Texture Variations and Cyclic Softening Mechanisms on ZRY-4 at Room Temperature. Part I: Cyclic behavior

RAUL EDUARDO BOLMARO

REVISTA MATéRIA

Año: 2004 vol. 9 p. 280 - 287

1517-7076

The current paper presents fatigue experiments, and its interpretations, performed in Zry-4 to study cyclic softening behavior shown by this material at room temperature. Cyclic hardening is a usual phenomena in well-annealed materials while defect re-arrangement phenomena can lead to cyclic softening in previously deformation hardened materials. These phenomena are well studied in FCC and BCC materials. For HCP materials, like Zr and Ti alloys, the current information is much more scanty. The main purpose of the current paper is the analysis of reliability of some models proposing crystal reorientation during cyclic deformation as the main cause for cyclic softening. According to those models, that reorientation, or texture change, would induce softening due to diminishing Taylor factors because of prismatic slip system rotations. Part I of the paper presents, besides fatigue tests, analysis of the results and alternative models for interpretation. Part II shows texture experiments, together with complementary fatigue experiments, and self-consistent micromecanical simulations to evaluate expected fatigue behavior of the measured textures.