高温钛合金航空发动机叶盘锻造变形均匀性研究

Study on forging deformation uniformity of high-temperature titanium alloy aero-engine blade disc

为了提高某航空发动机叶盘锻件的组织均匀性和锻件的力学性能,提出将小变形区反向追踪到原始坯料所在区域,并减少该区域材料的预制坯设计方法。首先通过热压缩实验获得某高温钛合金的流变曲线,并使用该流变曲线构建了某发动机叶盘锻件的有限元模型。然后通过有限元仿真结果分析了锻件的小变形区和大变形区在原始坯料中的位置,随后通过减少小变形区材料的方法设计了坯料形状。经过3次坯料更新后,处于推荐等效应变范围内的坯料体积从40%提高到了90%,显著提升了锻件的变形均匀性。实验结果表明,优化后的坯料能够得到组织比较均匀的锻件,平均晶粒尺寸相比原始材料显著减小,满足性能要求。此外,晶相分析结果验证了太大或太小的变形量都会导致锻件的平均晶粒尺寸偏大。

To improve the microstructure uniformity and mechanical properties of an aero-engine blade disc forgings,the preform design method,which traces the small deformation area back to the original blank area and reduce the material in this area was proposed.Firstly,the rheological curves of a high-temperature titanium alloy was obtained through thermal compression experiments,and the finite element model of an engine blade disk forging was constructed using the rheological curves.Then,the locations of the small deformation area and large deformation area of the forgings in the original blank were analyzed through the finite element simulation results,and then the blank shape was designed by reducing the materials in the small deformation areas.After three times of blank updating,the blank volume within the recommended effective strain range increases from 40%to 90%,which significantly improves the deformation uni-formity of forgings.The experiments results show that the optimized blank can obtain the forgings with a relatively uniform microstruc-ture,and the average grain size is significantly reduced compared with the original material,which meets the performance require-ments.In addition,the crystal phase analysis results verify that too large or too small deformation amount can lead to large average grain size of forgings.