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The influence of the densities of the pyramidal and basal “forest” dislocations in Zn crystals on the value of the yield stress τk for the boundaries of the single twin layers, on the creep rate of the twin boundaries, v, and on the total displacement of the twin boundaries, δ, by pulsed loading was studied. It is shown that τk rises with the increase of the “forest” dislocation density in the {1122”︁ 〈1123〉 system, and v and δ decrease. It means that the pyramidal dislocations were the places of “pinning” for the twin dislocations. The increase of the “forest” dislocation density in the {0001} 〈1120〉 system leads to an increase of τk but v and δ also increase. The latter fact shows that the basal dislocations were not only the places of “pinning” for the twin dislocations but also the sources of them. The transition of the basal dislocations from the matrix in the twin was accompanied by the formation of perfect dislocations in the twin in the glide system {1100} 〈1123〉 and zonal twin dislocations on the boundary. The activation volumes for the process of creep depending on the densities of the pyramidal and basal “forest” dislocations were calculated from the values of the creep rate for the twin boundaries by different stresses.

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