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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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Investigation of Crystallization Process of a Single Crystal Nickel-Based Alloy during the Laser Multilayer Cladding
摘要： The article shows the results of multilayer laser cladding of heat-resistant single crystal nickel-based alloy ZhS32-VI (CSMX-4 analogue). The influence of the main technological parameters on geometry and microstructure formation of deposited beads was investigated. Based on obtained dependencies, the regression equations are compiled for describing the shape of bead and the ratio of directional and equiaxial crystallized sections. The obtained dependencies of regime parameters nomination allow restoring the gas-turbine blades by the method of laser cladding.
关键词： gas-turbine blades,heat-resistant nickel-based alloys,laser cladding,crystallization,single crystal nickel-based alloys
更新于2025-09-12 10:27:22
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Modeling and optimization for laser cladding via multi-objective quantum-behaved particle swarm optimization algorithm
摘要： The process parameters of laser cladding have significant effects on the quality of the laser clad coating. Generally, optimizing one property usual lead to deterioration in some other performances. In this study, the influence of key parameters to preparing the CoCr1.5FeNiNb0.5 coating, namely laser beam power, scanning speed and defocus, on the dilution and residual stress were systematically researched. The polynomial model for the parameters on dilution and residual stress was designed by response surface methodology and the effect of each parameter on the responses was investigated. Then the quadratic models were used as the constraint functions and multi-objective quantum-behaved particle swarm optimization was applied to find the minimum dilution and residual stress. At last, the optimal process parameters were predicted by this algorithm and the high entropy alloy coating was manufactured. The CoCr1.5FeNiNb0.5 HEA coating consisted of FCC and Laves phase.
关键词： Dilution,Residual stress,Response surface methodology,Laser cladding,Multi-objective
更新于2025-09-12 10:27:22
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Solidification Behavior of YSZ@Ni Nanoparticles during Laser Cladding Process
摘要： In this study, yttria-stabilized zirconia (YSZ) nanoparticles with a core-shell structure (YSZ@Ni) were used to produce a YSZ/metal thermal barrier coating by the laser cladding process. The surface morphology, phase composition, and elemental distribution of the cladding layer were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS), respectively. Splashing of YSZ nanoparticles during the cladding process was reduced when they were encapsulated with nickel. It was found that primary phases of elliptically shaped YSZ and YSZ/(FeCr2O4) eutectic nanostructures formed in the center of the molten pool, whereas equiaxed YSZ crystals formed along the edges after the laser cladding. The results showed that aggregation of Ni was observed in the interlayer between the ceramic coating and the substrate. Ni-rich spheres were observed around the equiaxed YSZ crystals. Furthermore, the solidification behavior of YSZ@Ni core-shell nanoparticles was analyzed by studying the thermodynamics and kinetics.
关键词： laser cladding,YSZ@Ni nanoparticles,coating,core-shell structure,solidification behavior
更新于2025-09-12 10:27:22
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Effect of tungsten carbide partial dissolution on the microstructure evolution of a laser clad surface
摘要： Laser surface modification has been a way to promote wear resistance in dies and molds application. Previously, researchers have succeeded in enhancing surface properties through laser surface modification. The addition of particles in laser cladding process enhanced the surface properties by strengthening the modified AISI H13 tool steel structure. Controlled parameter was laser power, pulse repetition frequency (PRF) and scanning speed with a range of 1.7–2.5 kW, 30–70 Hz and 10.5–24.5 mm s?1 respectively. The powder addition executed by a preplaced method. The grain size and hardness properties of treated samples were characterized using scanning electron microscope (SEM) and hardness Vickers indenter respectively. Surface roughness was characterized using roughness tester. From the findings, tungsten carbide (WC) particles were dissolved homogenously within refined substrate grain structure at higher laser energy. Higher laser scanning speed contributed in uniform particles distribution. The grain refinement with W element in modified layer resulted in maximum hardness of 660 HV. Rapid solidification during laser processing produced metastable phase formation grain refinement, and a higher fraction of grain boundary which resulted in grain boundary strengthening, grain refinement and metastable phase formation. In this paper laser cladding of AISI H13 tool steel with micron size WC particles addition for enhanced surface properties was investigated. These findings are important to design high precision modification of die surface for high temperature forming process.
关键词： Laser cladding,Nd:YAG laser,Grain refinement,Phase transformation,Carbide dissolution,Tungsten carbide particle
更新于2025-09-11 14:15:04
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A study on microhardness and microstructural evolution of titanium/zirconium diboride cermet coatings with varying scan speeds during laser cladding on Ti6Al4V substrate
摘要： Titanium/zirconium diboride cermet coatings were deposited at different laser scan speeds on Ti–6Al–4V alloy using laser cladding technique. Microhardness of the coatings was compared with the microhardness of the substrate, while the microstructural morphologies of coatings were evaluated via scanning electron microscope with energy dispersive spectroscopy. In addition, resultant grain sizes of the coatings were observed and phases formed within the coatings were also examined. The microhardness of the coatings was seen to be four times harder than the substrate. Scanning electron microscopic images exhibited a refinement in grain size and the development of distinct microstructural features. X-ray diffraction patterns showed significant hard phases such as Al2Zr and Ti3B4 which may be responsible for the sky-rocketed microhardness values of the coatings. This study proffers profound insight on the influence of laser scan speed, during deposition, on the microhardness and microstructural morphology of titanium/zirconium diboride cermet coatings.
