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Helical milling of bore holes in Ti6Al4V parts produced by selective laser melting with simultaneous support structure removal
摘要： Selective Laser Melting (SLM) is a powder bed based Additive Manufacturing (AM) process that is currently being established in the series production of Ti6Al4V components in the aviation industry. One advantage is the significantly lower Buy-to-Fly ratio. However, subsequent machining is necessary in order to remove support structures of the SLM process and to fulfill quality requirements. Experimental results on support structure removal and simultaneous finishing of holes by helical milling are presented. Engagement conditions in helical milling are strongly influenced by the support structure. Material removal rates in both peripheral and axial direction are calculated and agree well with the variation of measured forces in these directions. In addition, the surface roughness of the machined holes is affected by the support structure design and may change along the hole perimeter. The findings indicate how support structures should be designed in order to obtain high quality bore holes in one machining step.
关键词： titanium,helical milling,support structure removal,modeling,force,surface roughness,SLM
更新于2025-09-12 10:27:22
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Study the Effect of Changing the Surface Roughness and the Laser Focus Distance to the Aluminum Appearance using Picosecond Laser
摘要： Picosecond laser device is used to treat Aluminum samples, the appearance of the treated samples is affected by the variation of laser focus distance and the samples surface roughness. Samples with smoother surface before laser treatments show dark colors and high increase in surface roughness after laser treatments, while samples with rougher surfaces before laser treatments show brighter colors with slightly change in surface roughness after the laser treatments. The surface texture, topography, and roughness of the treated samples is characterized to identify the mechanism driving appearance change. The characterization results indicate that size and shape of laser processing induced microscale cavities on the surface may account for the differences in samples appearance.
关键词： Aluminum Appearance,Picosecond Laser,Focus Distance,Surface Roughness
更新于2025-09-12 10:27:22
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Cr12MoV Die Repair Experiment Based on Laser Cladding with Wire
摘要： In this paper, SKD11 steel wire has been deposited on Cr12MoV plate using Nd: YAG pulsed laser for repairing the die surface damage. The effects of laser power, wire feeding speed, scanning speed and surface roughness on clad geometry have been studied with OM and LSCM. hardness distribution of the cladding layer is also obtained by microhardness tester. Experiment results indicate that the surface roughness is important for clad characteristics due to the light trapping effect. With the increases of roughness, the laser absorption ratio can be raised, both the clad depth and the dilution rate increase, the height decreases. The essence of influence mechanism is effective body energy Ev and specific filling rate ω, and can be used as critical process factors. When Ev is 80~100 J/mm3 and ω is 1~3, a flat cladding layer can be obtained with low dilution, less fusion defects and high hardness.
关键词： laser cladding with wire,clad geometry,hardness,Cr12MoV,surface roughness
更新于2025-09-12 10:27:22
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Characterization and tribological evaluation of NiCrMoNb and NiCrBSiC laser cladding on near-α titanium alloy
摘要： In the present study, two different types of coatings such as NiCrMoNb and NiCrBSiC were produced on titanium alloy using a high power Yb:YAG disk laser. Then the coatings were analysed to expose their phase characterization, microstructure and hardness using X-ray diffraction analysis (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), optical microscopy (OM) and Vickers microhardness machine (HV). Further, tribotest was performed through ball-on-plate machine to analyse the wear properties of coatings. In addition, worn surfaces of cladding and surface roughness were examined using FE-SEM and whitelight interferometer, respectively. The results showed that the both NiCrMoNb and NiCrBSiC cladding exhibited a dendrite homogeneous structure due to higher cooling rates. XRD results indicating that the solid solution of γ-Ni was mixed with chromium, boride, silicon and formed the structure of interdendritic eutectics on cladding region. Microhardness of the clad layer has remarkably been increased than substrate. The results of friction coefficient of specimen with NiCrBSiC are lower than that of specimens NiCrMoNb clad and substrate. Also, the wear resistance of NiCrBSiC clad has been increased than NiCrMoNb clad and substrate sample, which reveals that NiCrBSiC laser cladding plays a major role on wear resistance. The microstructures of NiCrMoNb and NiCrBSiC cladding layer are composed of Ni-rich austenitic, Cr, Mo, Nb and carbide, borides, respectively. The analysed wear track indicates that adhesion and abrasion was a major wear mechanism. The NiCrSiBC cladded worn-out surfaces exhibited reduction in surface roughness than NiCrMoNb clad and substrate.
