航空发动机铝合金筒体关键件锻造成形工艺

Forging process of key parts in aluminum alloy cylinder for aero-engine

以某航空发动机2A70铝合金筒体关键零部件为研究对象,此锻件在实际生产中经常出现毛边边角部开裂,且裂纹延伸至锻件本体,从而导致材料合格率不高。针对此问题,将压扁预制坯改进为挤压预制坯,再进行终锻,此外建立了现行的压扁＋终锻工艺以及改进的挤压＋终锻工艺的三维有限元模型,并对其成形过程进行分析。通过模拟结果显示,采用预挤压再进行锻压终成形的方式减少了角部的应力、应变集中以及出现裂纹和孔洞的问题,且变形分配更加合理。实验结果表明,采用挤压＋终锻的工艺不仅减少了现行的压扁＋终锻工艺成形过程中非加工表面折叠、毛边处开裂的问题,而且终锻件各部分晶粒大小分布均匀,并且将此锻件的材料利用率由51%提高到了79.5%以上。

Taking the key components of aluminum alloy 2 A70 cylinder for an aero-engine as the research object,the forgings crack at the edge and corner usually in the actual production,and the cracks extend to the center of forgings,which leads to a low qualified rate of products. In order to solve the above problem,the preformed blank of flattening was replaced by extrusion and then followed by a final forging. In addition,three-dimensional finite element models of the current process of flattening ＋ final forging and the promoted process of extrusion ＋ final forging were built,and their forming processes were analyzed. The simulation results show that the process of extrusion ＋final forging reduces stress-strain concentration at the corner area and eliminates crack and hole defects,and the material flow is more reasonable. The experimental verification shows that the process of extrusion ＋ final forging also reduces folding in the non-machined surface and crack at edge and corner occurred in the current process of flattening ＋ final forging,and the grain sizes are uniformity in all area of final forgings. Thus,the material utilization of the forgings increases from 51% to more than 79. 5%.