Multistage Development of Müller-Achenbach model for Shape Memory Alloy
Simin Ataollahi Oshkovr, Nik Abdullah Nik Mohamed, Che Husna Azhari, Siavash Talebi Taher and Azim Ataollahi Oshkour
DOI : 10.3844/ajeassp.2008.248.251
American Journal of Engineering and Applied Sciences
Volume 1, Issue 4
This research focused on the conceptual development of constitutive Müller-Achenbach model and proceeds to construct a model based on phase transition under changing temperature and load for variants of martensite in shape memory alloy CuAlNi (Copper-aluminum-nickel). Problem statement: Motivation of this research is rare information of a variant of martensite phase (M++) and prediction of the shape recovery of shape memory alloy in this stage of transformation. Approach: The mathematical equations proposed a prediction of stability of Austenite phases and extend it to multistage martensitic phase transformation. These phase transformations occurred by loading on the material. Equations described free energy landscape in CuAlNi shape memory alloys at low (260K) and high temperature (440K). The model evaluated the free energy due to the phase transformation between the austenite and multistage martensitic structures. Results: Results for M++ phase showed decrease in temperature from 440K to 260K presented decrease in stress approximately from 1 kN to 0.4kN and free energy from 5 kJ/kg to 0.1 kJ/kg. Equations have been solved and plotted by software programmed in MATLAB. Conclusions/Recommendations: The model which has derived focused on homogeneous shape memory alloys, but future performance requirements will most likely be met with heterogeneous materials. Therefore, simulation models for heterogeneous materials must be developed.
© 2008 Simin Ataollahi Oshkovr, Nik Abdullah Nik Mohamed, Che Husna Azhari, Siavash Talebi Taher and Azim Ataollahi Oshkour. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.