TC4钛合金薄壁带筋锥形环辗轧充填规律

钛合金薄壁带筋锥形环件是航空航天关键基础构件,型槽充填不满、截面轮廓难以精确成形,是该复杂异形环件精密辗轧成形面临的瓶颈问题。本文分析了影响型槽充填行为的关键影响因素,即决定塑性变形行为的每转进给量、以及决定每转进给量在环件内外表面分配比例的驱动辊半径和芯辊半径;以某TC4钛合金薄壁带外筋锥形环辗轧为研究对象,通过ABAQUS的VUAMP子程序开发,建立了实现以常每转进给量进给的芯辊运动闭环控制有限元仿真模型;进而模拟揭示了每转进给量、驱动辊半径和芯辊半径对型槽充填质量(充填率、型槽入口变形及其均匀性)的影响规律。结果表明:随着每转进给量增大,充填率先增大后减小,表明存在一个最佳的每转进给量最利于充填;随着每转进给量增大,型槽入口区域变形越小且分布越均匀,可有效抑制该区域产生裂纹缺陷;随着驱动辊半径增大,充填率逐渐减小,不利于型槽充填;随着芯辊半径增大,充填率逐渐增大,有利于型槽充填。

Filling rules in thin-walled and ribbed conical ring rolling for TC4 titanium alloy

The thin-walled and ribbed conical ring is one of the key underlying components widely used in aerospace industry. Being difficult to precision forming of cross-section of ring due to lack filling of groove profile is the bottleneck problem for this complex profiled ring rolling process. In this work, the key factors influencing the filling behavior, namely the feed amount per revolution, the radii of the main roll and idle roll are discussed. And taking a thin-walled and ribbed conical ring rolling process for TC4 titanium alloy as object, An FE model achieving close-loop control of idle roll with constant feed amount per revolution is established using VUAMP subroutine under ABAQUS environment. Then the influence rules of the feed amount per revolution and the radii of the main roll and idle roll on the filling quality, described by filling ratio and deformation and its uniformity at entrance of the groove profile, are disclosed by comprehensive simulations. The results show that: the filling ratio first increases and then decreases with the increase of feed amount per revolution, indicating that there is an optimum feed amount per revolution best beneficial to filling the groove profile; the deformation at the entrance of the groove profile is small and its distribution is uniform thus beneficial to avoiding the crack defect of that region with increasing feed amount per revolution; it is beneficial to filling the groove profile when decreasing the main roll's radius or increasing the idle roll's radius.