Study of Thermal Properties of NiTi Thin Film Shape Memory Alloy

number: 
1885
إنجليزية
department: 
Degree: 
Author: 
Hadeel Thamer Khudhair
Supervisor: 
Dr. Emad K. Al-Shakarchi
year: 
2008

Shape memory alloys (SMA) or intelligent material, which are also called smart material, are a group of metallic alloys that undergo phase transformation from Austenite to Martensite when heated or subjected to appropriate stresses. After cooling or removing the stress, they have the ability to remember their previous structure and return to it.The concern of this study is on the thermal properties of NiTi thin film and its substrate as an attempt to understand the behavior occurring  in the thin film slide represented by breaking it at certain values of voltage, current and substrate temperature (Ts). We have selected NiTi alloy because of its important medical and industrial applications.Thermal conductivity and heat capacity of NiTi thin film have been calculated theoretically and the thermal conductivity and heat capacity of glass substrate are measured experimentally. The cause of breaking in the thin film slide is the result of large difference in the thermal properties represented by thermal conductivity and heat capacity between the NiTi thin film and glass substrate. This is because the glass can not bear the high amount of heating energy resulting during the phase transformation process between Austenite and Martensite which exerts on the thin film slide.