裂延伸率受时效时间的影响显著,长期时效造成的合金塑性劣化现象提前发生.高应变速率变形过程中,位错运动受阻来不及释放,在时效0—1000 h范围内,合金未出现强化相峰值尺寸效应,强度受时效时间的影响并不明显.长期时效后GH4169合金晶界δ相附近无析出带的产生,导致动态载荷下晶界塑性变形的协调能力降低,应变速率为10~3 s~(-1)时,合金塑性在短时间时效后迅速下降.
The effects of long-term aging on the microstructure, dynamic tensile properties and deformation behavior of GH4169 alloy were studied.The results show that the strength of the alloy is affected by the aging time at 10 ~ 1-10 ~ 2 s ~ (-1) The elongation at break was decreased with the aging time, and remained unchanged after 500 h aging. However, the long-term aging had no obvious effect on the strength of the alloy under high strain rate (10 ~ 3 s ~ (-1)) , While the elongation at break was significantly affected by the aging time, and the plastic ductility degradation caused by long-term aging occurred earlier.During the high strain rate deformation, the dislocation movement was delayed and could not be released. In the range of 0-1000 h, the alloy did not appear The effect of aging time on the strength of the strengthened phase is not obvious.The generation of no precipitation zone near the grain boundary δ phase of GH4169 alloy after long-term aging reduces the coordination ability of the plastic deformation under the dynamic load, and the strain rate is 10 ~ 3 s ~ (-1), the ductility of the alloy decreased rapidly after a short period of aging.