热挤压态FGH95合金的动态再结晶机制研究

针对热挤压态FGH95合金进行变形温度为1050~1120 ℃、变形量为50%和70%、应变速率为10?4~1 s?1的热压缩试验，研究该合金动态再结晶（DRX）的组织演变和形核机制。结果表明:提高变形温度和降低应变速率可以促进小角度晶界向大角度晶界迁移，有利于动态再结晶晶粒的长大；变形温度和变形量对热挤压态FGH95合金的动态再结晶机理的影响不明显，而应变速率对动态再结晶机制影响较大；随着应变速率的增加，热挤压态FGH95合金由不连续动态再结晶机制逐渐转变为连续动态再结晶机制；热挤压态FGH95合金的动态再结晶以不连续动态再结晶形核机制为主，以连续动态再结晶形核机制为辅；在1050 ℃、1 s?1变形条件下，热挤压态FGH95合金发生连续动态再结晶形核。

Study on Dynamic Recrystallization Mechanism of Hot Extruded FGH95 Alloy

The hot compression tests were carried out on hot extruded FGH95 alloy with 1050~1120 ℃ temperatures, 50% and 70% deformation, and 10?4~1 s?1 strain rates. The microstructure evolution and nucleation mechanism of dynamic recrystallization (DRX) of this alloy were studied. The results show that increasing the deformation temperature and reducing the strain rate can promote the migration from low angle grain boundary to large angle grain boundary, which is beneficial to the growth of dynamically recrystallized grains. The influence of deformation temperatures and deformation on the dynamic recrystallization mechanism of hot extruded FGH95 alloy is not obvious, but the strain rate has a great influence on the dynamic recrystallization mechanism. With the increase of strain rate, the dynamic recrystallization mechanism of hot extruded FGH95 alloy gradually changes from discontinuous dynamic recrystallization mechanism to continuous dynamic recrystallization mechanism. The dynamic recrystallization mechanism of hot extruded FGH95 alloy is dominated by discontinuous dynamic recrystallization nucleation mechanism, supplemented by continuous dynamic recrystallization nucleation mechanism. Continuous dynamic recrystallization nucleation occurs at 1050 ℃, 1 s?1 deformation conditions.