关键词： NiCrBSiC,Cladding,Microstructure,Titanium alloy,Surface roughness,Wear mechanism,NiCrMoNb
更新于2025-09-12 10:27:22
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Control of short-pulsed laser induced periodic surface structures with machining -picosecond laser nanotexturing with magnetic abrasive finishing-
摘要： An active area of research is the altering of surface functions (e.g., wettability and cell adhesion) by controlling fine surface structures such as laser-induced periodic surface structures (LIPSS). It has been found that micrometer-scale grooving (produced, for example, using ultraprecision cutting) followed by short-pulsed laser irradiation can result in efficient LIPSS coverage of a large area. However, micrometer-scale grooves can remain on the surface after short-pulsed laser irradiation. In this paper, to clarify the phenomenon and processing principle of groove-assisted short-pulsed laser irradiation, a finite-difference time-domain simulation is developed and experiments are conducted using 304 stainless steel and nickel-phosphorus (Ni–P) plating layer substrates. The use of magnetic abrasive finishing (MAF) is proposed for fabricating sub-micrometer-deep straight grooves with various peak-to-peak distances (pitch length) prior to the short-pulsed-laser irradiation. The subsequent short-pulsed-laser irradiation produces sub-micrometer-deep straight structures superimposed on the MAF-produced surface. While the pattern and depth of LIPSS are influenced by the groove depth made by MAF prior to the short-pulsed laser irradiation, the pitch length of LIPSS is dependent on the laser wavelength. This demonstrates the ability of MAF to produce grooves that guide the LIPSS and the efficacy of the developed method for fabricating fine LIPSS. The geometry of the sub-micrometer deep grooves—made prior to the short-pulsed laser irradiation—is the dominant factor in determining the pattern and geometry of the LIPSS.
关键词： Straight sub-micrometer groove,Surface roughness,Magnetic abrasive finishing,Short-pulsed laser
更新于2025-09-12 10:27:22
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Prediction of surface roughness and material removal rate in laser assisted turning of aluminium oxide using fuzzy logic
摘要： Processing of ceramics with good surface integrity and high material removal rate is a challenging task in the manufacturing industry. Laser assisted machining (LAM) is one of the benchmark technique currently used in industry to process difficult to machine materials. In LAM, laser is used as source to heat the work piece and simultaneously remove the softened material by cutting tool without changing the material microstructure. Since many process parameters are involved in LAM, experimental investigation of processing of ceramics is expensive. So the main objective of this present work is to develop an Artificial Intelligence model to understand the process mechanics and for the prediction of surface roughness and material removal rate (MRR) during laser assisted turning of Aluminium oxide using fuzzy logic. Input parameters are assumed as triangular and Gaussian function and output parameters are assumed as trapezoidal function. It is inferred that increase in cutting speed and pulsed frequency of laser, there is an improvement in surface finish, whereas increase of feed rate results in deterioration of surface integrity. The material removal rate is directly proportional to feed, speed, depth of cut and pulsed frequency of laser. There is a better agreement between experimental and fuzzy model values. The proposed model predicts the surface roughness and MRR with prediction error of 15.76 and 7.69 % respectively.
