Effects of femtosecond laser shock peening in distilled water on the surface characterizations of NiTi shape memory alloy

Wang, Hao; Pöhl, Fabian; Yan, Kai; Decker, Peer; Gurevich, Evgeny L.; Ostendorf, Andreas

doi:10.1016/j.apsusc.2018.12.087

Cited by 34 publications

(8 citation statements)

References 23 publications

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“…The difference is the shallow depth of cracks originating from the LIPSS and the growth seeds generated by fs-LA. Fs-LA can greatly refine the grains in the substrate into nanoscale structures, 59 so the grown crystals become highly uniform after annealing at 600 °C for 2 h. Due to the lack of deposited NPs to create a large region of macropores, the density of macropores grown from the fs-5W-W sample is very limited, and only separated macropores can be found. Overall, it can be concluded that the LIPSS provides a better template for the nucleation and growth of smaller and more homogeneous particles than pure W plates and facilitates the formation of hierarchical nanostructures at 600/800 °C and hierarchical macroporous structures at 1000 °C while deposited by a high density of NPs.…”

Section: Resultsmentioning

confidence: 99%

Hierarchical WO_3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Zhang

Liu

et al. 2022

ACS Appl. Mater. Interfaces

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Oxygen-vacancy-rich WO3–x absorbers are gaining increasing attention because of their extensive absorbance-based applications in near-infrared shielding, photocatalysis, sterilization, interfacial evaporator and electrochromic, photochromic, and photothermal fields. Thermal treatment in an oxygen-deficient atmosphere enables us to prepare WO3–x but lacks the capacity for finely manipulating the grown structures. In this work, we present that laser-induced periodic surface structure (LIPSS) obtained by femtosecond laser ablation is a good template to grow various hierarchical WO3–x ultrabroadband absorbers and photothermal converters by thermal oxidation annealing in air. Increasing annealing temperature from 600 to 1000 °C allows the manipulation of WO3–x crystal sizes from ∼70 nm to ∼4 μm, accompanied by a color transition from brown to dark blue and finally to yellow. Benefiting from annealing-induced surface cracks and phase transition into WO3–x (containing both WO3 and W18O49) at 600 °C, excellent UV–vis–NIR–MIR ultrabroadband absorbers were produced: >90% UV–NIR absorbance (0.3–2.5 μm) and 50–90% MIR absorbance (2.5–16 μm), much better than most W-based metamaterial absorbers. The higher the annealing temperature (1000 > 800 > 600 °C), the better the photothermal performances (sample temperature as the indicator) of annealed interfaces due to the increased oxidation rates and resultant thicker oxide layers (6, 150, and 507 μm), a trend which is more apparent upon the irradiation of high-density (3160 mW/cm2) and ultrabroadband (200–2500 nm) light but much less apparent for shorter-band (200–800, 420–800, 800–2500 nm, etc.) and less-intensity (1694, 1540, 1460 mW/cm2, etc.) light irradiation. This phenomenon indicates that (1) higher-performance ultrabroadband absorbers possess a higher photothermal conversion capacity; (2) thicker-WO3–x oxide layer converters are more effective in preserving photothermal heat; and (3) both the W-LIPSS and metal tungsten substrate can quickly dissipate the photothermal heat to inhibit heat accumulation in the oxide photothermal converters. It is also proved that ablation-induced high-pressure shockwaves can produce deformation layers in the subsurfaces to release annealing-induced stresses, beneficial for the formation of less-cracked non-stoichiometric WO3–x interfaces upon annealing. High-pressure shockwaves are also capable of inducing grain refinement of LIPSS, which facilitates a homogeneous growth of small non-stoichiometric metal-oxide crystals upon annealing. Our results indicate that femtosecond laser ablation is a convenient upstream template-fabrication technique compatible with the thermal oxidation annealing method to develop advanced functional oxygen-vacancy metal-oxide interfaces.

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Section: Resultsmentioning

confidence: 99%

Hierarchical WO_3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Zhang

Liu

et al. 2022

ACS Appl. Mater. Interfaces

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“…Thus, similar improvement of surface mechanical properties can be achieved with lower energy input, compared with NLSP, such as surface hardness [26,28], anti-corrosion properties [9,23], anti-fatigue properties [22,29]. Moreover, surface textures and ripples are formed on those peened surfaces to obtain the multifunctional surfaces, which is a unique characteristic of FLSP [25]. The adding effects of multi-cycles NLSP on the affected depths usually reach saturated values within 3-5 impacts [30].…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, femtosecond laser shock peening (FLSP) can be conducted directly under air conditions, which provides different engineering potentials [22][23][24]. In FLSP processing, milli-Joule-scale energy input (even micro-Joule-scale energy input [25,26]) is adopted, which is three orders of magnitude lower than that used in NLSP [20,22,23]. Due to the ultra-short duration characteristics, FLSP induces high shock wave pressure of several hundred GPa in the air with milli-Joule-scale energy [25,26], whereas 1-10 GPa pressure can be induced in NLSP with Joule-scale energy [13,14,20].…”

