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Experimental Optimization of Nimonic 263 Laser Cutting Using a Particle Swarm Approach
摘要： This paper presents an experimental study carried out on Nimonic 263 alloy sheets to determine the optimal combination of laser cutting control factors (assisted gas pressure, beam focus position, laser power, and cutting speed), with respect to multiple characteristics of the cut area. With the aim of designing laser cutting parameters that satisfy the specific specifications of multiple responses, an advanced multiresponse optimization methodology was used. After the processing of experimental data to develop the process measure using statistical methods, the functional relationship between cutting parameters and the process measure was determined by artificial neural networks (ANNs). Using the trained ANN model, particle swarm optimization (PSO) was employed to find the optimal values of laser cutting parameters. Since the effectiveness of PSO could be affected by its parameter tuning, the settings of PSO algorithm-specific parameters were analyzed in detail. The optimal laser cutting parameters proposed by PSO were implemented in the validation run, showing the superior cut characteristics produced by the optimized parameters and proving the efficacy of the suggested approach in practice. In particular, it is demonstrated that the quality of the Nimonic 263 cut area and the microstructure were significantly improved, as well as the mechanical characteristics.
关键词： artificial neural networks (ANNs),microhardness,laser cutting,microstructural characterization,Nimonic 263,parameters optimization,particle swarm optimization,simulated annealing (SA),surface roughness
更新于2025-09-16 10:30:52
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Microstructure and selected properties of boronized layers produced on C45 and CT90 steels after modification by diode laser
摘要： The paper presents the study results of macro- and microstructure, microhardness and corrosion resistance of C45 medium carbon steel and CT90 high carbon steel after diffusion boriding and laser modification by diode laser. It was found that the increase of carbon content reduced the thickness of boronized layer and caused change in their morphology. Diffusion boronized layers were composed of FeB and Fe2B iron borides. As a result of laser surface modification of these layers, the microstructure composed of three areas: remelted zone, heat affected zone (HAZ) and the substrate was obtained. Microhardness of laser remelting boronized layer in comparison with diffusion boronized layer was lower. The presence of HAZ was advantageous, because mild microhardness gradient between the layer and the substrate was assured. The specimens with laser boronized layers were characterized by better corrosion resistance than specimens without modified layer.
关键词： Laser remelting,Boronized layer,Corrosion resistance,Microstructure,Microhardness
更新于2025-09-16 10:30:52
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The influence of laser engineered net shaping (LENSa?￠) technological parameters on the laser deposition efficiency and properties of H13 (AISI) steel
摘要： A successful attempt at laser cladding of H13 (AISI) hot work tool steel by the laser engineered net shaping technique is presented. Technological parameters, such as laser spot diameter, powder flow rate, and deposition velocity, were changed during the experiment. The influences of the different technological parameters on the efficiency of the cladding, geometry of the clads and properties of the deposited material were investigated. As a result, 75 different samples were deposited. The efficiency of the cladding varies significantly within the chosen range of parameters and is as low as several percentage points. The chosen parameters also appear to affect the shape of the clad, size of the heat-affected zone, microstructure and hardness of the steel, which ranged from 500 to 800 HV after deposition. The proper choice of parameters led to the desired surface hardness of the deposited material, and a heat treatment of the final product may not be necessary.
关键词： Clads geometry,Direct energy deposition,Deposition efficiency,Laser cladding,Microstructure,H13 tool steel,Microhardness,LENS?
更新于2025-09-16 10:30:52
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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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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
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Creation of heterogeneous metal-ceramic structures based on Ti, Ni and WC, B4C by the combined method of laser cladding and cold gas-dynamic spraying
摘要： The paper pioneers the complex experimental investigation of the metal-ceramic coating made by the additive technologies, the combination of the cold gas-dynamic spraying (CS) and following layered laser processing. The coating is made of ceramic powders WC and В4С, the concentration in the initial mixture of 10-70 wt.%, and metal powders based on Ti+Al, the ratio 94:6 wt.%, and Ni. The result is the strategy of the production of the heterogeneous material without pores and cracks by the consequent deposition of the powder by the CS method followed by the laser action; the thickness of the coating is 4 mm.
