钛/铁复合板平底球形薄壁件充液拉深工艺研究

Hydromechanical Deep Drawing Process for Flat Bottom Spherical Thin-walled Part with Titanium/iron Composite Sheet

目的选用充液拉深先进成形技术制备钛/铁复合板平底球形薄壁件,并研究其充液拉深变形行为,以解决传统拉深工艺制备平底球形薄壁件极易产生褶皱的问题。方法对钛/铁复合板平底球形薄壁件在不同液压力、压边间隙及凸模与板料间摩擦因数等工艺参数下的充液拉深过程进行数值模拟。对数值模拟结果进行分析,讨论工艺参数对零件成形性能的影响以及抑制起皱的机理。最后在不同拉深工艺下进行成形试验,制备钛/铁复合板平底球形薄壁件并与数值模拟结果进行对比。结果数值模拟和成形试验结果表明,传统拉深工艺制备的钛/铁复合板平底球形薄壁件出现了明显的褶皱,采用充液拉深工艺可以有效解决零件侧壁起皱的问题。增大液压力、减小压边间隙或增大凸模与板料间摩擦因数会导致零件减薄率的提高并降低零件侧壁起皱的风险。在压边间隙1.5 mm、液压力25 MPa的条件下,采用充液拉深工艺可以制备出侧壁无褶皱的平底球形薄壁件。结论通过充液拉深工艺可以有效解决钛/铁复合板平底球形薄壁件成形过程中起皱的问题。

The work aims to form flat-bottom spherical thin-walled parts of titanium/iron composite sheets with advanced forming technology of hydromechanical deep drawing,and study the deformation behaviors of hydromechanical deep drawing,to solve the problem that the flat-bottom spherical thin-walled parts formed by conventional deep drawing are prone to wrinkle.The process of hydromechanical deep drawing of flat-bottom spherical thin-walled parts of titanium/iron composite sheets under different hydraulic pressure,blank holder gap,and friction coefficient between punch and blank was simulated numerically.The results of numerical simulation were analyzed to discuss the effects of process parameters on the formability of parts and the mechanism of wrinkle suppression.Finally,the forming experiments were carried out under different drawing processes,and the flat bottom spherical thin-walled parts of titanium/iron composite sheets were prepared and compared with the numerical simulation results.The results of numerical simulation and forming experiments showed that the flat-bottom spherical thin-walled parts of titanium/iron composite sheets formed by conventional deep drawing had obvious wrinkles,and the use of hydromechanical deep drawing could effectively solve the problem of side-wall wrinkling.Increasing the liquid pressure,decreasing the blank holder gap or increasing the friction coefficient between punch and blank could improve the part thinning rate and reduce the risk of side-wall wrinkling.Under a condition with blank holder gap of 1.5 mm and hydraulic pressure of 25 MPa,the flat-bottom spherical thin-walled parts without wrinkles on the side-wall could be formed by hydromechanical deep drawing.The problem of wrinkling in the forming process of flat-bottom spherical thin-walled parts of titanium/iron composite sheets can be effectively solved by hydromechanical deep drawing.