Preliminary results of stress recovery of constrained NiTi SMA wire for aerospace applications

Author(s):Show less -

Santos, Julio Cesar ; Da Silva, Antunes Andre ; Pinheiro, Afonso Paulo Monteiro ; Kabayama, Leonardo Kyo ; Rigo, Odair Dona ; Otubo, Jorge ; Gomes, RM ; DeBarros, S ; Torres, SM ; DeLima, SJG ; Melo, TAA ; Buono, VTL

• Document type: Journal article
• Source: Materials Science Forum; v. 643, p. 2-pg., 2010-01-01.

Abstract

The rocket propellant ignition system uses electro-explosive device actuated by wire electrode. Those wires are usually made by Fe-Ni based alloy with controlled thermal expansion inserted into a ceramic feed-through and are connected to thin resistive wire which is heated through the passage of an electrical current for propellant ignition. The contact between ceramic feed-through and wires should be reliable since sometimes it could fail. A novel alternative process is to use SMA wires taking into account the shape recovery effect constraining the wire inside the feed-through. The recovery stress of 326 MPa for 4% pre-strain should be enough to constrain the wire inside the feed-trough avoiding the gas leakage. (AU)