PSI - Issue 21

O. Berk Aytuna et al. / Procedia Structural Integrity 21 (2019) 120–129 O. Berk Aytuna et al. / Structural Integrity Procedia 00 (2019) 000 – 000

128

9

Loading direction

Shear Band

Fig. 9. EBSD analysis fromthe first formed shear band in uniaxial stretching.

4. Conclusions

Considerable PLC activity is present under both uniaxia l and biaxia l loading, where the PLC bands susta in the ma jority of overa ll stra in. Wh ile the deforma tion is heterogeneous with jerky load response, PLC bands do not change the overa ll formability of the materia l. However, shear stresses in uniaxia l loading promote full-sca le, sharp PLC bands stretching through the whole gage length of the samples. The repetit ive, sharp PLC bands evolve into the shear bands, which act as stress concentra tors and result in shear-based and ca tastrophic fracture (elonga ted dimples) of the samples. The deforma tion texture a lso has shear-based, cube-{001}<100> type components under uniaxia l loading. On the other hand, the shear bands are suppressed under biaxia l tension due to the lack of well-defined, sharp PLC bands. The samples are devoid of surface irregu larities and fa il by typica l ductile fracture. There is a lso a slight change in the fina l texture. Therefore, the biaxia l stra in path seems to be more favourable f or higher qua lity fina l products of ma teria ls demonstra tingPLC behavior.

Acknowledgements

This work was supported by European Commission’s Research Executive Agency’s Marie Skłodowska -Curie Actions – Career Integra tion Grant (FP7-PEOPLE-2013-CIG) with grant agreement #631774.

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