关键词： material removal rate,Laser assisted machining,fuzzy logic,surface roughness,Ceramics
更新于2025-09-12 10:27:22
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Effect of imidazole based polymer blend electrolytes for dye-sensitized solar cells in energy harvesting window glass applications
摘要： The exploration of polymer electrolyte in the field of dye sensitized solar cell (DSSC) can contribute to increase the invention of renewable energy applications. In the present work, the influence of imidazole on the poly (vinylidene fluoride) (PVDF)- poly (methyl methacrylate) (PMMA)-Ethylene carbonate (EC)-KI-I2 polymer blend electrolytes have been prepared. The different weight percentage of imidazole added into polymer blend electrolytes has been prepared by solution casting. The prepared films were characterized by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), UV-visible spectra, photoluminescence spectra and impedance spectroscopy. The surface roughness texture of the film was analyzed by atomic force microscopy (AFM). The ionic conductivity of the optimized polymer blend electrolyte by impedance measurement, which is 1.95×10-3 S cm-1 at room temperature. The polymer electrolyte containing 40 wt% of imidazole content exhibits the highest photo-conversion efficiency of 3.04% under the illumination 100 mWcm-2. Moreover, a considerable enhancement in the stability of the DSSC device was demonstrated.
关键词： Polymer blend electrolyte,Imidazole,Dye-sensitized solar cell,Surface roughness,Ionic conductivity
更新于2025-09-12 10:27:22
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Study of heat treatment impact on the surface defects appearance on samples obtained by selective laser melting of Ti-6Al-4V during chemical polishing
摘要： Among advantages of selective laser melting (SLM) there are some problems in titanium alloys surface roughness after the sintering. Present work illustrates results of roughness measurements of Ti-6Al-44V titanium alloy samples after selective laser melting, heat treatment, mechanical brushing and acid polishing. It was found that surface roughness of SLM samples depends on heat treatment and chemical polishing modes; the biggest roughness is noted after the oil quenching from 950 (cid:1)C with subsequent aging at 650 (cid:1)C during 120 min. The best surface quality was obtained after annealing for 2 h at 650 (cid:1)C, water quenching at 950 (cid:1)C, mechanical brushing and chemical polishing.
关键词： Chemical polishing,Titanium alloy,Heat treatment,Selective laser melting,Surface roughness
更新于2025-09-12 10:27:22
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Surface roughness alterations of zirconia implants after Er:YAG laser irradiation: a preliminary study
摘要： Objective This study aimed to investigate the surface roughness parameters (Rp in μm) of zirconia implants (TAVDental) after erbium YAG (LiteTouchTM) laser irradiation. Material and methods Implants were randomized into two groups according to the laser irradiation parameters (1.5 W/10 Hz and 1.5 W/30 Hz). The surface topography of each implant was analyzed before and after laser irradiation using laser-scanning microscopy. The roughness values from three different areas (cervical, middle, and apical) of each implant were registered. Result Irrespective of the different laser settings and implant surface areas, both groups showed a significant reduced mean and peak surface roughness values after laser irradiation. However, no signs of thermal defects were observed. Conclusion Based on the conditions of this preliminary study, it can be concluded that the use of the Er, YAG (1.5 W, 10 and 30 Hz) is a safe tool for zirconia implant surface decontamination.
关键词： Er:YAG laser,Implant surface decontamination,Implant surface roughness alterations,Zirconia implants
更新于2025-09-11 14:15:04
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Experimental investigation and modeling of heat affected zone and surface roughness in erbium-doped fiber laser cutting of CFRP composite
摘要： In the current era, two types of the composite, namely polymer-based composites and metal matrix composite materials are used in the industrial application, and the demand for an increase in its production is rapidly growing. But these composite materials are not so widely acceptable in the industries due to its non-machinability nature by conventional methods. Various reasons like the incorporation of defects, high strength, and hardness of the composite make the production of intricate shapes not easily achievable by traditional methods which lead to the development of new non-conventional machining methods. Laser machining method is one of the non-conventional methods which are becoming popular for cutting of composite materials due to its advantages of fast cutting speed and no contact with the workpiece. In this experimental work, an erbium-doped fiber laser is used to study the machinability of carbon fiber reinforced polymer composite and effect of various machining parameters are observed on the performance responses like heat affected zone and surface roughness. It was found that composite was easily machinable with some surface defects which were detected by SEM images. The decrease in power with an increase in scan speed and standoff distance reduces surface roughness and heat affected zone in the material.
关键词： Fiber Laser,CFRP composite,HAZ,RSM,Surface roughness
更新于2025-09-11 14:15:04