By using polychromatic micro-beam synchrotron diffraction, together with electron and optical microscopy, a study was made of dislocation structure changes in Ni-based single crystal superalloys during impulse heating up to the melting point. It was shown that the distribution of the thermal gradient was not monotonic. The maximum value of the thermal gradient was observed in the heat-affected zone near to the fusion line. Depending upon the temperature, the formation of dislocations was accompanied by the partial or complete dissolution of γ’ particles in the matrix. Dislocations formed and multiplied due to thermal gradients, and their arrangement could be correlated with the temperature gradient field and with the dissolution and re-precipitation of γ’ particles.

Evolution of Dislocation Structure in the Heat Affected Zone of a Nickel-Based Single Crystal. O.M.Barabash, J.A.Horton, S.S.Babu, J.M.Vitek, S.A.David, J.W.Park, G.E.Ice, R.I.Barabash: Journal of Applied Physics, 2004, 96[7], 3673-9