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AIP Conference Proceedings [AIP Publishing XLIII ACADEMIC SPACE CONFERENCE: dedicated to the memory of academician S.P. Korolev and other outstanding Russian scientists – Pioneers of space exploration - Moscow, Russia (28 January–1 February 2019)] XLIII ACADEMIC SPACE CONFERENCE: dedicated to the memory of academician S.P. Korolev and other outstanding Russian scientists – Pioneers of space exploration - Laser shock peening with low-energy laser sources: Techniques and prospects
摘要： The first part of the article considers practical prospect of using laser shock peening technology. There are presented prerequisites of solving several technological tasks related to local impact with laser shock processing. The second part of the article is devoted to analysis and parameter optimization that permit to apply low-energy sources for laser shock processing. The influence of various absorbing and tamping coatings used in the process of laser shock peening on the properties of the processed material was researched. Physical and technological properties of viewed coatings were evaluated. The results were evaluated by the treated material microhardness, due to its linear relationship with the stresses in material. Conducted research enables the selection of the optimal environments combination to achieve the most effective results in the process of laser shock peening.
关键词： laser shock peening,surface modification,low-energy laser sources,tamping coatings,absorbing coatings,microhardness
更新于2025-09-12 10:27:22
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Effective femtosecond laser shock peening on a Mg–3Gd alloy at low pulse energy 430?μJ of 1?kHz
摘要： In this paper, microstructure evolution and hardness of Mg-3Gd alloy treated by femtosecond (fs) laser shock peening (LSP) with direct and con?ned ablation modes were investigated in detail. Under a relatively low pulse energy of 430 μJ with a repetition of 1 kHz, the surface hardness of sample has been enhanced by 70% effectively. Compared with ns-LSP with pulse ?uence of 71.7 J/cm 2 , fs-LSP with pulse ?uence of 34.2 J/cm 2 is superior in the hardness increment, both of which are in the same order of magnitude. A distinct grain re?nement of surface layer has been discovered and results in the increase of hardness. Nonuse of absorption and con?ning layers and the employment of the industry commercial fs laser with high repetition can inspire big potential LSP application in special metal material.
关键词： Mg–3Gd alloy hardness,Laser shock peening,Surface treatment,Femtosecond laser
更新于2025-09-12 10:27:22
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Surface modification methods for fatigue properties improvement of laser-beam-welded Ti-6Al-4V butt joints
摘要： Surface and internal defects formed upon laser beam welding (LBW) have been recognized as a serious problem because they cause stress concentration leading to premature failure of a welded component. This paper seeks to remedy these weld imperfections by applying various post-weld treatments and analyzing their effect on the high cycle fatigue (HCF) performance of welded joints. High efficiency of laser-based post-processing techniques after welding such as laser surface remelting (LSR) and laser shock peening (LSP) was demonstrated and compared with conventional approaches. The study reveals that welding porosity determines the internal crack initiation of the surface-treated weldments. Influence of process parameters on porosity level and the HCF properties is presented in detail. Based on an extensive experimental study, practical guidelines needed to mitigate the notch effect from defects and to maximize the fatigue performance of the laser-welded Ti-6Al-4V butt joints are given.
关键词： laser shock peening,Laser beam welding,high cycle fatigue,porosity,defects
更新于2025-09-12 10:27:22
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Influence of multiple laser impacts on thin leading edges of turbine blade
摘要： Laser shock peening is a mechanical surface improvement treatment used to enhance the fatigue life of critical components. This paper investigates the influence of multiple square laser impacts to study their special effect on the diverse mechanical behaviours of the thin leading edge surface of turbine blades. Most works existing in the literature have presented experimental investigations. The originality of our paper is to validate and numerically simulate the proposed model. Indeed, a 3D finite element method of a thin leading edge specimen, Ti–6Al–4V, of a turbine blade is numerically simulated using the ABAQUS software. The mechanical surface modifications (residual stresses, equivalent plastic strains and Johnson–Cook superficial damage) induced by the multiple square laser impact are examined in detail. The main purpose of this investigation is to determine the effects of single-sided and double-sided laser shock peening.
关键词： turbine blade,thin leading edge,Ti–6Al–4V,multiple square laser impacts,finite element method,equivalent plastic strain,Laser shock peening,Johnson–Cook superficial damage,compressive residual stress
更新于2025-09-12 10:27:22
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Improving impact wear resistance of Ti-6Al-4V alloy treated by laser shock peening
摘要： The effects of laser shock peening (LSP) on the impact wear behavior of Ti?6Al?4V alloys were investigated by a homemade impact wear test rig. The microstructure and mechanical properties of the peened samples were studied. During the impact wear test, the energy absorption, impact force, wear contact time and wear mechanism of all the test samples were investigated in terms of the influence of the impact kinetic energy. The results showed that microhardness, elastic modulus and residual compressive stress of the treated samples were markedly improved. The wear resistances of both treated samples were highly improved after LSP, and a higher pulse energy corresponded to a more obvious effect. Besides, the wear in all test samples involved a combination of abrasive and oxidation wear and fatigue spalling.
关键词： laser shock peening,wear mechanism,impact wear,impact kinetic energy,Ti?6Al?4V alloy
更新于2025-09-12 10:27:22
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Multi-Objective Optimization of Residual Stress and Cost in Laser Shock Peening Process Using Finite Element Analysis and PSO Algorithm
摘要： Laser shock peening (LSP) is an effective process utilized for surface enhancement of metal parts so that generating compressive residual stresses (RS) on the surface improves fatigue life of the material. The main affecting parameters on surface negative residual stress are laser power, laser beam size and shape, peening pitch and pattern. Varying these parameters alters the magnitude and depth of RS as well as the cost of LSP. An integrated method for simulation of optimum LSP process is presented in this paper, in which Particle Swarm Optimization (PSO) technique was employed utilizing Python coding in ABAQUS finite element environment to maximize the uniformity of compressive RS and minimize LSP cost on an Inconel 718 super-alloy specimen. The mentioned affecting parameters were selected as optimization parameters, and minimum acceptable amounts and depth of compressive RSs were two main design constraints. Simulation results were compared with previously published experimental ones, and optimum LSP variables were finally determined and presented for certain amount of design constraints. It was revealed that, relatively small circular laser beam, shot by square scanning pattern, leads to generate the most uniform RS with minimum LSP cost.
