TC21钛合金动态力学性能和抗弹性能的研究

Dynamic Mechanical Properties and Ballistic Performance of TC21 Alloy

摘要:

采用分离式霍普金森压杆和终点弹道实验装置，研究了α+β区和β区锻造的TC21钛合金的动态力学性能和抗弹性能。结果表明：在动态压缩试验条件下，α+β区锻造的TC21钛合金较之β区锻造的TC21钛合金具有更高的动态强度，而β区锻造的TC21钛合金的临界断裂应变更大，具有更好的动态塑性变形能力；在12.7 mm穿甲弹侵彻条件下，无论是α+β区还是β区锻造的TC21钛合金靶板的抗弹性能均与TC4钛合金靶板的抗弹性能相近，这可能是由于TC21钛合金和TC4钛合金靶板都易于发生绝热剪切破坏所导致。α+β区锻造的双态组织靶板的损伤模式为塑性扩孔导致的背部崩落破坏模式，β区锻造的片层组织靶板的损伤模式为脆性破碎模式；2种组织靶板的失效破坏均为绝热剪切带和其诱发的裂纹所导致。

Abstract:

The dynamic mechanical properties and ballistic impact property of α+β region and β region forged TC21 titanium alloy were studied using Split Hopkinson Pressure Bar and ballistic impact experiment. The results show that in the dynamic compression tests, the α+β region forged TC21 alloy has higher dynamic strength but lower dynamic failure strain than the β region forged TC21 alloy; in the ballistic impact experiment, both the α+β region and β region forged TC21 alloy do not demonstrate improved ballistic impact property as compared to the mill-annealed TC4 alloy, which is considered to be attributed to the similar failure mechanism analyzed. In the bimodal microstructure, spall fragments induced by ductile hole formation is the failure mode; while in the lamellar microstructures, the TC21 targets fail by the type of brittle fragmentation. Further post ballistic metallurgical observations find that failure mechanism involved in TC21 alloy is facilitated by the initiation and propagation of adiabatic shear bands and cracks induced by adiabatic shear bands.