Internal friction and dynamic Young modulus measurements have been performed in the temperature range 80–350 K on the Ti6Al4V alloy and a Ti6Al4V–SiC f composite reinforced by unidirectional SiC fibers (SCS-6). A vibrating reed apparatus operating at low strain amplitude (< 10− 5) in the frequency range 10 2–10 4 Hz was employed. Two anelastic relaxation peaks: P 1, P 2 have been observed in both materials. The peak temperatures at 1 kHz are respectively 120 K and 250 K. The fiber reinforced composite in the same temperature range shows a higher background damping and enhanced relaxation strength for the P 1 peak. The activation energy and frequency factors evaluated from the peak temperature shift with frequency are respectively H 1= 0.21±0.02 eV, H 2= 0.50±0.03 eV and τ 01− 1= 10 15 s− 1, τ 02− 1= 10 12 s− 1. Both peaks position and relaxation strength depend on hydrogen content and …