关键词： Particle swarm multi-objective optimization,Laser shock peening,Residual stress,Python coding,Finite element simulation
更新于2025-09-12 10:27:22
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Pore Closure Effect of Laser Shock Peening of Additively Manufactured AlSi10Mg
摘要： This article reports on an exceptional insight provided by nondestructive X-ray tomography of the same samples before and after laser shock peening (LSP). The porosity in two additively manufactured aluminum alloy (AlSi10Mg) tensile samples before and after LSP was imaged using identical X-ray tomography settings and overlap of the data was performed for direct comparison. The results indicate clearly that near-surface pores are closed by the process, while internal pores remain unaffected. LSP has become well known as a method to improve the fatigue properties of materials, including those of additively manufactured aluminum alloys. This improvement is usually attributed to the compressive residual stress induced by the process. The additional effect of closure of near-surface pores that is illustrated in this work is of interest for additive manufacturing because additive manufacturing is not yet able to produce completely pore-free components. Since the critical pore initiating fatigue cracks are always attributed to surface or subsurface pores, the closure of these pores may play an additional role in improving the fatigue properties. While more work remains to unravel the relative importance of near-surface porosity compared to the compressive residual stress effect, this work clearly shows the effect of LSP—closing of pores near the surface. For the processing conditions demonstrated here, all pores up to 0.7 mm from the surface are closed without damaging the surface, while higher peening power results in surface damage.
关键词： additive manufacturing,laser shock peening,X-ray tomography,aluminum alloys,laser powder bed fusion
更新于2025-09-11 14:15:04
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A new acoustic emission on-line monitoring method of laser shock peening
摘要： Laser shock peening (LSP) is an advanced surface modification technology that can harden metallic materials by using plasma shock waves. It has significant technical advantages and has important application value in various fields like the aerospace, defense and military. In order to realize the large-scale industrial production of LSP, it is necessary to strengthen on-line monitoring of its working status. Acoustic emission (AE) is a dynamic non-destructive technique to evaluate the material performance change in real-time, which overcomes many shortcomings of traditional non-destructive testing methods and has been successfully applied to on-line monitoring of LSP. Generally the signal and characteristic parameters of AE are affected by sensor position, which is inconvenient to evaluate the quality of LSP in unified standard. The propagation characteristics of AE and the planar positioning function of AE were concerned in this work, the AE energy of material was obtained from detected waveforms and characteristic parameters of AE by calculation, which is helpful to realize the on-line monitoring of LSP.
关键词： AE energy,on-line monitoring,planar positioning,propagation characteristics,laser shock peening,acoustic emission
更新于2025-09-11 14:15:04
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Dislocation density-based study of grain refinement induced by laser shock peening
摘要： Laser shock peening (LSP) is an innovative surface processing technique. Grain re?nement induced by LSP has been proved to be feasible to improve the surface properties of materials and prolong the service life of metallic components. The three-dimensional ?nite element model, which incorporates a dislocation density-based constitutive model and the temporal-spatial distribution of laser shock wave, was adopted to simulate the process of grain re?nement induced by LSP. The predicted dislocation cell sizes, dimple fabrications induced by the repetitive LSP of copper are in good agreement with experimental results, which con?rms the validity of the dislocation density-based three-dimensional ?nite element model. The e?ects of laser spot overlap ratio and laser power density (peak laser shock wave pressure) on LSP-induced grain re?nement were investigated in detail based on the numerical simulations of multiple LSP of copper and CP-Ti.
关键词： Laser shock peening,Dislocation density evolution,Cell size,Grain re?nement
更新于2025-09-11 14:15:04
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[Laser Institute of America ICALEO? 2016: 35th International Congress on Applications of Lasers & Electro-Optics - San Diego, California, USA (October 16–20, 2016)] International Congress on Applications of Lasers & Electro-Optics - Alteration of fracture toughness (KIC) following laser shock peening of silicon nitride ceramics
摘要： This work focuses on the development in laser shock peening (LSP) Si3N4 ceramics with a view to first observe the general effects namely; the topography, hardness, flaw size, plane strain fracture toughness (KIc). Firstly, an LSP surface treatment was conducted to establish a crack-free surface treatment. This also established a parametric window and elucidated the feasibility of treating a brittle material such as Si3N4 with a high intensity/pressure surface treatment such as LSP. Upon comparing the as-received surface with the LSPned surface elucidated a natural increase in surface roughness from an average of 1.73μm to 4.79μm. This indicated some level of material removal. In addition, a decrease in hardness was found by 4.5% and an increase in the KIc by over 21.5% through a possible induction of plasticity within the Si3N4. The microstructure of the Si3N4 also showed considerable changes after LSP surface treatment and a possible α-beta transformation were introduced which indicated surface strengthening. The work undertaken herein have shown that with further refinement of the LSP parameters, this type of laser treatment could be beneficial for strengthening advanced ceramics, particularly, as the process offers a mechanism for enhancement in fracture toughness. An alteration of such an important property of a Si3N4 would open new avenues for its applications particularly where metals and alloys fail.
关键词： hardness,surface treatment,Laser shock peening,Si3N4 ceramics,fracture toughness
更新于2025-09-11 14:15:04