Linear recovery property of TiNi shape memory alloy and its modification by heat treatment

A new concept of linear recovery behavior in TiNi shape memory alloy(SMA) has been proposed,and its property index has been defined.Through testing the heat reversion curves we study the TiNi SMA spring's linear reversion effect under different heat treatments.The results indicated that the proper heat treatment technology can modify obviously the linear recovery properties of TiNi SMA spring.The optimal heat treatment technology is 550℃+AC:the proportion of linear reversion(PL) was increased from 56% to 92%,the ratio of linear reversion(PL) was increased from 54% to 83%,and the temperature range of the linear reversion(TW) was enlarged from 4℃ to 6℃.