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Sustainable manufacturing: re-contouring of laser cladding restored parts by machining method with cutting energy management
摘要： Laser cladding has been commonly utilized for restoring high value-added parts. However, the poor surface quality becomes key technological barrier which restricts its widespread applications. In the paper, re-contouring strategies by machining method are explored for minimal energy consumption as well as required surface roughness. Firstly, the effect of structural characteristics of the laser-cladded workpiece on specific cutting energy was explored by means of layer-by-layer turning and orthogonal cutting. Results indicated that the specific cutting energy increased, and the machining chatter/vibration exacerbated with decreasing coating thickness under fixed cutting parameters. The reason can be summarized as a result of the effect of elastoplastic deformation behavior across the interface. Then, the influences of depth of cut and feed on specific cutting energy in finish turning were addressed. Results indicated that the specific cutting energy reduced with increasing depth of cut and feed in the form of power functions. In addition, energy efficiency decreased with an increase in uncut chip thickness and cutting speed. On basis of this work, large feed and low cutting speed with the adoption of wiper inserts were recommended for minimizing energy consumption within surface roughness requirement.
关键词： Energy efficiency,Sustainable manufacturing,Specific cutting energy,Laser cladding,Surface quality
更新于2025-09-23 15:21:01
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The Analysis of Fiber and CO <sub/>2</sub> Laser Cutting Accuracy
摘要： The aim of the conducted research was to compare the functional properties and the cutting accuracy of items produced using Fiber lasers in comparison with CO2 lasers. The object of 6 mm thick sheet plates made of S235JR steel cut with the two different laser types were analyzed. The tests covered dimensional accuracy (in accordance with the PN EN 22768-fH standard) and the surface after cutting (in accordance with the PN-EN ISO 9013: 2017-04). The results of the analysis have demonstrated that for the same welding linear energy, more accurate cutting surface is obtained using Fiber laser cutting.
关键词： CO2 lasers,Fiber lasers,S235JR steel,surface quality,cutting accuracy,dimensional accuracy
更新于2025-09-19 17:13:59
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Investigation on laser-induced oxidation assisted micro-milling of Inconel 718
摘要： Poor surface quality and rapid tool wear are the main problems in micro-cutting of Inconel 718. In this study, a novel hybrid machining method named laser-induced oxidation assisted micro-milling is proposed to solve the aforementioned problems. A loose oxide layer and a relatively flat sublayer are formed on the material after laser irradiation. Under optimized laser parameters with a scanning speed of 1 mm/s and an average laser power of 4.5 W, the thicknesses of the oxide layer and the sublayer are 24 and 18 mm, respectively. The influence of cutting parameters on milling force, surface roughness, surface quality, and top burr size is studied in detail. Cutting force and thrust force in the proposed hybrid machining process are lower than those in the conventional micro-milling. Results show that for the investigated range of parameters, the optimal feed per tooth and depth of cut in the hybrid process are 3 mm/z and 3 mm, respectively. When using the optimal parameters, the surface roughness of the machined slot bottom is 108.5 nm. The top burr size on the up-milling side and the down-milling side is 26.8 and 36.2 mm, respectively. In addition, the tool wear mechanism is coating delamination in hybrid process, whereas chipping, coating delamination, tool nose breakage, and adhesion are the main tool wear mechanism in the conventional micro-milling. For the same amount of material removal, the proposed hybrid process can decrease the tool wear and enhance the service life of the micro-end mill as compared to conventional micro-milling.
关键词： micro-milling,Inconel 718,surface quality,tool wear,laser-induced oxidation
更新于2025-09-19 17:13:59
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Study on laser-induced oxidation modification coupled with micro milling of WC-Co cemented carbide
摘要： Cemented carbide is known as “industrial tooth” and has wide applications in terms of military, aerospace and other fields. In this study, a compound processing approach named laser-induced oxidation modification coupled with micro milling (LCMM) is proposed to solve its poor micro machining performance. The oxidation mechanism of WC-Co cemented carbide is revealed. Surface morphology and cross-section of WC-Co cemented carbide are investigated after laser irradiation under various average laser power and two reaction environment. Research results present that at the average power of 5 W, scanning speed of 0.5 mm/s and oxygen-rich oxygen condition, the laser-induced oxidation process is optimal. The thickness of oxide layer and sub-layer is 9.1 μm and 2.7 μm, and the material surface generates porous and loose oxide layer. In addition, comparative analyses are performed and discussed in detail considering milling force, tool wear and surface quality of machined micro slot. In comparison with conventional micro milling (CONM), cutting force of Fx and thrust force of Fy generated in removing the oxide layer in LCMM are reduced by 56% and 58% to maximum extent, respectively. The machined surface quality in LCMM is better than that in CONM with a slower rate of increase in surface roughness (Sa). At ap = 2 μm and fz = 1.5 μm/z, surface quality of machined micro slot in LCMM is superior to that at other milling parameters, and the surface roughness reach 57 nm. Tool wear rate in LCMM is greatly improved and tool wear mechanism mainly includes slight adhesion wear and abrasion wear. While, in CONM the wear mechanisms are severe abrasion wear, chipping and adhesion wear. The tool service life in LCMM can be promoted more than double.
