带台阶式齿轮槽钛合金沉头螺栓镦制成形仿真优化

Simulation and optimization on hot upsetting of titanium alloy countersunk head bolts with stepped gear grooves

针对带台阶式齿轮槽钛合金100°沉头螺栓镦制过程易出现冲针套台阶断裂失效的问题,进行Deform-3D有限元仿真优化,通过改变预成形坯件结构来改善精冲终成形时的受力情况,以达到延长精冲模使用寿命的目的。结果表明:将原成形方案改为沉头带锥孔的方案,可以改变终成形时材料与冲针套台阶的接触顺序,减小冲针套台阶与材料的接触时间和其所受应力,缩小冲针套台阶的应力集中区域;通过仿真得出优化成形方案,即最佳成形参数为α=100°、d=Φ8.5 mm和β=140°。最后,根据实际镦制情况对仿真得出的参数进行了调整,调整后的最佳成形参数为α=100°、d=Φ6.5 mm和β=140°,并且在该参数下得到了较好的成形结果,验证了该方案的可行性。

For the problem that the step fracture failure of punching needle sleeve was prone to occur during the hot upsetting process for titanium alloy 100°countersunk head bolt with stepped gear groove,and the Deform-3 D finite element simulation optimization was carried out.Then,the stress condition during the final forming of fine blanking was improved by changing the structure of preformed blank in order to achieve the purpose of prolonging the service life of fine blanking die.The results show that changing the original forming scheme to the scheme with countersunk head and tapered hole can change the contact sequence between the material and the steps of punching needle sleeve during the final forming,reduce the contact time between the steps of punching needle sleeve and the material and its stress,and reduce the stress concentration area for the steps of punching needle sleeve.Through simulation,it is concluded that the optimal forming parameters of the optimized forming scheme areα=100°,d=Φ8.5 mm andβ=140°.Finally,the parameters obtained from the simulation are adjusted according to the actual upsetting situation,and the adjusted optimal forming parameters areα=100°,d=Φ6.5 mm andβ=140°.Under the above parameters,the better forming results are obtained,which proves the feasibility of the scheme.