کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1691744 1011330 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thermomechanical behavior of Ti-Ni shape memory alloy films deposited by DC magnetron sputtering
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سطوح، پوشش‌ها و فیلم‌ها
پیش نمایش صفحه اول مقاله
Thermomechanical behavior of Ti-Ni shape memory alloy films deposited by DC magnetron sputtering
چکیده انگلیسی
In this study, thermomechanical properties of titanium-nickel (Ti-Ni) shape memory alloy (SMA) films are investigated in order to derive constitutive relations. Ti-Ni SMA films, deposited by DC magnetron sputtering under controlled film composition, are characterized by uniaxial tensile tests. At room temperature (R.T.), Ti-Ni films having Ti contents less than 50 at% exhibit superelastic behavior, and those having Ti contents greater than 50 at% exhibit shape memory behavior. However, the Ni-53.2 at% Ti film fractured at a tensile strain of 0.8% because of an increase in brittleness with increasing Ti content. At elevated temperatures, Ti-Ni films having Ti contents of 50.2 to 52.6 at% undergo phase change from martensite to austenite. The Young's modulus of the Ti-Ni films depends on temperature at each phase, regardless of film composition. Film composition does, however, affect the measured material constants bA, bM, cA, and cM. Stress-strain curves calculated from the constructed constitutive equation closely agree with those obtained from tensile tests, for both the martensite and austenite phases. The constitutive equations are expected to find great utility in the design of Ti-Ni film-actuated microelectromechanical systems (MEMS).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Vacuum - Volume 80, Issue 7, 31 May 2006, Pages 726-731
نویسندگان
, , , ,