Internal friction peak due to hydrogen in copper

Copper loaded with 5 at ppm hydrogen exhibits an internal friction relaxation peak at 150 K (period of the alternative stress: 2 s). This peak, called PH, can be interpreted as a consequence of the interaction between dislocations and hydrogen atoms and can be described by means of a thermomechanical break-away model. The main features of PH are discussed in connection with cold-work ratio, hydrogen content (in the range 0 to 5 × 10−6), strain amplitude (in the range 10−5 to 10−4), and conditions of growth and annealing. On a mis en evidence un pic de frottement interieur a 150 K (periode de la sollicitation alternative: 2 s) sur du cuivre contenant 5 at ppm d'hydrogene. Ce pic, note PH, est interprete comme une consequence de l'interaction entre les dislocations et l'hydrogene et il est decrit a l'aide d'un modele de desancrage thermomecanique. On discute les caracteristiques essentielles de PH en liaison avec le taux d'ecrouissage, la teneur en hydrogene (entre 0 et 5 × 10−6), l'amplitude de deformation (entre 10−5 et 10−4), et les conditions de croissance et de recuit.