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

Abstract

Ti 51 Ni 39 Cu 10 SMA is more suitable than Ti 50 Ni 50 SMA for use as a high damping alloy at room temperature because it has higher inherent internal friction and wider martensitic transformation temperature range. Experimental results show that tan values of both (IF PT +IF I ) B2!B19 and (IF PT +IF I ) B19!B19 0 of Ti 51 Ni 39 Cu 10 SMA are linearly proportional to 0 = 1=2 when the applied and 0 are within 10 Hz and 15 mm, respectively. Since defects and dislocations pin the martensite twin boundaries and obstruct their mobility, it is important to prevent the introduction of defects or dislocations into the solution-treated Ti 51 Ni 39 Cu 10 SMA to maintain its high inherent internal friction.

Damping Characteristics of Inherent and Intrinsic Internal Friction of Cu-Zn-Al Shape Memory Alloys

“…The decreasing Ms temperature and ∆H value can be attributed to the introduction of defects and dislocations during repeated thermal cycling, depressing the martensitic transformations of the Cu-7.5Zn-11Al SMA. Similar results were also observed in a previous study on the Ti 51 Ni 39 Cu 10 SMA [16].…”

“…Subsequently, the SMA is cooled to another set temperature and kept at a constant temperature to determine the IFPT and IFI values at that temperature. The aforementioned isothermal method can effectively and accurately determine the IFPT and IFI values of most SMAs [13][14][15][16][17][18][19][20][21][22]. However, this method is not suitable for the Cu-xZn-11Al SMAs in this study, because the repeated thermal cycling may influence the martensitic transformation properties of Cu-xZn-11Al SMAs, as demonstrated in Figure 5, which shows the DSC curve of the Cu-7.5Zn-11Al SMA for 10 repeated heating and cooling cycles.…”

“…Chang and Wu [13][14][15][16][17][18][19][20][21][22] have systematically studied the inherent and intrinsic internal friction (IF PT + IF I ) peaks for various SMAs by applying DMA using the isothermal method. According to their…”

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

“…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.…”

“…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.…”