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The art of laser ablation in aeroengine: The crown jewel of modern industry
摘要： In this perspective, laser interaction with materials and its applications in precision engineering are mainly introduced for the manufacturing, as well as maintenance, repair, and overhaul (MRO) of aeroengines. In precision engineering, the laser ablation tool has also been more applicable considering its great advantages in microprocessing and nanofabrication. It is interesting to explore the specific process and characteristics of laser ablation, which play an important role in advanced manufacturing. Due to the complicated production procedures of an aeroengine, it is important to explore the physics behind laser interaction with aerospace and aeronautical metallic materials in order to properly utilize the unique characteristics of lasers, such as high monochromaticity, high brightness, high directivity, and high coherence. Meanwhile, it is beneficial to study the dynamic process of interactions and its mechanisms in laser applications, such as laser cleaning, texturing, and shock peening. There exist both photo-chemical and photo-thermal processes when lasers and materials interact. Several typical cases are introduced, which have great potential and high impact applications in the manufacturing and MRO industry of aeroengines. Based on laser ablation in specific industries, the building-up of MRO support system for aeroengines could be provided by a dynamic mechanism between the pioneering research results and industrial demand, leading to the fast development of advanced high-end manufacturing equipment.
关键词： precision engineering,laser interaction,aeroengine,MRO,laser ablation
更新于2025-09-23 15:21:01
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Roblems, Methods, and Algorithms in Models of Physical Fundamentals of Elements of Optical Computers
摘要： This paper considers two variants of problems that arise in developing optical computers. The first variant is related to the mathematical analysis of problems of optical bistability in the case of multibeam interaction of laser radiation in nonlinear media. The existence of optical bistability is confirmed by the results of solving the boundary value problem for a system of nonlinear ordinary differential equations. In the general case of an arbitrary nonstationary process, the problem is reduced to solving a system of two nonlinear integral equations with respect to complex amplitudes describing interference patterns. The second variant of problems is devoted to studying the absorption and scattering of light by nanomaterials. As a result, a multidimensional integral equation was obtained for the complex amplitude of the electric field. A fundamentally important feature of this equation is its singularity inside a nanoparticle.
关键词： optical computer,laser interaction,mathematical model,bistability,integral equation
更新于2025-09-19 17:15:36
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Imitating the effect of amplified spontaneous emission pedestal at relativistically intense laser interaction with nanostructured solid targets
摘要： We investigated the effect of focusing sub-nanosecond laser radiation with varied fluence onto the surface of different flat and nanostructured targets utilized in ultra-high intensity laser-plasma experiments. Thus, we modeled the action of the prepulse, referred to as an amplified spontaneous emission pedestal, typically present for a relativistic (with peak intensity over 1018 W cm?2) laser pulse with naturally limited contrast. The suppressed melting threshold was detected for the sub-wavelength scale structured material. Local melting leading to distortion of initial structures was detected at a fluence of ~0.2 J cm?2 and below, or 3–5 times lower compared to the flat substrate melting threshold. It is also demonstrated that the threshold lowering is dependent on the production method of the structures, which may be attributed to increased absorption and suppressed heat transfer into the bulk.
关键词： high intensity laser interaction,amplified spontaneous emission pedestal,laser melting,sub-nanosecond pulse,nanostructures
更新于2025-09-19 17:13:59
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Enhancing electromagnetic radiations by a pre-ablation laser during laser interaction with solid target
摘要： Ultra-short untraintense laser interacting with solid targets can produce significant electromagnetic pulses (EMPs), which are strongly pertinent to laser and target parameters. In this study, EMPs’ generation due to pulsed laser (30 fs, 6 × 1019 W/cm2) irradiating aluminum foils are recorded and analyzed. The experimental results indicate a pre-ablation pulse (200 ps, 1 × 1012 W/cm2) that tends to enhance the electromagnetic emission inside the target chamber and the diagnostic cavity. The largest EMP signal is obtained when the pre-ablation pulse is incident on the target at 100 ps prior to the main laser beam. Meanwhile, the frequencies of EMPs are broadened up to 2 GHz in the diagnostic cavity in the 100 ps delayed case, indicating that EMPs with higher frequencies can be generated if the most energetic electrons are accelerated. The simulating results verify expansion of the pre-plasmas induced by the pre-ablation laser, which is beneficial to lift both the energy and quantity of hot electrons escaping from the target, accounting for the ehancement of EMPs. The resulting conclusions offer a new avenue to generate intense EMPs, which can be potentially used in nondestructive examination, high-power microwave source, and energy transfer.
关键词： laser interaction,pre-ablation laser,hot electrons,electromagnetic pulses (EMPs),solid target
更新于2025-09-19 17:13:59
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A contribution to laser cladding of Ti-6Al-4V titanium alloy
摘要： A wear resistant coating was successfully made on an annealed Ti-6Al-4V titanium alloy by laser surface cladding using 60 wt.% WC + wt.% 40 NiCrBSi powder blends. Coaxial laser cladding was performed by means of Yb:YAG disk laser with a 3-KW continuous wave. Different laser interaction times were attempted to get the optimal conditions for promising mechanical properties. The new contribution was to accomplish larger clad layer thickness with applying the shortest possible laser interaction time that can achieve superior clad layer properties. This will decrease energy consumption with an expected money saving which is an essential factor for successful engineering solutions. A high powder ?ow rate of 20 g.min(cid:1)1 was intended in order to obtain a thick, nonporous and crack free clad layer. The clad samples were subjected to thorough microstructure investigations, in addition to microhardness and wear evaluation. The coating so produced exhibits multiple hardness values and exceptional wear resistance under adhesive/sliding wear conditions. The obtained results expose clad layer with superior quality that was achieved at a laser interaction time of 0.3 s. An enhancement in the microhardness values of the clad layers by more than fourfold was attained and the wear resistance was thus signi?cantly improved.
关键词： coaxial laser cladding process,titanium alloy,laser powder cladding,laser interaction time,microhardness,laser surface treatment,wear resistance
更新于2025-09-12 10:27:22