关键词： titanium/zirconium diboride cermet coatings,laser cladding technique,Ti6Al4V substrate,laser scan speed
更新于2025-09-11 14:15:04
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Laser cladding: from experimental research to industrial applications
摘要： In the case of aircraft jet engine blades reconditioning through cladding, it is critical to obtain a perfect bonding between the cladded layer and the substrate to prevent any loss of material during the engine exploitation, which could lead to critical failure. This paper addresses to the reconditioning of VT3-1 titanium jet engine blades through laser cladding. The experimental laser cladding reconditioning was carried out using an TRUMPH TruPulse 556 laser and a coaxial cladding head manipulated by an 9- axis robotic cell. Pure titanium powder was supplied into the coaxial cladding module for reconstruction of the damaged blade. The reconditioning process was carried out using a spot diameter of 1.8 mm and 800 W laser power at a frequency of 90 Hz. Argon was supplied as shielding gas. The engine blades were cross-sectioned and analyzed by optical and electron microscopy and EDS elemental microanalyses. The main advantages of the laser cladding process are good metallurgical bonding and lower heat input during the reconditioning process compared with other conventional remanufacturing processes.
关键词： engine blades,titanium,reconditioning,laser cladding
更新于2025-09-11 14:15:04
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Multicomponent multiphase modeling of dissimilar laser cladding process with high-speed steel on medium carbon steel
摘要： During a laser cladding process, the transport phenomena in the molten pool, including rapid solidification, strong fluid convection, and species diffusion are complex, and determine the microstructure and composition of the cladding layer. In this study, a three-dimensional transient multicomponent multiphase model was proposed to simulate the dissimilar laser cladding process with T15 powder and T15/CeO2 mixed powder on 42CrMo substrate. The position and expression of the source terms on energy and mass were clearly defined. The model was validated by comparing the morphology of the cross section with single-track cladding experiments. The simulation results indicate that the molten pool is dominated by a strong Marangoni flow that results in a fully mixed cladding layer and a narrow transition zone at the bottom. The molten pool exhibits an inward flow pattern with pure T15 powder and an outward flow pattern with T15-CeO2 mixed powder. The content of the elements and the microstructure of the cladding layer were investigated by using an electron probe micro-analyzer and a scanning electron microscope. The microstructure evolves from planar to cellular, and to equiaxed dendrites from the substrate–clad interface to the top surface. The transition zone comprised of planar and cellular grains. The solidification characteristics calculated from the numerical model were associated to the grain morphology.
关键词： Transport phenomena,Grain morphology,Laser cladding,Multiphase modeling,Marangoni flow
更新于2025-09-11 14:15:04
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Mechanical and tribological performance of fiber laser cladded h-BN + SS316 composite on SS316 surface
摘要： Laser cladding is a unique process for adding one material to the surface of another base material by utilizing high energy and coherent laser beam. For the present investigation, h-BN (hexagonal boron nitride) + SS316 composite coating was applied on SS316 substrate surface by fiber laser cladding operations. Under the influence of various input process parameters, the surface morphology, microstructure, X-ray diffraction, clad layer thickness, micro-hardness, and tribological behaviour of the composite coating were examined. The result showed good metallurgical bonding between the clad powder and substrate surface. Surface morphology did not show any pores and cracks on the clad surface. From FESEM analysis, the clad surface was found to be smooth and free from any crack propagation during laser processing. X-ray diffraction analysis showed formation of Fe3N, Cr2N, CrB, B2C5N2, γ- (Ni, Fe), h-BN phases which are responsible for enhancing mechanical and tribological properties of the clad layer. During the study, the micro-hardness of the clad layer was found to increase with an increase in % v/v of h-BN by 2-2.5 times compared (525 HV0.3) to parent material (220 HV0.3). Further, dry sliding wear test was carried out with Pin-On-Disc, showed that the coefficient of friction value decreased significantly from 0.560 (parent surface) to 0.251 (clad surface).
关键词： solid lubricant,micro-hardness,fiber laser cladding,coefficient of friction,h-BN,microstructure
更新于2025-09-11 14:15:04
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A Simple and Accurate 3D Numerical Model for Laser Cladding
摘要： A simple numerical model has been proposed for laser cladding. The model does not involve complex techniques such as cell addition, moving mesh, or prescribing a clad profile with a certain polynomial function. Instead, a mass function has been introduced to register the clad mass deposition on substrate, and from which the clad-track height can be estimated. The model takes several operational parameters, laser power, laser-head speed, and clad powder feeding rate, into consideration and predicts clad-track geometry, dilution, and substrate temperature. Experiments using two different combinations of substrate and clad powder materials to lay single and multiple clad tracks were conducted to provide data for model validation. The results show that the present model returns good agreement with experimental clad profiles for single and multiple tracks.
关键词： clad profile,numerical method,laser cladding,dilution
更新于2025-09-11 14:15:04