Microstructure Evolution and Dynamic Mechan-ical Properties of Laser Additive Manufacturing Ti-6Al-4V Under High Strain Rate

• 作者: Changhong Wang Hao Wang Jianbo Lei Jie Tang Jun Wu Lei Zhu Lingchao Qin Mingming Liu Ning Wang Tao Wang
• 来源期刊: 北京理工大学学报（英文版）
• 学科: 工学
• 年，卷（期）: 2020,（4）
• 页码范围: 568-580
• 页数: 13页
• 分类号: TG174.4
• 语种: 英文
• DOI: 10.15918/j.jbit1004-0579.20064

摘要

The dynamic mechanical properties of the Ti-6Al-4V (TC4) alloy prepared by laser ad-ditive manufacturing (LAM-TC4) under the high strain rate (HSR) are proposed. The dynamic compression experiments of LAM-TC4 are conducted with the split Hopkinson pressure bar (SHPB) equipment. The results show that as the strain rate increases, the widths of the adiabatic shear band (ASB), the micro-hardness, the degree of grain refinement near the ASB, and the dislo-cation density of grains grow gradually. Moreover, the increase of dislocation density of grains is the root factor in enhancing the yield strength of LAM-TC4. Meanwhile, the heat produced from the distortion and dislocations of grains promotes the heat softening effect favorable for the recrystalliz-ation of grains, resulting in the grain refinement of ASB. Furthermore, the contrastive analysis between LAM-TC4 and TC4 prepared by forging (F-TC4) indicates that under the HSR, the yield strength of LAM-TC4 is higher than that of F-TC4.