Dynamic Behavior Evaluation of Martensitic Transformation in Cu-Al-Ni Shape Memory Alloy Using Acoustic Emission Simulation by FEM

Dynamic behavior of two types of martensitic transformations during tensile deformation of Cu-Al-Ni shape memory alloy single crystal has been investigated using an acoustic emission waveform analysis. Two kinds of martensitic transformations consist of β1 ⇔ β1′ (structural change of DO3 to 18R) and β1 ⇒ γ1′ (structural change of DO3 to 2H), each of which is called super-elastic and thermo-elastic martensitic transformations, respectively. These two types of martensitic transformations could be obtained during tensile deformation because of different heat treatment. The rise time at the source (the source rise time) in finite elastic solid by the modified Takashima’s method was analyzed using the acoustic emission waveform detected during the martensitic transformation. The mean source rise time to the γ1′ phase was smaller than that to the β1′ phase before yielding and became the same after yielding. The former result means that the nucleation of the γ1′ phase is faster than that of the β1′ phase because of different crystallographic structure. The latter result is that the growth rate of the γ1′ phase is the same as that of the β1′ phase.

Download Full-text

Acoustic Emission as a Probe of the Kinetics of the Martensitic Transformation in a Shape Memory Alloy

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.47.607 ◽

2006 ◽

Vol 47 (3) ◽

pp. 607-611 ◽

Cited By ~ 4

Author(s):

Stefanus Matheus Cornelis van Bohemen ◽

Jilt Sietsma ◽

Roumen Petrov ◽

Marcel Joseph Marie Hermans ◽

Ian Malcom Richardson

Keyword(s):

Acoustic Emission ◽

Martensitic Transformation ◽

Shape Memory Alloy ◽

Shape Memory ◽

Kinetics Of

Download Full-text

Micro and Macromechanical Study of Stress-Induced Martensitic Transformation in a Cu-Al-Be Polycrystalline Shape Memory Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.509.87 ◽

2006 ◽

Vol 509 ◽

pp. 87-92 ◽

Cited By ~ 2

Author(s):

F.M. Sánchez ◽

G. Pulos

Keyword(s):

Martensitic Transformation ◽

Shape Memory Alloy ◽

Shape Memory ◽

Vector Fields ◽

Displacement Vector ◽

Optical Microscope ◽

Image Sequences ◽

Tension Test ◽

Loading Device ◽

Stress States

An experimental investigation of the micro and macromechanical stress-induced martensitic transformation in a Cu-Al-Be polycrystalline shape memory alloy is undertaken using a uniaxial tension test. Digital images are acquired at different stress states. The image sequences are analyzed to estimate the optical flow to get displacement vector fields. The experiments are carried out on a miniature hydraulic loading device mounted under an optical microscope. The stress-strain curves and associated images show stress-induced martensitic transformation in specific grains. Displacement vector fields for the polycrystalline shape memory alloy are obtained. They are inhomogeneous due to the martensitic transformation and inter-granular interactions.

Download Full-text