航空发动机薄壁W形封严环动模外压成形

External pressure forming of thin walled W-shaped sealing rings in aircraft engines using movable dies

液压成形是复杂薄壁零件制造的一种有效方法。针对某航空发动机的薄壁高温合金W形封严环构件,提出动模外压成形方法,并建立了有限元模型。基于数值模拟和工艺实验,分析了不同成形阶段的变形规律和压缩失稳的控制机理,在此基础上研究了毛坯成形区高度和型腔液压加载路径等关键工艺参数对零件成形结果的影响,探讨了成形过程中环向失稳起皱、型面不对称、材料堆叠等失效形式,提出了优化的参数。结果表明,提出的工艺方法可实现W形封严环的整体精确成形,采用优化的毛坯成形区高度和液压加载路径可获得成形精度较高、表面平滑无褶皱的试件。

Hydroforming is an effective method for manufacturing complex and thin walled parts. In order to develop a forming process of complicated thin walled superalloy W-shaped sealing rings, a technology scheme is proposed consisting of external pressure forming using movable dies and its finite element model is built. The deformation rule and destabilization mechanism are discussed at different forming stages. Moreover, the effects of key process parameters, including the heights of blank forming area and loading paths of cavity pressure on the quality of the parts, are explored with the assistance of numerical simulations and verification experiments. Furthermore, the failure modes during the forming process, including wrinkling in the circumferential direction, configurational asymmetry and accumulation folding are discussed, while the technological parameters are optimized. The results indicate that the proposed technological method is feasible for the accurate integral forming of W-shaped sealing rings; moreover, the parts with smooth surfaces and high quality can be successfully formed using optimal parameters.