Table 1 - available via license: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Content may be subject to copyright.
Source publication
Laser shock peening (LSP) is a surface treatment process for increasing the strength and reliability of metal components. Traditionally applied to composite structures of automotive and medical applications, the LSP technology also shows great potential for aircraft parts to improve the fatigue resistance of highly stressed critical aircraft turbin...
Citations
... In addition, it makes use of chemical substances and extracts from plants [3]. One of the most excellent techniques to create materials in their nanoscale is by laser ablation in liquid media [3][4][5]. Nowadays, high-purity nanosized particles are created using the simple and environmentally friendly laser pulse ablation process [2]. The process of laser ablation, which produces metallic nanoparticles and is characterized by superb purity, produces these particles [2]. ...
Chitosan was encapsulated by TiO2 and Fe2O3 nanoparticles using laser ablation route. The synthesized films have different nanoparticles concentration depending on the ablation time. The films have been studied using XRD, FTIR, TGA, TEM, UV, and AC measurements. The TGA results show that the most stable film was pure CS, and the lowest thermally stable film was the film of 10 min ablation. Further, the TEM showed that the particle size varied from 125 to 137 nm. Moreover, the direct band gap, indirect band gap, and refractive index were studied optically. The direct band gap decreased from 5.72 to 3.55 eV by raising the content of the doping. Further, the refractive index increased from 2.04 to 2.95. The indirect band gap has been calculated optically and obtained a decrease in band gap from 4.76 to 1.57 eV. Chitosan/TiO2/Fe2O3 nanoparticles have good optical characteristics, which might be used in the creation of new optoelectronics devices. The objective of this study is to improve the characteristics of CS polymer by incorporating metal nanoparticles, namely TiO2 and Fe2O3, into the matrix using a laser ablation approach. This is done with the aim of enhancing the performance of the polymer for optoelectronics applications.
... SPD occurs near the surface of the material when the original sample is very smooth, indicating that LSP can greatly increase surface roughness. Generally, lower surface roughness results in lower COF and wear rate [67]. However, LSP treatment has been observed to clearly reduce the COFs and wear rates of conventional metallic materials, additively manufactured materials, and coated materials (Figures 9, 10, 12, and 13). ...
With the rapid development of the advanced manufacturing industry, equipment requirements are becoming increasingly stringent. Since metallic materials often present failure problems resulting from wear due to extreme service conditions, researchers have developed various methods to improve their properties. Laser shock peening (LSP) is a highly efficacious mechanical surface modification technique utilized to enhance the microstructure of the near-surface layer of metallic materials, which improves mechanical properties such as wear resistance and solves failure problems. In this work, we summarize the fundamental principles of LSP and laser-induced plasma shock waves, along with the development of this technique. In addition, exemplary cases of LSP treatment used for wear resistance improvement in metallic materials of various nature, including conventional metallic materials, laser additively manufactured parts, and laser cladding coatings, are outlined in detail. We further discuss the mechanism by which the microhardness enhancement, grain refinement, and beneficial residual stress are imparted to metallic materials by using LSP treatment, resulting in a significant improvement in wear resistance. This work serves as an important reference for researchers to further explore the fundamentals and the metallic material wear resistance enhancement mechanism of LSP.
... Especially for high-end parts with high requirements regarding the surface integrity (aircraft and aerospace), the application of LSP seems to be more beneficial than conventional SP [5]. Multiple investigations have shown the beneficial effect of LSP on typical Ti-, Al-, Fe-, and Ni-alloys like Ti-6AL-4V [6], EN-AW 2024 [7], EN-AW 7075 [8], [9], 15-5 PH [3], and Inconel 718 [10]. However, compared to SP, investments and production costs (process time) are much higher for the application of LSP. ...
Laser shock peening (LSP) is a mechanical surface treatment process to modify near-surface material properties. Compared to conventional shot peening (SP) the process parameters can be finely adjusted with greater precision and a higher penetration depth of compressive residual stresses could be reached. However, high process times of LSP leads to high production costs. In this study, ultrafast LSP (U-LSP) with an ultrafast laser source (pulse time in the picosecond range) was applied on specimens made of X5CrNiCu15-5 and AlZnMgCu1.5. The surface characteristics (surface roughness) and surface-near properties (microstructure, residual stresses, and phase composition) were compared to the as-delivered condition, to conventional laser shock peening (C-LSP), and to SP, whereas metallographic analyses and X-ray and synchrotron radiation techniques were used. The process time was significantly lower via U-LSP compared to C-LSP. For X5CrNiCu15-5, no significant compressive residual stresses were induced via U-LSP. However, for AlZnMgCu1.5, similar compressive residual stresses were reached via C-LSP and U-LSP; however, with a lower penetration depth. A change in the phase portions in the surface layer of X5CrNiCu15-5 after C-LSP compared to SP were determined.
