钛合金薄板高低速塑性行为及组织性能的实验研究

Investigation on the static and dynamic plastic behavior and the texture and properties of titanium sheet

针对钛合金在航天军工领域的服役特点,利用万能材料试验机以及Hopkinson压杆对某α+β双相钛合金薄板静态及动态材料行为进行研究,给出了不同热处理制度下材料的应力应变关系,观察了材料的微观组织特征。研究结果表明,对于α+β双相钛合金薄板,垂直轧向的屈服强度高于平行轧向屈服强度,材料无明显加工硬化,屈服强度拉压不对称;高应变速率加载情况下材料并无明显应变强化,材料破坏表现为沿45°方向的剪断型破坏;强迫剪切过程中热处理前后均无明显绝热剪切带产生,材料发生沿45°方向流动,表现出良好塑性。

Focused on the special working condition of Titanium in aerospace and military application,the static and dynamic behavior of a two-phase α＋β titanium sheet was investigated by experiments with heat-treatment.The results show that for the current α＋β two-phase titanium,the yield strength along transverse direction is higher than that along rolling direction,but when the strain is over 3% both hardening curves coincide together and the increase of stress with deformation is linear.Compressive yield strength is greater than the tensile yield strength,which shows asymmetry in tension and compression.Current heat-treatment didn＇t influence the compressive strength greatly and when the deformation is over 0.23,shear failure occurs along 45 degrees of sample.With high strain rate loading,the strain hardening effect is not obvious and the fracture is in the shearing direction.For the forced shearing with or without heat-treatment,the metal flows along 45 degrees and shows good plasticity,while adiabatic shear bands is not found neither before or after heat-treatment.