NEW METHOD FOR EVALUATING GIBBS FREE ENERGYIN SHAPE MEMORY ALLOYS

Abstract

Smart materials or shape memory alloys have a wide range of important
applications in our time, They are used in the medical field, the main parts
that are used in surgical operations by computers made of these materials,
because of unique properties of this kind of alloys where it can
automatically retrieve forms and accurately with the change of ambient
temperature or with the change of pressure imposed on it or a magnetic field
(or electric) Surrounding. Thus, it becomes possible for a specialist to give
the desired shape during the development of the alloy in the vicinity of a
temperature equal to the temperature of the human body and then pull this
alloy from the oven then in room temperature it will have the ingot form
would facilitate the introduction into the patient's body through the events of
wound smaller than if the process was conducted through regular, As in
modern operations to widen the arteries and directed by gravel from the
kidneys eliminate malignant tumors and other surgical procedures other. As
also used in manufacturing aircraft wings where the wing changes shape
with changing temperatures of the upper atmosphere. Also used in the very
small motor industry because of the ability of its molecules to interact with
the surrounding magnetic field or by changing the pressure imposed on it.
A new way for the evaluation of the Gibbs free energy for the shape
memory alloys at any point within the specimen at the end of the
transformation is developed.
In contrast with our previous model , which is limited in practice to
the whole specimen , this model is valid for length scales specified by
the a, b, c for the parent and the emberio lattice and controlled by the
transformation matrices.