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

Abstract

Damping properties of the inherent and intrinsic internal friction peaks (IF PT + IF I ) of 7.5, 8.0, 8.5, and 9.0 wt. %) shape memory alloys (SMAs) were investigated by using dynamic mechanical analysis. The Cu-7.5Zn-11Al, Cu-8.0Zn-11Al, and Cu-8.5Zn-11Al SMAs with (IF PT + IF I ) β 3 (L2 1 )→γ 3 (2H) peaks exhibit higher damping capacity than the Cu-7.0Zn-11Al SMA with a (IF PT + IF I ) β 3 (L2 1 )→γ 3 (2H) peak, because the γ 3 martensite phase possesses a 2H type structure with abundant movable twin boundaries, while the β 3 phase possesses an 18R structure with stacking faults. The Cu-9.0Zn-11Al SMA also possesses a (IF PT + IF I ) β 3 (L2 1 )→γ 3 (2H) peak but exhibits low damping capacity because the formation of γ phase precipitates inhibits martensitic transformation. The Cu-8.0Zn-11Al SMA was found to be a promising candidate for practical high-damping applications because of its high (IF PT + IF I ) peak with tan δ > 0.05 around room temperature.

Novel Quaternary CuAlZnMg High Temperature Shape Memory Alloy (HTSMA) Fabricated by Minor Batch of Zn and Mg Additions

“…3. The main or the highest intensity peak is β1'(128) martensite peak and the others are β1' martensite peaks of (122), ( 202), (0018),( 1210) and (042) according to the reference works of [37,38,42,49]. The alloy has a polycrystalline structure.…”

“…Although there are many studies been done on ternary CuZnAl SMAs [5,23,[37][38][39] and some also on CuAlZn SMAs [27,40], there is no any Mg incorporated quaternary CuAlZnMg SMA work in the available literature. In this work, a CuAlZnMg SMA with a minor batch of Zn and Mg additives was produced by arc melting method.…”

The Effect of Heat Treatment on Damping Capacity and Mechanical Properties of CuAlNi Shape Memory Alloy

“…The β 1′ martensite appears as lath type martensite with thin plates (needle-like morphology) and γ 1′ is thicker with plate-like morphology (coarse variants) [ 5 ]. It has been reported that the γ 1′ martensite with a 2H structure in the CuZnAl alloy has abundant movable twins [ 10 ].…”

“…Hysteresis observed in pseudoelasticity is one of the energy dissipation manifestations [ 8 ]. According to the results of Wu et al [ 10 ], in Cu-xZn-11Al (x = 7.0, 7.5, 8.0, 8.5, and 9.0 wt.%), a higher amount of martensite is transformed during martensite transformation, so the alloy exhibits a higher amount of energy dissipation due to higher hysteresis.…”

Novel Research for Development of Shape Memory Alloys

“…Wu et al investigated damping characteristics of inherent and intrinsic internal friction of Cu-Zn-Al Shape Memory Alloys[31]. The Cu-xZn-11Al SMAs are promising for practical high-damping applications under isothermal conditions because they possess good workability, low cost, acceptable mechanical properties, and the high damping capacities.Adachi et al made the phase diagram of Ni 2 MnGa 1-x Fe x on the basis of the experimental results [32].…”