关键词： laser action,microstructure,morphology,coating,microhardness,cold spraying
更新于2025-09-12 10:27:22
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Microhardness profiling of Ti-6Al-4V components repaired through multiple laser additive re-melt technique
摘要： Outstanding properties inherent to Ti-6Al-4V have made it become an aerospace metal work horse and a metal giant in the titanium industry where it constitutes about 60% of titanium alloy usage. However, these properties can be influenced by high temperature processes like laser additive manufacturing (LAM). LAM is a solid free-form fabrication and a materials and process parameters dependent technique that generates solid components from computer aided design (CAD) files by using a laser beam to locally melt the powder and the substrate. In this work, LAM was used to repair narrow rectangular cracks in Ti-6Al-4V plates of 99.6 % purity by depositing similar grade Ti-6Al-4V powder and incorporating multiple laser re-melt treatments in between the deposited layers using argon as shielding gas at controlled deposition and re-melt power, gas flow rate, laser spot size, powder feed rate and scanning speed. Multiple laser re-melt treatments were made, each after every two (2) deposition tracks to collapse any irregularly deposited layers present within the groove, densely fusing the melted powder with the substrate and this was maintained until the multiple deposited welds filled up the cracks. The present work therefore investigates the effects of the multiple laser re-melt treatments on the microhardness of the laser additive repaired components. The obtained results show that laser re-melt treatments induced reheat effects onto the welds which generated a fine α+β martensitic structure within columnar prior beta grains and consequently enhanced the microhardness properties in both the heat affected zones and the fusion zones of the welds made.
关键词： microhardness,re-melt,Ti-6Al-4V,laser,Additive
更新于2025-09-12 10:27:22
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Microstructure and hardness evolution of laser metal deposited AA5087 wall-structures
摘要： Wire-based laser metal deposition enables to manufacture structures with very high deposition rates in comparison to powder-based laser additive manufacturing. However, this advantage is generally accompanied with a high energy input. Thus, an accumulation of heat within the structure can result. In addition, the heat conduction conditions can also change with increasing structure height, leading to inhomogeneous microstructural formation along the part. The present study deals with the evolution of the microstructure and hardness in laser metal deposited AA5087 wall structures. In this regard, two samples processed at adapted parameters for different deposition rates are investigated.
关键词： aluminum alloy,microstructure,laser additive manufacturing,microhardness,laser metal deposition
更新于2025-09-12 10:27:22
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Microstructural Evolution and Microhardness of Direct Laser Clad TiC Dispersed Titanium Aluminide (Ti45Al5Nb0.5Si) Alloy
摘要： In the present study, the effect of TiC additions (10 wt.% and 20 wt.%) on the microstructure and microhardness of direct laser clad Ti45Al5Nb0.5Si based titanium aluminide alloy has been undertaken. Direct laser cladding has been conducted using a high power (3 kW) fiber optic delivered Nd:YAG laser (with a beam diameter of 2 mm) using a 3-axis handling system in a layer by layer fashion to on Ti-6Al-4V substrate to develop a coupon with a dimension of 10 mm x 10 mm x 5 mm. Addition of TiC leads to formation of defect free microstructures under varied parameters, except a few processing conditions. There is formation of complex carbides (Ti2AlC, Ti3AlC2 and Ti2AlC) in addition to TiC phase in the microstructure of duplex phase. There is improvement in microhardness due to TiC addition, which increases with increased quantity of TiC. Laser power and scan speed influences the microhardness, however, powder feed rate did not influence it significantly.
关键词： microstructure,XRD,microhardness,titanium carbide,Titanium aluminide
更新于2025-09-12 10:27:22
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Processing Parameters Influence on Microhardness in Laser Metal Deposited Titanium Alloy using Design if Experiment
摘要： Laser Metal Deposition (LMD) is an additive manufacturing process for producing complex parts directly from the Computer Aided Design (CAD) model of the part and for repair of an existing worn out part. The LMD process is governed by processing parameters: laser power, gas flow rate, powder flow rate and scanning speed that influence the microhardness produced during the LMD process. In this study, statistical design of experiment to was employed to investigate the influence of processing parameters on the microhardness of laser metal deposited of Ti6Al4V powder on Ti6Al4V substrate. Full factorial design was used in this study because of its ability to capture the main effects and possible interaction effects of these processing parameters. Each processing parameters was set at low and high values and a total of sixteen (16) experiments was performed and the microhardness of each sample was measured and analyzed.
关键词： Laser Metal Deposition,Titanium alloy,Processing parameters,Microhardness,Full factorial design
更新于2025-09-12 10:27:22