Internal friction of Ti–Ni–Cu ternary shape memory alloys

The Effect of Thermal Cycling on B2&rarr;B19&rarr;B19&prime; Transformations of Ti<SUB>50</SUB>Ni<SUB>40</SUB>Cu<SUB>10</SUB> Shape Memory Alloy by Dynamic Mechanical Analyzer

“…1) Among ternary TiNi-based SMAs, Ti 50 Ni 50Àx Cu x SMAs with x 5 30 at%, have been extensively examined from various aspects, such as the shape memory effect, [2][3][4] martensitic transformation behaviors, [5][6][7][8] mechanical characteristics, [9][10][11] microstructures, [12][13][14][15][16][17] internal friction, [18][19][20][21][22][23][24][25][26] etc. The transformation sequences of Ti 50 Ni 50Àx Cu x SMAs are B2 !B19 0 , B2 !B19 !B19 0 and B2 !B19 for x < 5, 5 5 x 5 20 and x > 20 at%, respectively.…”

“…Reported studies show, using the DMA test, there are three tan peaks for Ti 50 Ni 40 Cu 10 SMA: B2!B19 and B19!B19 0 transformation peaks, and a relaxation peak. 22,24,25) The former two tan peaks individually correspond to their storage modulus (E 0 ) minimums. 18,26,30) At the same time, the annealing recovery behavior of B2!B19 and B19!B19 0 transformations of severely cold-rolled and annealed Ti 50 Ni 40 Cu 10 alloy have also been studied by DMA.…”

Inherent Internal Friction of Ti<SUB>51</SUB>Ni<SUB>39</SUB>Cu<SUB>10</SUB> Shape Memory Alloy

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] When heating and cooling TiNi-based SMAs, there is an internal friction (tan ) peak with a storage modulus (E 0 ) minimum corresponding to the martensitic transformation. 5) In addition, it has been reported that the formation of premartensite R-phase in TiNi-based SMAs can strongly soften the storage modulus and thus augment the internal friction during transformation.…”

“…Therefore, most of the internal friction studies of TiNi-based SMAs focus on the damping characteristics of IF Tr . [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] However, for high damping materials, it is more important to consider the damping characteristics of IF PT and IF I since most engineering applications for these materials are used at a constant temperature (especially at room temperature) instead of a constant temperature rate. Here, the term (IF PT +IF I ) is referred to as the inherent internal friction.…”

Thermomechanical Analysis on Ti-Ni Shape Memory Helical Springs Under Cyclic Tensile Loads

“…These fields are strongly related with the annealing temperature and their interaction with other lattice defects 25 . Heat treatment and training process seriously affects the internal friction behavior in Ti-Ni alloys 26,27,28 . These events have an importance on the reconfiguration of Ti-Ni alloy defects, inducing modification that might change the material properties such as memory effect, damping capacity, strength, hardness, and others 26,27,28 .…”