Effect of precipitation on the shape memory effect of Ti50Ni25Cu25 melt-spun ribbon

Transformation temperature changes due to second phase precipitation in NiTi-based shape memory alloys

“…The available data are presented in Table 3. The precipitation of TiCu or Ti 2 (Cu,Ni) in NiTiCu alloys [15,17,19] and (TiNi þ Nb) þ (Ti,Nb) 2 Ni in NiTiNb alloys, formation of (Ti,V)Ni þ V 9 (Ti,Ni) in NiTiV alloys [13], and precipitation of (Ti,Zr) 2 Ni in NiTiZr alloys [14,16] lead to little (<15 C) or no variation of the M s . Aging of Ni 49 Ti 51 alloy has also been reported [20] to show almost no change in the M s temperature due to the presence of considerable amount of stable Ti 2 Ni precipitate in the asquenched alloy ( Table 3).…”

“…It has been shown that the martensitic transformation temperatures of NiTi-based alloys can be changed [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] as a result of aging. Tables 1 and 2 list the martensitic transformation temperatures of a number of solution-treated and aged NiTi-based alloys that experience a considerable change in M s temperature (>15 C).…”

Effect of Cu Content on Atomic Positions of Ti50Ni50−xCux Shape Memory Alloys Based on Density Functional Theory Calculations

“…The convergence tolerance of energy, maximum force, maximum stress and maximum displacement were set to be 5. The martensite crystal structures of TiNiCu alloys with different Cu contents have been reported [21,[29][30][31][32][33] and are listed in Table 1. The B19 and B19′ phases were observed in experiments, while the BCO structure was obtained from computational calculations.…”

Shape memory characteristics of as-spun and annealed Ti51Ni49 crystalline ribbons

“…Recently, melt-spinning technique has been utilized to fabricate amorphous or crystalline Ti-Ni binary and Ti-Ni-Cu ternary SMA ribbons for various applications. Among them, Ti 50 Ni 25 Cu 25 ribbon was widely studied because of its unique properties, such as small transformation hysteresis, low flow stress level in the martensite state, low sensitivity of the martensitic transformation start (Ms) temperature and easy fabrication for fully amorphous melt-spun ribbons [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These advantages make Ti 50 Ni 25 Cu 25 ribbon a good candidate for applications, such as actuator and sensor that require short response time at thermal cycle.…”