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利用金相显微镜、扫描电镜、透射电镜等手段分析了GH720Li合金在两相区热压缩后的变形空冷态及退火态组织特征,探讨了该合金的静态再结晶机制.发现GH720Li合金在1100℃热变形及其后的空冷过程中主要发生回复现象,仅有少数再结晶晶粒可通过亚晶合并和亚晶长大的方式形核并长大;大量γ’相的限制使再结晶过程只能局限于单个或几个晶粒内.经不同时间退火后,再结晶可开动应变诱导晶界迁移及多个晶粒交界处的位错塞积区形核等机制,但一次γ’相的存在抑制了合金的整体再结晶进程.在基体变形及再结晶过程进行的同时,合金中一次γ’相也能够参与变形过程并发生一定程度的回复及再结晶现象.
The deformation air-cooled and annealed microstructure of GH720Li alloy after hot-compression in two-phase region was analyzed by means of metallographic microscope, scanning electron microscope and transmission electron microscope. The static recrystallization mechanism of GH720Li alloy was also discussed. During the deformation and the subsequent air-cooling process, the recovery mainly occurs. Only a few recrystallized grains can nucleate and grow by means of subgrain consolidation and subgrain growth. The limitation of a large number of γ ’phases renders the recrystallization process only possible Confined to a single or a few grains.After annealing at different times, recrystallization can start the strain-induced grain boundary migration and dislocation at the junction of multiple grain boundaries nucleation and other mechanisms, but the presence of a γ ’phase Which inhibits the whole recrystallization process of the alloy.At the same time, the primary γ ’phase of the alloy can also participate in the deformation process with a certain degree of recovery and recrystallization.