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Vol.41, No.10, 645 ~ 652, 2003
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| Title |
| Dynamic Deformation and Ballistic Properties of Ti-6Al-4V Alloy 1. Ultra-high-speed Exploding Properties |
| 이유환 Lee Yu Hwan , 이동근 Lee Dong Geun , 이성학 Lee Seong Hag , 이종수 Lee Jong Su , 최준홍 Choe Jun Hong , 허선무 Heo Seon Mu |
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| Abstract |
| The effects of microstructural morphology on ultra-high-speed exploding properties of Ti-6Al-4V alloy were investigated in this study. Exploding bridge wire (EBW) test was conducted on equiaxed and bimodal microstructures, which were processed by different heat treatments. From the test, moving velocity of free surface vs time profiles were obtained to measure strength at Hugoniot elastic limit (HEL) and spall strength and to subsequently predict ballistic mass efficiency. The EBW results indicated that impact resistance of the bimodal microstructure was better than that of the equiaxed microstructure when the measured strength at HEL and spall strength were considered. It was also learned from the observation of fractured EBW specimens that fracture occurred by the initiation and propagation of long cracks in the equiaxed microstructure, whereas a number of microcracks were formed and connected each other in a zig-zag pattern to reduce the driving force for crack propagation in the bimodal microstructure. Since the EBW test helped experimentally estimate ultra-high-speed deformation and fracture behavior, it could be effectively used for the prediction of ballistic impact performance. |
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| Key Words |
| Bimodal microstructure, Equiaxed microstructure, Exploding bridge wire test, Spall strength, Hugoniot elastic limit |
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