International Journal of Impact Engineering 28 (2003) 137–160 Response of hot isostatically pressed Ti–6Al–4V targets to normal impact by conical and blunt projectiles V.F. Nesterenko a, *, W. Goldsmith b , S.S. Indrakanti a , YaBei Gu a a University of California, San Diego, USA b University of California, Berkeley, USA Received 12 November 2001; received in revised form 7 June 2002 Abstract First experimental results are reported on ballistic performance of hot isostatically pressed (HIPed) texture-free targets using rapidly solidified powders of Ti–6Al–4V alloy (PREP and ELI-PREP). Plastic deformation by ball milling of these powders was performed to modify the microstructure of the materials. HIPed samples of 40 mm diameter and a thickness of 10–30 mm were shrinkfit into holes in larger diameter steel plates and struck by 50 caliber 601 cylindro-conical projectiles of hardness R c 60 with contact produced either by the conical or blunt surface. The mass of the projectile was about 31g and the initial velocities ranged from 300 to 450 m/s for flat-ended and from 900 to 950 m/s for the conical impacts. Comparative behavior of HIPed samples and standard samples made from commercially available Ti–6Al– 4V alloy MIL-T-9047G (bar, forged, annealed)—baseline material after impact with the same geometry was investigated. As a rule the final velocity of the plug for HIPed alloy was smaller (or no penetration was observed) than that of the baseline material for impact with the conical projectile. Slightly sloped cylindrical shear plugs were characteristic for both materials upon impact by flat projectiles and their velocities were used to evaluate the shear resistance of HIPed material to plugging. Comparative features of fracture in both cases are presented. The texture-free HIPed materials from powders demonstrated better ballistic performance than the baseline material and could be successfully used for ballistic applications. This is the first step in the development of high-gradient composite materials using a Ti–6Al–4V matrix from powder. r 2002 Elsevier Science Ltd. All rights reserved. Keywords: Hot isostatically pressed titanium alloys; Ballistic performance; Plugging; Shear localization *Corresponding author. Fax: +1-858-534-5698. E-mail address: vnesterenko@ucsd.edu (V.F. Nesterenko). 0734-743X/02/$-see front matter r 2002 Elsevier Science Ltd. All rights reserved. PII:S0734-743X(02)00052-0