金属薄壁管件外压缩径成形理论及实验研究

Theory and experimental research on outer pressure compression forming of thin metal tube part

起皱失稳问题是空心薄壁类零件在加工和应用领域的主要瓶颈。基于此,对金属薄壁管件缩径成形过程中的弹塑性失稳规律进行研究,提出预测缩径褶皱、提高成形件质量的方法及技术手段。基于L.H.Donnell线性屈曲理论,推导了管坯均布外压作用下的环向弹性及塑性起皱临界载荷表达式;探讨了成形条件及材料参数对管材抗起皱性能强弱的影响。利用固体颗粒介质缩径工艺实现了AA7075管材不同热处理条件下的缩径成形,工艺试验验证了管材缩径成形起皱失稳理论的相关结论。

The main factor restricting the production and application of diameter-reduced tube parts is the wrinkling instability problem. Therefore, the wrinkling instability laws in the process of tube outer pressure compression forming were researched, and the technology methods for winkle prediction and forming quality improvement were ascertained. Based on the theory of L. H. Donnell linear buckling, the circumferential elastic and plastic wrinkling critical load expression was deduced, the influences of the forming conditions on the wrinkled morphology and the shaping property were also discussed. The AA7075 diameter-reduced tube parts by using the blank under different heat treatment conditions were produced by solid granule medium forming（SGMF） technology, and the process tests proved the conclusions of theoretical analysis.