Effect of Micro-Voids on Plasticity in NiTi-Alloys

Jim Stian Olsen; Zhi Liang Zhang; Casper van der Eijk

doi:10.4028/www.scientific.net/AST.59.135

Paper Titles

Dynamic and Static Displacements of Atoms in B2-Phase of TiNi Alloy
p.108

Shape Memory Behavior in Some (Ti,Zr,Hf)₅₀(Ni,Cu)₅₀ Alloys Elaborated by Glass Devitrification
p.113

Engineering Aspects of Shape Memory Film Actuators and Sensors
p.119

Transformation/Deformation Behavior and its Constitutive Equation for Ti-Ni-Cu Shape Memory Alloy
p.129

Effect of Micro-Voids on Plasticity in NiTi-Alloys
p.135

Experimental Characterization of NiTi SMAs Thermomechanical Behaviour Using Temperature and Strain Full-Field Measurements
p.140

Thermomechanical Characterization of Shape Memory Alloy Tubular Composite Structures
p.150

Functional Properties of Ti-Ni-Based Shape Memory Alloys
p.156

On Functional Behavior of Strain-Aged Ti-Ni Alloy
p.162

HomeAdvances in Science and TechnologyAdvances in Science and Technology Vol. 59Effect of Micro-Voids on Plasticity in NiTi-Alloys

Effect of Micro-Voids on Plasticity in NiTi-Alloys

Abstract:

Recent experimental investigations have indicated that commercial NiTi superelastic alloys consist of particles and inclusions which can nucleate micro-voids. Almost no study on the effect of micro-voids has been carried out in the literature. In this study the effect of micro-voids and plasticity on the behaviour of a superelastic NiTi-alloy has been investigated. Axisymmetric unit cell models with different micro-void volume fractions have been analysed subjected to various stress triaxiality states. It is shown that the onset of plasticity is located at the void edge as the maximum stress initially occurs at this position. The finite element results indicate that the existence of micro-voids can reduce the re-centring capabilities in NiTi-alloys and that this effect should be taken into consideration of constitutive equations.