关键词： Micro milling,Surface quality,Cemented carbide,Laser-induced oxidation,Tool wear
更新于2025-09-16 10:30:52
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3D laser scanning for monitoring the quality of surface in agricultural sector
摘要： The paper considers three technologies for obtaining data on the road surface - through video recording, thermal imaging and laser scanning for the purpose of monitoring, diagnostics and control of the road quality. An analysis of the first two methods showed their significant drawbacks, such as the inability to measure the geometric parameters of deformations (video recording) and the significant dependence of the measurement results on external conditions (thermal imaging). Laser scanning, on the contrary, has a number of advantages, including coordinate referencing, obtaining a three-dimensional model, its transformation and measurement of parameters. Laser scanning is widely used, but mainly for measuring the quantitative characteristics of objects. The paper discusses the application of the laser scanning method to determine the qualitative characteristics of the road surface - the presence or absence of defects, which include hollow spots, waves, cavities, chipping, bleeding, humps, cracks, vertical displacement of road plates, rutting, unevenness of patching, damage to the road surface, track, breach, destruction of the pavement edge, subsidence followed by a complex of repair work. For this, a ground-based laser scanning was performed, the results of which were processed using the Leica Cyclone 9.4 software. According to the scanning data, defects were detected in the form of soil subsidence, hollow spots and humps. The performed work revealed a drawback of the laser scanning method, which consists in the absence of automated detection and recognition of deformations. A number of measures have been proposed to improve this drawback, which slows down the randomness and quality of work in monitoring and diagnosing the road. Further prospects for research on this topic, in particular the multi-purpose use of scanning data, by creating a distributed ledger are also indicated.
关键词： agricultural sector,3D laser scanning,road surface quality,monitoring,defects detection
更新于2025-09-16 10:30:52
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Process planning guidelines in selective laser melting for the manufacturing of stainless steel parts
摘要： Selective laser melting (SLM) is now, one of the most widespread Additive Manufacturing processes, due to presence in the market and known capabilities for the fabrication of mechanical components, with acceptable levels in geometrical accuracy, surface quality and mechanical properties. However, the metalworking industry is still skeptical for its full adoption in realistic production schemes, because of the lack of non-scholarly knowledge for calibrating process parameters among other technical barriers. In this work, several process planning guidelines are presented as a result of a SLM process calibration for a selected material (stainless steel 316L), with the intention of contributing in process parameters selection in net shape manufacturing. In order to conceive a proper set of guidelines for selective laser melting set up, several parameters were taken into account such as point distance, hatch distance, exposure time among others, with the aim of obtaining appropriate surface quality and good mechanical tensile behavior. Parts were obtained with good surface quality, presenting stable and well-defined weld lines and low presence of partially sintered particles adhered to the surface. After the application of the methodology, top and lateral surface roughness were improved, reaching values of Ra 5.81 and 9.61 μm respectively. In addition, good mechanical properties were obtained, of up to 500 MPa of ultimate tensile strength and 400 MPa of yield stress, comparable to the properties of sintered stainless steels alloys studied in previous works.
关键词： powder bed laser melting,roughness,surface quality,process planning,selective laser melting
更新于2025-09-12 10:27:22
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Effect of initial surface topography during laser polishing process: Statistical analysis
摘要： Surface finish is one of the most important quality characteristics of fabricated components. Laser polishing (LP) is one of the advanced manufacturing surface finishing techniques that has been recently developed and successfully employed for improving surface quality without deteriorating the overall structural form through surface smoothing by melting and redistributing a thin layer of molten material. This paper advances the statistical analysis of the LP process emphasizing aspects of the effect of the initial surface topography. Flat and ground initial surfaces are used for comparative statistical analysis of initial and polished profiles obtained experimentally. Their profile geometries and surface quality characteristics, such as, roughness, were compared and analyzed. In addition, LP process was experimentally investigated as a thermodynamic operator represented by a transfer function and it was examined by means of a coherence function.
