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The thermal stability of thin tungsten plates of four different thicknesses achieved by warm- and (in two cases) cold-rolling is investigated in the temperature range between 1325 °C to 1400 °C. Hardness testing of annealed specimens allows tracking the degradation of the mechanical properties and, indirectly, the involved restoration processes during the microstructural evolution. For all four tungsten plates, a concise description of both, isothermal and isochronal annealing treatments is achieved using well-established models for the kinetics of recovery and recrystallization. A systematic dependence of the recovery kinetics at different temperatures on the hardness loss during recovery at a particular temperature has been identified. For the recrystallization kinetics, an Avrami exponent of 2 is observed in general. On the other hand, the activation energies revealed for different characteristic times of the recrystallization process depend on the plate thickness (or more precisely, the defect density stored). These findings, in particular, an activation energy far below that of short circuit diffusion, indicate the possibility of persisting nucleation throughout annealing.

The annealing behavior of thin tungsten plates of four different thicknesses achieved by warm- and (in two cases) cold-rolling is investigated. Isothermal experiments at five different temperatures between 1300 °C to 1400 °C were performed. Hardness testing of annealed specimens allowed tracking the degradation of the mechanical properties and, indirectly, the microstructural evolution. Supplementary microscopical investigations of the microstructure in the as-received state as well as after annealing were performed to characterize the initial condition and to support the identification of the involved restoration processes. All four tungsten plates undergo microstructural restoration by recovery and recrystallization. The observed differences in their behavior were rationalized in terms of the identified differences in the microstructure in the as-received state, rather than their different initial thickness.