... Aluminium alloys such as 2000, 6000 and 7000 series showed an improvement in hardness due to laser peening [113,116,117]. For example, AA2024 showed an increase in hardness from 150 HV (Untreated) to 175 HV0.1 after the LSP process [118]. ...
... For example, AA2024 showed an increase in hardness from 150 HV (Untreated) to 175 HV0.1 after the LSP process [118]. Similarly, Al7075 alloy treated by Mostafa et al. [113] showed an increase in hardness to 160 HV compared to the unpeened samples (80 HV), and the effect of work hardening depth extends to 175 µm. Sathyajith et al. [117] peened Al6061-T6 and observed the enhancement of hardness (61 HV) compared to unpeened samples (50-52 HV); the effect continues for more than a depth of 1400 µm. ...
Laser shock peening (LSP) is a unique and efficient surface modification technique that surface engineers have commonly adopted to tailor metallic materials’ surface and subsurface properties. The primary goal of this review paper is to highlight LSP as a surface modification technique for materials used in aeroengine, as this further ameliorates the commercialization of LSP in aeroengine sectors. The recent research articles focused on the application of LSP to improve the surface characteristics (i.e. surface residual stresses, hardness) and to resist the corresponding service challenges (i.e. fatigue, wear) of the aeroengine metallic material have been reviewed. In addition, a brief explanation of LSP and its controlling parameters is included. From the aeroengines perspective, challenges and future aspects for improving LSP application and commercialization are summarised based on the authors’ experience and published literature.
... In addition, hardness enhancement was reported in different environments; Al-alloys hardness in the air [12,23,24] and zinc in air and ethanol [25]. Furthermore, the effects of laser hardening technology on microstructure, hardness, and tensile test of LPBF medium manganese steel produced by laser powder bed fusion were reported and evaluated by Radkiewicz et al [26]. ...
... The maximum microhardness value for Al irradiated by a 30 mJ/ pulse was 36.7 HV at 1.5 bar, which increased by a factor of 3.40 compared with the untreated, approximately close to factor of 4 reported in ref. [18], as illustrated in Fig. 10(a). This may have been caused by the cone shape with a periodic surface structures (ripples) and the number of holes, as reported by [16,23,25]. Furthermore, when irradiated energy was increased to 60 mJ/pulse, the maximum microhardness value was 39.3 HV at 1.5 bar; this may have been due to the pores and flake-like structure shown in the inset of Fig. 4(e) that covered the irradiation surface and the XRD pattern shifted from (0 0 2) to (0 2 2) shown in Fig. 8(b), as illustrated in Fig. 10(b). ...
This study investigates the surface modification of a material irradiated by a nanosecond Nd:YAG green laser while exposed to a gas flow. Scanning electron microscopy images and X-ray diffraction profiles illustrate the effect of laser irradiation in different environments, especially under backing gas pressures of 0.5, 1, and 1.5 bar applied through a supersonic nozzle. After irradiation, the microhardness obtained through the Vickers hardness increased by a factor of 3.40 and 4.90 for Al and Ag, respectively. This enhancement can be attributed to the surface and structural modification of the irradiated sample under different environments. Furthermore, the microhardness was found to be associated with the microstrain.
... It was observed that no eddy currents or hot gas jets are associated with the known beam area, and no rays spill out. The applied energy can be accurately directed where needed on the surface; thus, it is described as an actual surface [9][10][11]. Laser shock peening (LSP) is a technique utilized to change the properties of the metal surface by increasing roughness, hardness, power, and reliability to the material's presence of compressive residual stresses [12,13]. ...
... Each labeled peak in the graph shows a functional group. Various peaks identified at wavenumbers of 712 cm −1 , 765 cm −1 , 857 cm −1 , 925 cm −1 , 1120 cm −1 , 1188 cm −1 , 1390 cm −1 indicate the presence of CdO [70]. Adnan et al. [9] also claimed that the peaks appearing in the range of 1386 to 1400 cm −1 belong to CdCO3 that is also confirmed from XRD results. ...
... Various peaks identified at wavenumbers of 716.18 cm −1 , 851.02 cm −1 , 1120.4 cm −1 , 1397.95 cm −1 , and 1456.92 cm −1 , indicate the presence of CdO [70]. The peaks appearing in the range of 1386 to 1400 cm −1 belong to CdCO3 formation, whereas additionally identified peaks at higher wavenumbers of 1593.3 cm −1 , 1692 cm −1 , 1745 cm −1 , 1994 cm −1 ,2121 cm −1 and 2331 cm −1 , correspond to Cd-OH, C-C, Carbonyle (C=O), Hydrides of metal (Cd-H) and Carbonyle (C=O) [76,77]. ...
