Effect of Mo on the Microstructure and Superelasticity of Ti-Ni-Cu Shape Memory Alloys

Zhao, Guangwei; Chen, Jian; Fang, Dong; Ye, Yongsheng; Huang, Caihua; Ye, Xicong

doi:10.1007/s11665-020-05348-x

Cited by 6 publications

(2 citation statements)

References 29 publications

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“…Moreover, adding more Zr to NiTi SMAs can reduce processability and increase brittleness, as mentioned in [30], which is consistent with our findings. During compression tests, the compression energy results from the processes of austenite elastic deformation, stress-induced martensite transformation, and comprehensive deformation of martensite [49,50]. Differences in these three deformation conditions between as-cast and as-homogenized states can affect the mechanical properties.…”

Section: Discussionmentioning

confidence: 99%

Effect of Homogenization on the Transformation Temperatures and Mechanical Properties of Cu15Ni35Hf12.5Ti25Zr12.5 and Cu15Ni35Hf15Ti20Zr15 High-Entropy Shape Memory Alloys

et al. 2023

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The major challenge of high-temperature shape memory alloys (SMAs) is the collocation of phase transition temperatures (TTs: Ms, Mf, As, Af) with the mechanical properties required for application. Previous research has shown that the addition of Hf and Zr into NiTi shape memory alloys (SMAs) increases TTs. Modulating the ratio of Hf and Zr can control the phase transformation temperature, and applying thermal treatments can also achieve the same goal. However, the influence of thermal treatments and precipitates on mechanical properties has not been widely discussed in previous studies. In this study, we prepared two different kinds of shape memory alloys and analyzed their phase transformation temperatures after homogenization. Homogenization successfully eliminated dendrites and inter-dendrites in the as-cast states, resulting in a reduction in the phase transformation temperatures. XRD patterns indicated the presence of B2 peaks in the as-homogenized states, demonstrating a decrease in phase transformation temperatures. Mechanical properties, such as elongation and hardness, were improved due to the uniform microstructures achieved after homogenization. Moreover, we discovered that different additions of Hf and Zr resulted in distinct properties. Alloys with lower Hf and Zr had lower phase transformation temperatures, followed by higher fracture stress and elongation.

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Section: Discussionmentioning

confidence: 99%

Effect of Homogenization on the Transformation Temperatures and Mechanical Properties of Cu15Ni35Hf12.5Ti25Zr12.5 and Cu15Ni35Hf15Ti20Zr15 High-Entropy Shape Memory Alloys

et al. 2023

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“…The E consumed was directly related to the irreversible strain, which increased gradually for all samples with an increase in the number of cycles (figures 12(g)-(i)). The continuous accumulation of residual strain can be attributed to the progressive increase in the amount of residual martensite generated upon unloading [59], which is due to the obstruction of the reverse transformation of martensite to austenite caused by high-density dislocations [59,60]. The reorientation or detwinning of the self-adapted martensite in the samples resulted in the maximum ∆ε occurring in the first cycle.…”

Section: Mechanical Properties and Shape Memory Functionmentioning

confidence: 99%

Design and additive manufacturing of bionic hybrid structure inspired by cuttlebone to achieve superior mechanical properties and shape memory function

Yuan,

Gu,

Liu

et al. 2024

Int. J. Extrem. Manuf.

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Lightweight porous materials with high load-bearing, damage tolerance and energy absorption as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications, e.g., aerospace, automobiles, electronics, etc. Cuttlebone produced in the cuttlefish has evolved vertical walls with the optimal corrugation gradient, enabling stress homogenization, significant load bearing, and damage tolerance to protect the organism from high external pressures in the deep sea. This work illustrated that the complex hybrid wave shape in cuttlebone walls, becoming more tortuous from bottom to top, creates a lightweight, load-bearing structure with progressive failure. By mimicking the cuttlebone, a novel bionic hybrid structure (BHS) was proposed, and as a comparison, a regular corrugated structure (RCS) and a straight wall structure (SWS) were designed. Three types of designed structures have been successfully manufactured by laser powder bed fusion with NiTi powder. The LPBF-processed BHS exhibited a total porosity of 0.042% and a good dimensional accuracy with a peak deviation of 17.4 μm. Microstructural analysis indicated that the LPBF-processed BHS had a strong (001) crystallographic orientation and an average size of 9.85 μm. Mechanical analysis revealed the LPBF-processed BHS could withstand over 25 000 times its weight without significant deformation and had the highest specific energy absorption value (5.32 J/g) due to the absence of stress concentration and progressive wall failure during compression. Cyclic compression testing showed that LPBF-processed BHS possessed superior viscoelastic and elasticity energy dissipation capacity. Importantly, the uniform reversible phase transition from martensite to austenite in the walls enables the structure to largely recover its pre-deformation shape when heated (over 99% recovery rate). These design strategies can serve as valuable references for the development of intelligent components that possess high mechanical efficiency and shape memory capabilities.

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As-Cast High Entropy Shape Memory Alloys of (TiHfX)50(NiCu)50 with Large Recoverable Strain and Good Mechanical Properties

Zhao

et al. 2022

J. of Materi Eng and Perform

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Effect of Mo on the Microstructure and Superelasticity of Ti-Ni-Cu Shape Memory Alloys

Cited by 6 publications

References 29 publications

Effect of Homogenization on the Transformation Temperatures and Mechanical Properties of Cu15Ni35Hf12.5Ti25Zr12.5 and Cu15Ni35Hf15Ti20Zr15 High-Entropy Shape Memory Alloys

Effect of Homogenization on the Transformation Temperatures and Mechanical Properties of Cu15Ni35Hf12.5Ti25Zr12.5 and Cu15Ni35Hf15Ti20Zr15 High-Entropy Shape Memory Alloys

Design and additive manufacturing of bionic hybrid structure inspired by cuttlebone to achieve superior mechanical properties and shape memory function

As-Cast High Entropy Shape Memory Alloys of (TiHfX)50(NiCu)50 with Large Recoverable Strain and Good Mechanical Properties

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