2A16 铝合金锥形件多级充液热成形仿真及优化分析

目的解决2A16铝合金锥形件常温充液成形困难、表面质量差的问题。方法介绍了充液热成形工艺,并提出了3种锥形件成形方案,通过专用有限元软件Dynaform对所有方案进行了数值仿真;同时,对一步成形方案进行了试验。结果通过试验验证了有限元模型的正确性。由仿真分析可知,成形缺陷包括悬空区起皱和凹模圆角及底部破裂,一步成形方案不可取,两步成形方案均可以将减薄率控制在13%以下。起皱危险主要发生在零件法兰以下30~55 mm处。结论充液热成形与常温充液成形相比,可以显著提高材料的成形性;两步充液热成形方案可以获得2A16铝合金锥形件;预成形凸模的形状设计对零件的表面质量影响明显;最终确定用先热冲压筒形件,后充液热成形的工艺方案,来成形2A16铝合金锥形件。

Optimization and Simulation Investigation on Muti-step Sheet Warm Hydroforming of 2A16 Aluminum Alloy Conical Part

Objective To solve the problems of forming difficulty and poor surface quality for normal hydro-mechanical deep drawing of 2A16 aluminum alloy conical part. Methods Sheet warm hydroforming was introduced and three solutions to form the conical part were designed. Numerical simulations were executed to analyze all the solutions using the finite ele-ment software Dynaform. Meanwhile, the experiment of one-step warm hydroforming was carried out. Results The correct-ness of the finite element model was verified by the experiments. As known from the analysis of the simulation, the forming defects included wrinkling of noncontact region and fracture at the punch corner and die corner. The scheme of one-step forming was not desirable, while two-step forming schemes could control the thinning rate below 13% and the risk of wrin-kling mainly occurred in the noncontact region of 30 to 55 mm below the part flange. Conclusion Compared with normal hydro-mechanical deep drawing, warm hydroforming significantly increased the formability of materials. Two-step warm hydroforming could successfully obtain 2A16 aluminum alloy conical part. The designed shape of preforming punch evident-ly affected the surface quality of the final part. The final solution was determined as first hot stamping the cylindrical part＆amp;nbsp;and then forming the conical part by warm hydroforming.