TY - JOUR A1 - Agudo Jácome, Leonardo A1 - Nörtershäuser, P. A1 - Somsen, C. A1 - Dlouhý, A. A1 - Eggeler, G. T1 - On the nature of gamma' phase cutting and its effect on high temperature and low stress creep anisotropy of Ni-base single crystal superalloys T2 - Acta materialia N2 - The creep anisotropy of the single crystal superalloy LEK 94 deformed in tension along [0 0 1] and [1 1 0] directions at 1293 K and 160 MPa was investigated. Elementary microstructural processes which are responsible for a higher increase in creep rates with strain during [1 1 0] as compared to [0 0 1] tensile loading were identified. [1 1 0] tensile creep is associated with a higher number of γ' phase cutting events, where two dislocations with equal Burgers vectors of type <1 1 0> jointly shear the γ' phase. The resulting <2 2 0>-type superdislocation can move by glide. In contrast, during [0 0 1] tensile loading, two dislocations with different <1 1 0>-type Burgers vectors must combine for γ' phase cutting. The resulting <2 0 0>-type superdislocations can only move by a combination of glide and climb. The evolution of dislocation networks during creep determines the nature of the γ' phase cutting events. The higher [1 1 0] creep rates at strains exceeding 2% result from a combination of a higher number of cutting events (density of mobile dislocations in γ') and a higher superdislocation mobility (<2 2 0> glide) in the γ' phase. PB - Elsevier Science CY - Kidlington KW - Ni-base single crystal superalloys KW - Creep KW - Anisotropy KW - Dislocation KW - Rafting PY - 2014 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/30387 AN - OPUS4-30387 SN - 1359-6454 SN - 1873-2453 VL - 69 SP - 246 EP - 264 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany