ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The purpose of this work is to quantitatively clarify the shape memory behavior ofFe-Pd films containing ~30at%Pd by thermal cycling testing under various constant stresses.Fe-Pd films (4 $m thick) were deposited onto Si wafers with thermally formed 1$m-thick SiO2layer using a dual-source dc magnetron sputtering apparatus. The deposited films were allannealed at 900˚C for 60 min followed by iced water quenching. Perfect shape recovery wasobserved for Fe-30.0at%Pd film when the applied stress was lower than 300 MPa. The maximumrecoverable strain was ~0.6%. Fe-29.2at%Pd film, on the other hand, showed unrecovered strainafter thermal cycling even if the applied stress was 40 MPa. XRD measurements of theFe-29.2at% Pd film before and after thermal cycling revealed irreversible fcc-bct martensitictransformation that occurred during cooling process at a temperature around -80˚C. The criticalstress of Fe-Pd films, at which plastic deformation commences to occur, is higher for films with 30at% Pd than for films with 29.2 at% Pd, which is practically advantageous. The Ms temperature ofthese films is lower than room temperature when no bias stress is applied, while it becomes higherthan room temperature when appropriate bias stress is applied, obeying Clapeyron-Clausius law
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.3173.pdf
