Fatigue crack micromechanisms in a Cu-Zn-Al shape memory alloy with pseudo-elastic behavior
Journal Title: Frattura ed Integrità Strutturale - Year 2015, Vol 9, Issue 34
Abstract
Shape memory property characterizes the behavior of many Ti based and Cu based alloys (SMAs). In Cu-Zn-Al SMAs, the original shape recovering is due to a bcc phase that is stable at high temperature. After an appropriate cooling process, this phase (β-phase or austenitic phase) transforms reversibly into a B2 structure (transition phase) and, after a further cooling process or a plastic deformation, it transforms into a DO3 phase (martensitic phase). In β-Cu-Zn-Al SMAs, the martensitic transformation due to plastic deformation is not stable at room temperature: a high temperature “austenitization” process followed by a high speed cooling process allow to obtain a martensitic phase with a higher stability. In this work, a Cu-Zn-Al SMA in “as cast” conditions has been microstructurally and metallographically characterized by means of X-Ray diffraction and Light Optical Microscope (LOM) observations. Fatigue crack propagation resistance and damaging micromechanisms have been investigated corresponding to three different load ratios (R=0.10, 0.50 and 0.75).
Authors and Affiliations
Vittorio Di Cocco, Francesco Iacoviello, Stefano Natali, Andrea Brotzu
Keywords
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- EP ID EP95804
- DOI 10.3221/IGF-ESIS.34.46
- Views 70
- Downloads 0
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