织构对TC1棒材动态冲击力学行为的影响

Effect of Texture on TC1 Rod Dynamic Impact Behavior

挤压成形是TC1棒材成形的主要手段。在挤压过程中,钛合金往往会形成织构,从而导致棒材的性能变化。本研究通过对比分析,研究了织构对动态冲击力学行为的影响。结果表明,在动态冲击过程中TC1合金出现了大量孪晶,且孪晶的数量随着冲击速度的提高而增加;0.4～0.7 MPa气压气压范围内冲击时,具有强织构的冲击试样动态屈服强度变化不明显,而具有弱织构的冲击试样动态屈服强度由于位错强化有所增加,表现出了应变率正效应;当气压增高到0.9MPa,由于更多孪晶的开动,具有强、弱织构的样品都出现负的应变速率效应。

Extrusion is the main method to obtain TC1 alloy rod. During titanium alloy rod extrusion, textures always form, which results in mechanical property change. In this paper, the effect of texture on mechanical performance under dynamic impact is investigated through comparison. Results show that, under the dynamic impact, lot of twins are activated in TC1 alloy, and their volume fraction rises with the increment of impact velocity. When the impact gas pressure is between 0. 4 MPa and 0. 7 MPa, the dynamic yield strength of specimens of intense texture doesn＇t change apparently, while strength increment in speci- mens of weak texture is more apparent, exhibiting positive strain rate sensitivity. When the impact gas pressure reaches 0. 9 MPa, both specimens of intense and weak textures perform the negative strain rate sensitivity due to the activity of more twinning.