Mechanical behavior of bilayer structures of Ti64 alloy and its composites with TiC or TiB under quasi-static and dynamic compression

Abstract

Bilayer structures of titanium alloy Ti-6Al-4V (Ti64) and metal matrix composites (MMC) on the base of this alloy reinforced with 5, and 10 % (vol.) of TiC or TiB particles were made using press-and-sinter Blended Elemental Powder Metallurgy (BEPM). The mechanical behavior of these structures was studied under quasi-static and high strain rate compression. Dynamic tests with compression velocity in the range 4–15 m/s (820–2880 s−1) were done using the split Hopkinson pressure bar (SHPB), whereas the quasi-static tests were performed with compression velocity of 0.0005 m/s (10−3 s−1). Stress–strain curves were obtained and the effect of phase composition, microstructure, and strain rate was analyzed and discussed. Current results were compared with previous studies conducted on homogeneous MMCs and Ti64 alloy tested in similar conditions. The deformation mechanism evaluated from the microstructure analysis of the samples was verified using in-situ high-speed camera recordings. Numerical simulation based on Finite Element Analysis was conducted to further investigate the behavior of the samples during the SHPB trials. Generalized scheme of the deformation and damage process of two-layer alloy/composites hybrids as a function of compression rate was proposed.