The effects of aging temperature on shape memory effect, mechanical propert
ies and microstructure of Fe-14Mn-5Si-8Cr-4Ni-0.2C shape memory alloy have
been studied. The results showed that the second phase particles rich in ch
romium, manganese and silicon precipitate during aging, and thereby increas
e the hardness and strength of the alloy. The shape recovery ratio can be r
emarkably improved by aging and a maximum value can be obtained at 1223 K,
which is 68% higher than that of the specimen in solid solution state. When
the aging temperature is below 1223 K, the amount of second phase particle
s increases as the aging temperature increases. The size of austenite grain
increases with increasing aging temperature. When the temperature is over
1223 K, the second phase particles can not precipitate. The lack of second
phase particles and the increase of grain size make the hardness and shape
recovery ratio drastically decrease, when the temperature is over 1223 K.