Spall strength and fracture behavior of Ti-10V-2Fe-3Al alloy during one-dimensional shock loading

The spall fracture behavior of a typical metastable β titanium alloy, Ti-10V-2Fe-3Al, is systemically investigated during one-dimensional shock loading. Shock pressures over 14 GPa are achieved through a series of plate impact experiments. The results show that the shock-induced β-to-α″ martensite (SIM) phase transformation strongly influences the spall fracture behavior of this alloy. The spall strength of Ti-10V-2Fe-3Al ranges from 2.5 to 3.1 GPa, and drops by nearly 20% as the shock pressure exceeds 9 GPa. The acicular SIM phases provide additional nucleation sites and propagation paths for micro-damage, leading to the reduction of spall strength of Ti-10V-2Fe-3Al. Microstructural analyses also suggest that Ti-10V-2Fe-3Al is likely to spall in a mixed fracture manner containing both brittle and ductile failure features. The spall fracture surface of this alloy is very rough and consists of facets covered by ductile dimples.