In the present study KrF Excimer laser has been employed to irradiate the Cadmium (Cd) targets for various number of laser pulses of 500, 1000, 1500 and 2000, at constant fluence of 3.6 J cm−2. Scanning Electron Microscopy (SEM) analysis was utilized to reveal the formation of laser induced nano/micro structures on the irradiated target (Cd) surfaces. SEM results show the generation of cavities, cracks, micro/nano wires/rods, wrinkles along with re-deposited particles during irradiation in air, whereas subsurface boiling, pores, cavities and Laser Induced Periodic Surface Structures (LIPSS) on the inner walls of cavities are revealed at the central ablated area after irradiation in propanol. The ablated volume and depth of ablated region on irradiated Cd targets are evaluated for various number of pulses and is higher in air as compared to propanol ambient. Fast Fourier Transform Infrared spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) analyses show the presence of oxides and hydro-oxides of Cd after irradiation in propanol, whereas the existence of oxides is observed after irradiation in air ambient. Nano-hardness tester was used to investigate mechanical modifications of ablated Cd. It reveals an increase in hardness after irradiation which is more pronounced in propanol as compared to air.
... Cemented tungsten carbides remain in the liquid state at temperatures > 3000 K [25]. A strong pulsed laser fluence induces tensile stress [24,[26][27][28]. The induced tensile stress pushed away the melted tungsten carbide. ...
Enhanced cutting tool blades are required to manufacture next-generation small multilayer ceramic capacitors. Cemented tungsten carbide is used as the material for these blades. Recently, laser ablation has been used to fabricate sharp fine blades. In this study, a femtosecond laser was used to precisely and finely machine cemented tungsten carbide. Furthermore, we analyzed the interaction between the femtosecond laser and cemented tungsten carbides depending on the laser fluence. Scanning electron microscopy, confocal laser scanning microscopy, and a two-temperature model were used for the analysis. Based on this analysis, we understood the formation of burrs, nanoparticles, and droplets induced by a femtosecond laser. A laser beam with a diameter of ~ 16 µm was used for irradiation. Moreover, beams with fluence values of 0.24, 1.13, 2.12, and 3.40 J/cm2 were irradiated on the surface of cemented tungsten carbides. The total fluence was the same as that of the absorbed surface. Although the total fluence was the same, burrs, nanoparticles, and droplets were generated at higher fluences. Owing to the higher fluence, the temperature increased, thus increasing the time required to achieve thermal equilibrium between the electron and the lattice. Consequently, we propose the formation process for burrs, nanoparticles, and droplets. In addition, we demonstrate a machining solution without burrs, nanoparticles, or droplets. These results will prove useful across a number of different industries.
... Oblique laser shock peening (OLSP) is a surface treatment process to improve the strength and reliability of metal parts [2][3][4], which can significantly improve mechanical properties and prolong the service life of materials by utilizing the force effect of a pulsed laser beam [5,6]. At present, it has become a new and effective means for strengthening the surface of the turbine disk. ...
As a metal surface strengthening technology, oblique laser shock peening uses the force effect of pulsed laser beams to significantly improve the mechanical properties of materials and prolong service life. However, the processing of metal parts still requires a high cost for testing the quality of the finished product. At present, there is no systematic and complete measurement method or evaluation system for the finished products of oblique laser shock peening technology. In this paper, a principal component analysis method and a comprehensive index method are organically combined to construct a method for evaluating the effect of oblique laser shock peening of FGH95 superalloy turbine disks. We measured 10 real data of FGH95 superalloy specimens after oblique laser shock peening by using the orthogonal test method and verified the data. Based on the evaluation results, we put forward a series of suggestions to improve the quality of oblique laser shock peening of FGH95 high-temperature turbine disks, providing a certain reference and guidance for processing FGH95 superalloy turbine disks.
... Laser shock peening, shot peening, and deep rolling have been used to improve the fretting fatigue, strength, and hardness of Al7075 alloy [24,25]. These structural and mechanical changes are particularly challenging to understand during shock, impact, and ballistic loading, yet this is critical for the use of Al7075 in armor, munitions, and military aircraft [26,27]. ...
Precipitate-matrix interactions govern the mechanical behavior of precipitate strengthened Al-based alloys. These alloys find a wide range of applications ranging from aerospace to automobile and naval industries due to their low cost and high strength to weight ratio. Structures made from Al-based alloys undergo complex loading conditions such as high strain rate impact, which involves high pressures. Here we use diamond anvil cells to study the behavior of Al-based Al7075 alloy under quasi-hydrostatic and non-hydrostatic pressure up to ~53 GPa. In situ X-ray diffraction (XRD) and pre- and post-compression transmission electron microscopy (TEM) imaging are used to analyze microstructural changes and estimate high pressure strength. We find a bulk modulus of 75.2 +- 1.9 GPa using quasi-hydrostatic pressure XRD measurements. XRD showed that non-hydrostatic pressure leads to a significant increase in defect density and peak broadening with pressure cycling. XRD mapping under non-hydrostatic pressure revealed that the region with the highest local pressure had the greatest increase in defect nucleation, whereas the region with the largest local pressure gradient underwent texturing and had larger grains. TEM analysis showed that pressure cycling led to the nucleation and growth of many precipitates. The significant increase in defect and precipitate density leads to an increase in strength for Al7075 alloy at high pressures.