Section: Introductionmentioning

confidence: 99%

“…In FLSP processing, milli-Joule-scale energy input (even micro-Joule-scale energy input [25,26]) is adopted, which is three orders of magnitude lower than that used in NLSP [20,22,23]. Due to the ultra-short duration characteristics, FLSP induces high shock wave pressure of several hundred GPa in the air with milli-Joule-scale energy [25,26], whereas 1-10 GPa pressure can be induced in NLSP with Joule-scale energy [13,14,20]. The introduction of water layers weakens the peening effects as strong ionization of confining medium shields the majority absorption of incident laser energy [20].…”

Section: Introductionmentioning

confidence: 99%

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Laser Shock Peening of Ti6Al4V Alloy with Combined Nanosecond and Femtosecond Laser Pulses

Sun¹,

Bai

et al. 2021

Metals

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Laser shock peening (LSP) with nanosecond or femtosecond laser pulses is applied to improve the mechanical properties of metallic materials. Thus, it is necessary to compare the effects of different processing methods on microstructure changes and property improvement. In this study, nanosecond LSP (NLSP), femtosecond LSP (FLSP), and LSP with combined nanosecond and femtosecond laser pulses (F-NLSP) are conducted on Ti6Al4V alloys to compare the surface morphologies, in-depth microstructures, and nanohardness changes. In FLSP, the peened surface is smooth, and the affected depth is limited near the peened surface. NLSPed and F-NLSPed samples present rough surfaces due to the severe ablation process. Small equiaxed grains with no preferred grain orientation are denser in F-NLSPed samples than that in NLSPed samples. Compared with NLSPed samples, the affected depth and amplitude of in-depth nanohardness are larger in F-NLSPed samples. This is attributed to the increased laser absorption of incident laser on the treated surface by femtosecond laser pulses. The results in this study show the effects of different LSP methods and provide chances in engineering potentials for material property improvements.

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“…In detail, SLM often requires the adoption of post-processing treatments, not only for inducing tailored microstructures through heat treatments but also surface modifications [19,20], due to high roughness values and relevant dimensional errors [21,22]. The literature reports some works regarding the performances of conventional treatments, like electropolishing [23,24], and advanced finishing post-processing, like laser shock peening [25,26] and ultrasonic nanocrystal surface modification (UNSM) [27,28,29], on NiTinol samples. The main achievements obtained during the surface modification processing were good surface roughness values and improved surface responses, such as wear resistance, fatigue behavior, and biological response.…”

Section: Introductionmentioning

confidence: 99%

Effect of Ultrasonic Nanocrystal Surface Modification on the Microstructure and Martensitic Transformation of Selective Laser Melted Nitinol

et al. 2019

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Nitinol has significant potential for biomedical and actuating-sensing devices, thanks to its functional properties. The use of selective laser melting (SLM) with Nitinol powder can promote novel applications aimed to produce 3D complex parts with integrated functional performances. As the final step of the production route, finishing processing needs to be investigated both for the optimization of the surface morphology and the limit alteration of the Nitinol functional properties. In this work, the effect of an advanced method of surface modification, ultrasonic nanocrystal surface modification (UNSM), on the martensitic transformation and microstructure of SLM built Ni50.8Ti49.2 (at.%) was investigated. Scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry indicated that the UNSM process can generate stress-induced martensite, at least partially suppressing the martensitic transformation. The microhardness profile indicates that the UNSM process can affect the mechanical properties of the SLMed Nitinol sample in a range of up to approximately 750 μm in depth from the upper surface, while electron backscatter diffraction analysis highlighted that the initial austenitic phase was modified within a depth below 200 μm from the UNSMed surface.

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Effects of femtosecond laser shock peening in distilled water on the surface characterizations of NiTi shape memory alloy

Cited by 34 publications

References 23 publications

Hierarchical WO_3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Hierarchical WO_3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Laser Shock Peening of Ti6Al4V Alloy with Combined Nanosecond and Femtosecond Laser Pulses

Effect of Ultrasonic Nanocrystal Surface Modification on the Microstructure and Martensitic Transformation of Selective Laser Melted Nitinol

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Effects of femtosecond laser shock peening in distilled water on the surface characterizations of NiTi shape memory alloy

Cited by 34 publications

References 23 publications

Hierarchical WO3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Hierarchical WO3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Laser Shock Peening of Ti6Al4V Alloy with Combined Nanosecond and Femtosecond Laser Pulses

Effect of Ultrasonic Nanocrystal Surface Modification on the Microstructure and Martensitic Transformation of Selective Laser Melted Nitinol

Contact Info

Product

Resources

About

Hierarchical WO_3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures

Hierarchical WO_3–x Ultrabroadband Absorbers and Photothermal Converters Grown from Femtosecond Laser-Induced Periodic Surface Structures