摘要
随着新一代低油耗和高推重比航空发动机的发展,对新型涡轮盘合金提出了更高的要求。FGH4096是典型第二代高强和高损伤容限型涡轮盘合金,长期使用温度为700~750℃,采用粉末冶金（P/M）工艺制备。本文采用电渣重熔连续定向凝固（ESR-CDS）技术和多向锻造技术制备了低偏析的FGH96合金（命名为CDS＆W FGH96）锻坯,通过等温热压缩实验研究了锻态合金在温度范围为1060~1140℃,应变速率范围为0.001~0.100 s-1的热变形特点。结果表明,随着温度的增加,再结晶（DRX）分数先减小后增加;弥散细小的γ＇相颗粒阻碍动态再结晶形核,而尺寸较大的相颗粒在一定程度上可大大降低对动态再结晶的这种阻碍作用;动态再结晶晶粒尺寸随着变形温度的降低而降低。通过流变行为计算得到热变形激活能为1289 k J·mol-1,并提出了合金CDS＆W FGH96高温变形本构方程。借助于场发射扫描电镜（FESEM）和透射电镜（TEM）阐述了动态再结晶机制为应变诱导原始晶界形核和第二相位错塞积形核。
The development of new generation of aero-engines with reduced specific fuel consumption and high thrust-weight ratio re- quires higher quality of turbine disk alloys. Superalloy FGH96, a typical second disk alloy with high strength and tolerance damage, has always been prepared by powder metallurgy （PM） route, and its thermal capacity can reach 700 ~ 750 ℃ over a long period of use. The thermal deformation characteristics of FGH96 alloy prepared by the combination of electric-slag remelting continuously direc- tional solidification （ESR-CDS） and multiple forging （named as CDS＆W FGH96） were investigated by isothermal compression tests with the temperature range of 1060 - 1 t40 ℃ and the strain rates of 0. 001 -0. 100 s-1. The results showed that the fraction of dynam- ic recrystallization （DRX） first decreased and then increased with the increase of deformation temperature ; the dispersed second phase particles could effectively retard the initiation of DRX, but the large particles could weaken this inhibiting effect obviously. The size of new DRX grains deceased with the decrease of deformation temperature. The apparent activation energy of deformation was calculated to be 1289 kJ.mol-1, and the constitutive equation that described the flow stress as a function of the strain rate and deformation tempera- ture was proposed for high temperature deformation of CDS＆W FGH96 alloy. The nucleation mechanisms of dynamic recrystallization were elaborated to be strain inducing previous grain boundary and dislocation piling-up near the second phase by transmission electron microscopy （TEM） and field emission scanning electron microscopy （FESEM）.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2015年第3期201-206,共6页
Chinese Journal of Rare Metals
基金
国家国防科工局军品配套项目(JPPT-125-GH-047)资助
