TC4钛合金支座锻件低倍组织不均匀的研究

Study on Uneven Macrostructure of TC4 Titanium Alloy Bearing Forgings

钛合金在锻造过程中形成的不均匀低倍组织,在航空发动机零件中被视为不合格。本文采用有限元模拟分析了某支座TC4锻件原工艺的成形过程,发现原制坯工艺采用棒材反向拉拔变形方式不合理,造成了锻件心部变形量大,锻件表面变形量小,表现出锻件低倍组织不均匀。通过优化锻件制坯工艺,采用多火次拔长变形工艺后,显著地改善了锻件低倍组织均匀性。显微组织中初生α相含量较原工艺的提高10%。力学性能测试结果表明,工艺优化后的室温拉伸性能分布较均匀,超声检测满足相关技术标准的要求。

The uneven macrostructure formed in the forging process of titanium alloy is regarded as unqualified in aero engine parts.Using finite element simulation to analyze the forming process of the original process of a TC4 bearing forging.It is found that the original blanking process adopts the bar reverse drawing deformation method to be unreasonable,resulting in large deformation of the core of the forging and small surface deformation of the forging.The low-magnification structure of the forging is uneven.By optimizing the blank making process of forgings and adopting the multi-fire swaging deformation process,the uniformity of the low-magnification structure of the forgings is significantly improved.The content of primaryα-phase in the microstructure is increased by 10%compared with that of the original process.The mechanical performance test results show that the room temperature tensile performance distribution after the process optimization is relatively uniform,and the ultrasonic detection meets the requirements of the relevant technical standards.