Dynamic response and microstructure evolution of titanium alloy plates under low-velocity impact

Abstract

This paper presents an experimental investigation into the dynamic response and microstructure evolution of titanium alloy plates subjected to low-velocity impact load. The impact experiments with different impact energies were designed and conducted. The effects of impact energy on the impact response curves and the interested impact resistance were analyzed. The macro deformation/failure mechanisms were examined by using digital microscope. The microstructure evolution induced by the variation of impact energy was further elaborated via scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) technique. On the basis of same impact condition, the impact behaviors of titanium alloy specimens were compared with the ones of woven carbon fiber reinforced composite laminates (CFRP) with the same areal density. The results show that the impact response of titanium alloy specimens is mainly characterized with linear loading stage, nonlinear loading stage and unloading stage. Linear relationships of peak impact force, maximum impactor displacement and absorbed energy with impact energy are found. The increase of impact energy will increase the content of α phase due to the difference in plastic deformation resistance of microstructures. Different impact behaviors appeared for titanium alloy specimens and CFRP specimens. CFRP specimens exhibited superior impact resistance with lower peak impact force and higher energy absorption relative to titanium alloy specimens.