TC17钛合金盘锻件的工艺优化及组织性能分析

Analysis of Microstructure-Properties and Process Optimization of Disk Forging of TC17 Alloy

为了提高发动机转动盘件的服役性能,增加性能富裕度,对某发动机用TC17钛合金盘锻件原始固有方案的成形过程、微观组织、力学性能进行分析,发现原始方案的预制坯设计不合理,导致盘锻件的等效应变和组织分布不均匀,并使得盘锻件的塑性和低周疲劳性能偏低。针对这一问题,采用有限元模拟进行预制坯结构优化,进一步提升盘锻件的变形均匀性和组织性能水平。经优化后,锻件变形的不均匀性得到明显改善,而且锻件各部位的组织分布均匀、形貌特征合理,原始β晶粒呈拉长状,没有或者有少量β再结晶晶粒、晶界弯折、晶内为网篮结构。力学性能测试结果表明,优化方案生产的盘锻件的塑性和低周疲劳性能优于原始方案,而且优化后盘锻件各部位的力学性能分散度较小、稳定性较好。

In order to improve the service performance and increase the performance richness of the engine rotating disc,the forming process,microstructure and mechanical properties of TC17 titanium alloy disc forging of the original process for an engine were analyzed.It was found that the preforming design of the original process was unreasonable,which led to the uneven distribution of the equivalent strain and microstructure of the disc forging.The ductility and low cycle fatigue properties of disc forgings were low.To solve this problem,finite element simulation was used to optimize the preforming structure,and the deformation uniformity and microstructure performance of disk forgings were further improved.After optimization,the uneven deformation of forgings is obviously improved,and the microstructure distribution of each part of the forgings is uniform and the morphology characteristics are better.The morphology characteristics are the elongatedβgrains,and there is no or fewβrecrystallized grains,grain boundary bending,basket-waved structure inside grain.The results show that the ductility and low cycle fatigue properties of the disk forging of the optimized process are better than those of the original process,and the mechanical properties of each part of the optimized disc forgings have less dispersion and better stability.