This question emerges from the former Q&A : What are subgrains?
If this issue is not understood, we suggest the following: • Characterize the subboundaries formed in deformed specimens in constant strain rate tests above 0.8 Tm (Temperature regime 3) in copper, • Compare the subboundaries formed in temperature regime 3 with those described for temperature regime 2 (0.5Tm to 0.8 Tm) in the featured paper >, • Differences between these may be associated with climb(open issue). For the definition of the temperature regimes, please refer to: P.N.B. Anongba, J. Bonneville, and J.-L. Martin, Hardening Stages of [112] Copper Single Crystals at Intermediate and High Temperatures, Acta Metall. Mater., 41 (1993) Part I: Mechanical Behaviour (pp. 2897-2906), Part II: Slip Systems and Microstructures (pp. 2907-2922).
I suggest an additional experiment: plastically bend the single crystal beam at low temperature, then unload and do annealing at constant temperature (say, 0.5 Tm). Observe the low angle tilt boundaries between polygons. If possible, measure the density of dislocations inside the polygons to see, whether some of them remain within the polygons.
I have no experience on the substructure formed after the bending of single crystal beams. May be the structure is easier to study by TEM. So experiments in this direction should be considered seriously in view of the theory available. Also we have to find a convenient orientation of the specimen.
I am missing something: why climb seems to be so important to low angle tilt boundary and polygons in Prof. Khanh Chau Le theoretical view. From my own experience, cross slip is more effective at lower temperature (0.5 Tm to 0.8 Tm) in the substructure formation than climb in copper. So why not consider cross slip?
Cross slip is surely one of important factors influencing the substructure formation. However, the issue was whether or not dislocation climb plays some role at the formation of low angle tilt boundaries. The clear answer may be found by studying the polygonization.
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