PSI - Issue 69

Diego Scaccabarozzi et al. / Procedia Structural Integrity 69 (2025) 80–88

87

Sample 1 5355.9 0.03

2.56

3.6 5302.1 0.13

5.56

11

5311.2 0.12

5.30

9.7

Sample 2 5624.3 0.02

2.44

5.8 5381.9 0.10

6.71

7.2

5395.8 0.05

6.07

0.77

Sample 3 5525.8 0.01

2.61

7.0 5291.8 0.11

7.07

3.2

5288.1 0.05

7.35

9.3

0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009

Loss factor (ζ)

1

2

3

Samples

Before Treatment

A8er (T500-5’)

A8er (T500-10’)

Fig. 6. Trend of loss factor vs heat treatment. 1σ bands are visible.

The first heat treatment (T500-5’) significantly enhanced the damping capacity across all samples. The loss factor increased to values ranging from 0.6% to 0.7%. This increase indicates that thermal treatment improves internal friction and energy dissipation mechanisms. Concurrently, the natural frequencies decreased, which aligns with the expected microstructural softening reported in the literature. Following the second heat treatment (T500-10’), the loss factors stabilised with minimal further changes compared to the (T500-5’) condition, suggesting that the microstructural modifications introduced by the second treatment were incremental. This consolidates the major role of the initial heat treatment. Moreover, the natural frequencies remained relatively constant, which indicates no substantial alterations in the material stiffness. 4. Conclusion The study demonstrates the effect of heat treatments to optimise the damping characteristics of LPBFed Nitonol components. The results showed that the heat treatment effectively enhances the damping performance up to three times with respect to the as-built condition. These findings are pivotal for developing lightweight, vibration-resistant structures in aerospace engineering, suggesting avenues for further research to refine heat treatment techniques for maximum performance consistency and efficiency. In fact, additional improvement of the damping capacity is expected in the case that AMed structures would undergo larger deformation, as expected in the vibrational environment of space payloads and structures. References [Biffi, 2019] C.A. Biffi, A. Tuissi, Laser shape setting of superelastic NiTi wire: effects of laser beam power and axial pre-load, 2019 Smart Materials and Structures. https://doi.org/10.1088/1361-665X/ab1e86.