Hardening of copper and nickel alloys during pre-recrystallization annealing and softening during secondary deformation

Abstract

1. Secondary deformation of both metals and single- and two-phase alloys hardened as a result of the first deformation and pre-recrystallization annealing (or aging) results in considerable softening. 2. Softening is observed after slight reduction during secondary deformation (1–5%) and it mostly takes the form of a reduction to resistance to small plastic deformations. 3. Secondary plastic deformation after primary deformation in the same direction improves the elastic limit, but does not alter the anisotropy of the latter. A change in the direction of secondary deformation leads to alteration of the anisotropy of the elastic limit by increasing hardness in some directions and softening the alloy in others. 4. Secondary plastic deformation of alloys after primary deformation and pre-recrystallization annealing causes softening in all directions, although to a different degree. The nature of the anisotropy depends on the direction of the secondary deformation with respect to the original direction. 5. The Konobeevskii-Rovenskii effect is based on polygonization during pre-recrystallization annealing and disturbance of the polygonized substructure during secondary deformation. This effect is of a general nature and is natural both in pure metals and alloys; in alloys changes in fine structure are complicated by processes involving redistribution of the component atoms and therefore have a strong effect on the degree of hardening and softening.