1. Fracture of notched round-bar NiTi-specimens
- Author
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Olsen, J.S., Zhang, Z.L., Lu, H., and van der Eijk, C.
- Subjects
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ROUND barns , *FRACTURE mechanics , *NICKEL compounds , *FRACTOGRAPHY , *SURFACES (Physics) , *SCATTERING (Physics) - Abstract
Abstract: In this work fractography has been used to characterize the fracture surfaces of superelastic, notched round-bar NiTi-specimens. Several fractography studies have been performed for conventional materials, but only few studies have been conducted on NiTi-alloys. The aim of this work is to investigate the effect of semi-circular notches on the fracture behavior of NiTi. The main results indicate that the fracture process is a mixture of cleavage and micro-void coalescence, and that decreasing the notch-radius leads to a loss of ductility which manifests in a reduced fracture strain. Within the range of notches studied in this work, we can observe a transition from high scatter to low scatter in the fracture strain when reducing the notch-radius. By combining fractography studies, finite element analyses and the Rice–Tracey void-growth model, it is argued that fracture is most likely initiated close to the notch for all notch-radii studied herein, and that cleavage or quasi cleavage is the dominating fracture mechanism. [Copyright &y& Elsevier]
- Published
- 2012
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