FGH96合金热挤压棒材超塑性研究  

Study on Superplasticity of Extruded FGH96 Alloy

作　　者：王淑云[1] 张敏聪[1] 东赟鹏[1] 刘趁意[1] 陈由红[1] 孙兴[1] 

机构地区：[1]北京航空材料研究院,北京100095

出　　处：《材料工程》2012年第7期24-28,共5页Journal of Materials Engineering

摘　　要：对热挤压FGH96合金棒材超塑性进行了研究,结果表明:挤压FGH96合金在1050℃和1100℃的变形温度下具有良好的超塑性,在变形温度为1100℃初始应变速率为3.33×10-4s-1进行超塑拉伸时,伸长率可以达到405%,流变应力降低到32MPa。显微组织分析表明,FGH96合金经控制冷却速度的预热处理后,合金中γ′相尺寸及间距较大,能够促进合金在后续变形过程动态再结晶的发生,并阻碍晶粒快速长大。FGH96合金在挤压变形后发生了明显的动态再结晶,但由于再结晶进行的不充分,晶粒内部仍存在大量变形亚结构,这种亚稳态组织在超塑变形过程中通过进一步回复和再结晶,可以获得平均晶粒尺寸为10μm左右的等轴、均匀、稳定的细晶组织,使合金具有良好的超塑性。The superplasticity of extruded FGH96 alloy was studied. The results show that the extru- ded FGH96 alloy exhibits excellent superplasticity at temperatures of 1050℃ and 1100℃. Superplastic elongation rate reaches 405% and flow stress is decreased to 32MPa at temperature of 1100℃ with the initial strain rate of 3.33×10^-4s^-1. The metallographic analysis indicates that the relatively large size of γ′ phase and the large distance between different 7p phases in FGH96 alloy can promote dynamic re- crystallization, and the grain growth can be restrained in the subsequent deformation. Evident dynam- ic recrystallization in FGH96 alloy has been occurred during the extrusion deformation. But due to the insufficient dynamic recrystallization in extrusion deformation, a large quantity of substructures still exists in the interior of the grain. The unstable substructures would cause finer, stable and uniform grains, the mean size of which is about 10μm, through dynamic recovery and dynamic recrystallization in superplastic deformation, thus resulting in excellent superplasticity of FGH96 alloy.

关 键 词：FGH96合金 挤压 超塑性 

分 类 号：TG113.26[金属学及工艺—物理冶金]