Change in the substructure of cold worked aluminum crystals on subsequent heating

Abstract

In this research, a relationship has been established between the polygonization of aluminum single crystals on annealing and the hardening curve for single crystals of fec metals. It has been shown by the Guinier-Tennevin X-ray focusing method that only high-temperature (600–640 °C) polygonization develops on annealing single crystals of pure (99.99%) aluminum cold worked by extension at −196 °C within stages I and II of the hardening curve. In crystals cold worked to the end of stage II, and in the whole of stage III, the polygonization process takes place at an appreciable rate even during “low-temperature” (450 °C) annealing. Subsequent high-temperature annealing of these single crystals leads to an increase in the degree of perfection of the crystal lattice of the subgrains whose formation began during low-temperature annealing.