Investigation on dynamic compressive properties of carbon fiber cloth-reinforced titanium alloy

Cu-coated carbon fiber cloth/Ti-6Al-4V composite (Cu-C_f/TC4) and uncoated-C_f/TC4 were fabricated by spark plasma sintering (SPS) method. The microstructure and dynamic compression properties of the C_f/TC4 composites were investigated. Results show that the matrix-fiber interfacial bonging in uncoated-C_f/TC4 is weaker than in Cu-C_f/TC4. Moreover, lamellar TiC exists throughout the TC4 matrix in uncoated-C_f/TC4, while there is no TiC generated in TC4 matrix of Cu-C_f/TC4. Dynamic compressive tests indicate the stress-strain curves of Cu-C_f/TC4 and uncoated-C_f/TC4 show no difference at a strain rate of 2500 s^-1, while show significant difference at a strain rate of 4800 s^-1. Further investigations find: (1) at a strain rate of 2500 s^-1, the reinforcement effect of C_f on Cu-C_f/TC4 is similar to TiC on uncoated-C_f/TC4, explaining the exact similarity in compressive property of Cu-C_f/TC4 and uncoated-Cf/TC4; (2) at a strain rate of 4800 s^-1 the reinforcement effect of C_f on Cu-C_f/TC4 is far more than TiC on uncoated-C_f/TC4, explaining the higher compressive strength of Cu-C_f/TC4; moreover, multiple debonding of carbon fiber and its squeezing into TC4 matrix constitute an important energy absorption mechanism for uncoated-C_f/TC4, explaining the better plasticity of uncoated-C_f/TC4.