黏性介质压力成形技术研究进展

Research advancements of viscous pressure forming technology

黏性介质压力成形技术采用半固态、可流动、具有一定粘度的高分子聚合物作为传力介质,近年来已被应用于解决航空、航天等领域中难变形复杂形状零件的成形制造问题。黏性介质作为一种应变速率敏感性材料,能够在成形过程中自适应于板材的变形状态,其独特的力学性能有利于提高零件的尺寸精度、优化壁厚分布、克服局部失稳。针对黏性介质提供的黏性附着力提高板材成形性的机理、黏性介质压力成形过程中非均匀压力场的梯度分布特征和板材与体积变形的有限元法和无网格法的耦合算法等方面对黏性介质压力成形技术的研究进展进行了综述。

Viscous pressure forming technology adopts a kind of semisolid,flowable and viscous high molecular polymer to serve as the pressure-carrying medium,it has been applied to solve the manufacture problems of complex components for difficult-to-form materials in the field of aviation and space industry.Viscous medium is a kind of rate-dependent material which can be self-adjusted to the deformation state of sheet metal in the forming process.The unique mechanical properties of viscous medium are favorable for improving dimensional accuracy of parts,optimizing wall-thickness distribution as well as surmounting localized instability.Review of recent advancements of the technology of viscous pressure forming(VPF)process,including three aspects:the mechanism for the promotion of sheet formability due to viscous adhesive stress provided by viscous medium,the characteristic of gradient distribution for non-uniform stress field in VPF process and a coupled algorithm of finite element method and meshless method which takes coupled deformation of sheet and bulk into consideration,was made.