关键词： statistical analysis,initial topography,Laser polishing,travel speed,laser power,surface quality,roughness
更新于2025-09-12 10:27:22
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Investigation on geometric precision and surface quality of microholes machined by ultrafast laser
摘要： The geometric precision and surface quality of film cooling holes has significant influence on the cooling efficiency and fatigue life of turbine blades. In this paper, the investigation about fabrication process of film cooling holes on the single crystal superalloy DD6 plate specimen by ultrafast laser is carried out. By comparing three different processing paths, minimum roughness of hole wall could be obtained by concentric circular scanning, which was used in the followed-up experiment. The influence of process parameters on the geometric precision and surface quality of microholes was analyzed, and the physical mechanism was examined. The results show that among several process parameters, focus position has the most significant influence on the microholes geometric precision and surface quality, and that the divergent beam (where the focal plane is above the machined surface) can lead to smaller taper, roundness, and surface roughness. In addition, besides a layer of solidified debris adheres to the inner wall at the hole entrance, the microholes machined by ultrafast lasers have no other defects such as a recast layer, microcrack or heat affected zone.
关键词： Geometric precision,Surface quality,Process parameter,Ultrafast laser,Microhole drilling
更新于2025-09-12 10:27:22
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Effects of laser-assisted grinding on surface integrity of zirconia ceramic
摘要： Zirconia ceramics has an important position in the field of biomaterials because of excellent mechanical properties. Because of abrasive resistance and hardness, conventional machining of zirconia ceramic is difficult and time-consuming. A nontraditional hybrid laser-assisted grinding (LAG) system combining laser and cubic boron nitride (CBN) grinding wheel was developed for machining zirconia ceramic. This hybrid system utilizes the outstanding thermostability of zirconia ceramic: The material present on the cutting path is rapidly removed by local laser heating and grinding wheel. A combined theoretical and experimental study was performed to evaluate different modes of machining of zirconia ceramic. The machining parameters were predicted by numerical analysis. The surface quality, surface morphology, and subsurface damage of zirconia ceramic specimens were analyzed and compared. The results show that LAG can easily achieve ductile regime grinding in the same machine tool. Compared with conventional grinding, the surface integrity of zirconia ceramic was significantly improved by the LAG process. LAG could achieve ductile regime grinding with a large depth-of-cut. It changes the machinability of zirconia ceramic.
关键词： Surface quality,Surface morphology,Laser-assisted grinding,Zirconia ceramic,Subsurface damage
更新于2025-09-11 14:15:04
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Research on the Relationship between Cutting Force and Machined Surface Quality in Micro Ball End-Milling of Potassium Dihydrogen Phosphate Crystal
摘要： Potassium dihydrogen phosphate (KDP or KH2PO4) crystal is widely used as terminal frequency converters in inertial confinement fusion (ICF). However, KDP crystal is a typical difficult-to-cut optical crystal with the characteristic of soft-brittle. In this work, the relationship between cutting force and processed surface quality in micro ball end-milling of KDP crystal with various depth of cut and spindle speed is studied by carried out the micro-milling experiments. Fast Fourier Transform (FFT) algorithm is used to diagnose the recorded cutting force. The periodic change of cutting force and the cutting force after filtering noises can be got through FFT analysis. Through calculating the correlation coefficients between the static component of thrust force and roughness value Ra of machined grooves, as well as the peak-valley (P-V) value of thrust force and dimensional error of machined grooves, the roughness value Ra and dimensional error of machined grooves would be predicted by monitoring the static component and P-V value of the thrust force, respectively. The relatively large spindle speed helps to reduce the roughness value Ra. The spindle speed with moderate value is recommended to reduce the dimensional error of machined groove because the dimensional error of machined groove will increase when the spindle speed is small enough (causing brittle cutting) or large enough (reducing cutting stability).
关键词： micro ball end-milling,KDP crystal,cutting force,FFT analysis,machined surface quality
更新于2025-09-10 09:29:36