The effect of notches on the fatigue behavior in NiTi shape memory alloys

Fatigue experiments have been performed on superelastic NiTi double-notched plate form specimens with different notch types and sizes. The fatigue loading was controlled by the average stress at the minimum cross-section. The fatigue life as well as the fatigue fracture surface has been investigated...

Full description

Saved in:
Bibliographic Details
Published in:Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2014-07, Vol.610, p.188-196
Main Authors: Wang, X.M., Cao, W., Deng, C.H., Liu, H., Pfetzing-Micklich, J., Yue, Z.F.
Format: Article
Language:English
Subjects:
Applied sciences
Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder
Cross-disciplinary physics: materials science
rheology
Exact sciences and technology
Fatigue
Fatigue (materials)
Fatigue failure
Fatigue life
Fracture mechanics
Fractures
Intermetallic compounds
Intermetallics
Martensitic transformations
Materials science
Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology
Metals. Metallurgy
Nickel titanides
NiTi
Notches
Phase diagrams and microstructures developed by solidification and solid-solid phase transformations
Physics
SEM
Shape memory alloys
Superelasticity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Fatigue experiments have been performed on superelastic NiTi double-notched plate form specimens with different notch types and sizes. The fatigue loading was controlled by the average stress at the minimum cross-section. The fatigue life as well as the fatigue fracture surface has been investigated in detail. The fatigue life decreases from specimens without notches, to specimens with semi-circular notches followed by v-type notched specimens. Specimens with crack notches show the shortest fatigue lives. The fatigue life decreases with increasing the notch acuity. Not only notch type but also notch size affects the fatigue life under the same macro-average stress. The fatigue fracture surfaces are quite similar to those of the conventional ductile materials with crack initiation, propagation and final fracture area. Typical characteristics of low cycle fatigue surfaces such as multi-fatigue crack initiation sites, weak striations and tyre-like patterns were found. Finite element (FE) simulations were performed to investigate the stress and phase transformation distributions in order to explain and understand the experimental results.
ISSN:0921-5093
1873-4936
DOI:10.1016/j.msea.2014.04.109