The mechanical and constitutive behaviour of as-received and irradiated Zr-2.5Nb pressure tube material under high rates of tensile strain

Mechanical tests were performed on as-received and irradiated Zr-2.5Nb pres sure tube material using a direct-tension split Hopkinson bar apparatus for temperatures in the range of 20 to 290 degrees C. A bi-linear dependence o f flow stress on log-strain rate was observed with the strength of both the as-received and irradiated material increasing as the strain rate increase d. The resulting data was used to derive parameters for the Johnson-Cook an d Zerilli-Armstrong HCP constitutive relations. Both relations were shown t o accurately predict the deformation behaviour of Zr-2.5Nb pressure tube ma terial.