Shape memory alloy with ductility and a process of making the same

Abstract

A Ti—Ni shape memory alloy with ductility, including Ti of 50˜66atomic % in a composition, and in which precipitation of Ti 2 Ni phases at grain boundaries is suppressed.

What is claimed is:  
     
         1 . A Ti—Ni shape memory alloy with ductility, including Ti of 50˜66 atomic % in a composition, and in which precipitation of Ti 2 Ni phases at grain boundaries is suppressed.  
     
     
         2 . The Ti—Ni shape memory alloy with ductility as claimed in  claim 1 , wherein the Ti—Ni shape memory alloy exhibits plastic strain of not less than 15% at room temperature.  
     
     
         3 . The Ti—Ni shape memory alloy with ductility as claimed in  claim 1 , wherein the Ti—Ni shape memory alloy is produced as a thin film.  
     
     
         4 . The Ti—Ni shape memory alloy with ductility as claimed in  claim 2 , wherein the Ti—Ni shape memory alloy is produced as a thin film.  
     
     
         5 . A making process of a Ti—Ni shape memory alloy with ductility, including Ti of 50˜66 atomic % in a composition, which comprises the steps of crystallizing an amorphous Ti—Ni alloy at 600˜900K for less than an hour and then cooling down to room temperature slowly in order to suppress precipitation of Ti 2 Ni phases at grain boundaries.  
     
     
         6 . The making process as claimed in  claim 5 , wherein crystallization is conducted at 800˜900K for less than 10 minutes.  
     
     
         7 . The making process as claimed in  claim 5 , wherein the Ti—Ni shape memory alloy is produced as a thin film.  
     
     
         8 . The making process as claimed in  claim 6 , wherein the Ti—Ni shape memory alloy is produced as a thin film.