TC4钛合金型材热挤压过程坯料温度演变规律研究

Research on devolvement rule of billet temperature of TC4 titanium alloy profile in hot extrusion process

采用数值模拟方法对TC4钛合金H形截面型材热挤压过程进行热力耦合分析,获得了坯料温度的分布情况及不同工艺参数对坯料温度的影响规律,结果表明:坯料温度进入稳定挤压阶段显著升高,产热与散热达到动态平衡状态;过渡圆角处坯料的温度明显高于坯料的其他部位;坯料的温升随挤压速度、摩擦因子、挤压比以及模具预热温度的增大而增大,但随坯料预热温度的增大而减小;而坯料的温降呈相反变化规律;最终获得优选挤压工艺方案。

The numerical simulation method was used to analysis the coupling thermal-mechanical behavior in H-section profile extrusion process of TC4 titanium alloy.The distribution of billet temperature and the effect regularity of different process parameters on the billet temperature were obtained.The results showed that the billet temperature increases significantly in the stable extrusion stage,heat production and heat radiation reached dynamic balance .Billet temperature of fillet was higher than that in other parts of the blank.With the increasing of extrusion speed,friction factor,extrusion ratio and the die preheating temperature,the billet temperature rise increased,while the billet temperature rise decreased with increasing of the preheating temperature of billet.The billet temperature drop changed on the contrary rules.The optimal extrusion process was obtained finally.