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Control and prediction of forming quality in curved surface multi-track laser cladding with curve paths
摘要： This research investigated the influence of different processing parameters in curved surface multi-track laser cladding with curve paths. Mathematical models of flatness ratio, incomplete fusion, and pore area in the clad were developed by central composite design with altering the input laser power, scanning speed, gas flow, and overlapping rate. Response surface methodology was used to analyze the correlation of different processing parameters affecting the selected responses. A clad with better flatness ratio was achieved by properly increasing the laser power and gas flow while reducing the overlapping rate. Appropriately increasing the laser power and overlapping rate while reducing the scanning speed and gas flow effectively diminished the incomplete fusion. Less pore area in the clad was obtained by appropriately increasing the laser power and overlapping rate while reducing the scanning speed and gas flow. Afterwards, desired processing parameters set was obtained by the optimization with the target of maximizing the flatness ratio and also minimizing the incomplete fusion and pore area. Experimental validation with this processing parameter setup provided satisfactory clad, and the error rate for the flatness ratio, incomplete fusion, and pore area was 1.708%, 5.714%, and 6.522%, respectively. This paper provides the theoretical guidance for the prediction and control of the flatness ratio, incomplete fusion, and pore area in curved surface multi-track laser cladding with curve paths.
关键词： Central composite design,Response surface methodology,Curved surface,Laser cladding
更新于2025-09-19 17:13:59
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Study on laser cladding and properties of AZ63-Er alloy for automobile engine
摘要： Aiming at the problem of the poor corrosion resistance of magnesium alloys for automobiles, Al-TiC and Al-TiC-Y2O3 cladding layers were prepared on the AZ63-Er alloy by laser cladding technology, studied the effects of Al:TiC mass ratio and Y2O3 addition on the microstructure, phase composition, hardness and corrosion resistance of the cladding layer. The results show that the Al-TiC laser cladding layer with different mass ratios has metallurgical bonding with AZ63-Er alloy substrate, and there are no pores or cracks at the interface. The main phases of the Al-TiC laser cladding layer are Ti3AlC, TiC, Mg2Al3, Al3Mg2, Al, Mg, AlMg and Ti6O. The hardness of laser cladding layer with the mass ratios of Al:TiC are 8:1, 4:1 and 2:1 are about 2.75, 3.24 and 3.94 times of the substrate. The corrosion resistance of Al-TiC cladding layer is higher than that of the AZ63-Er alloy substrate, and the corrosion resistance of the Al:TiC cladding layer with the mass ratio of 8:1 is the best. Al3Y and Al4MgY phases are formed in the Al-TiC-Y2O3 cladding layer after Y2O3 addition. The hardness of the Al-TiC-Y2O3 cladding layer is significantly higher than that of the Al-TiC cladding layer. The Al-TiC-Y2O3 composite cladding layer has the best hardness and corrosion resistance when the Y2O3 content is 0.6%.
关键词： surface modification,laser cladding,hardness,AZ63-Er alloy,corrosion resistance
更新于2025-09-19 17:13:59
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Residual stress in laser cladded heavy-haul rails investigated by neutron diffraction
摘要： Residual stress is one of the critical parameters affecting the fatigue behaviour of tribological components, which can be introduced by a thermo-mechanical process such as laser cladding. In this study, the residual stress distribution of laser cladded rails was evaluated using a neutron diffraction technique. The substrate rail for the laser cladding was hypereutectoid rail steel used in Australian heavy-haul railway track, and the cladding materials were 410L (a low carbon content stainless steel alloy) and Stellite 6 (a Co-based alloy). The cladding materials were selected based on their high wear, corrosion and fatigue resistance properties. This study measured the residual stress in full-scale laser cladded rails where the residual stresses were measured in the cladding layer, heat affected zone (HAZ) and substrate zone of the railhead. A new sample preparation strategy was developed to quantify the residual stresses in the full-scale rails with high spatial resolution. Higher compressive residual stress was found in the cladding layer, which may have resulted from the martensitic transformation occurred in that region. Tensile stresses occurred in the HAZ to a depth of 4 mm, which might be mainly caused by thermal contraction and volumetric change in the microstructure. The addition of a second cladding layer did not significantly affect the magnitude of the residual stresses, but the peak tensile residual stress shifted to a deeper location from the surface, which is beneficial in resisting wear. Post-cladding heat treatment significantly reduced the undesirable high residual stress from the cladding layer and HAZ.
关键词： Post-cladding heat treatment,Residual stress,Neutron diffraction,Laser cladding,Heavy-haul rail
更新于2025-09-16 10:30:52
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Analysis of the Source Type Influence on the Structure Forming during Aluminum Wire-Feed Laser Deposition
摘要： Most of the enterprises around the world engaged in various industrial sectors appreciated the potential of additive technologies. One such technology is direct laser deposition. The technology of direct laser deposition is most relevant for the manufacture and restoration of parts due to lower time and resource costs compared to traditional technologies. The use of wire instead of powder can reduce the consumption of filler material and improve production efficiency. The article presents the results of the study of the additive technology of direct deposition from aluminum wire using various energy sources - laser, arc, and combined laser-arc. Also presented grown samples obtained by each method. Metallographic studies were carried out to study the structure of grown samples from the aluminum alloy AlMg6Zr. Experimental work was carried out on a technological complex based on an ytterbium fiber laser with a power of up to 16 kW (LS-16) and an arc source for MIG welding.
关键词： high power laser,microstructure aluminum based alloys,laser cladding
更新于2025-09-16 10:30:52
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A convolutional approach to quality monitoring for laser manufacturing
摘要： The extraction of meaningful features from the monitoring of laser processes is the foundation of new non-destructive quality inspection methods for the manufactured pieces, which has been and remains a growing interest in industry. We present ConvLBM, a novel approach to monitor Laser Based Manufacturing processes in real-time. ConvLBM uses a Convolutional Neural Network model to extract features and quality indicators from raw Medium Wavelength Infrared coaxial images. We demonstrate the ability of ConvLBM to represent process dynamics, and predict quality indicators in two scenarios: dilution estimation in Laser Metal Deposition, and location of defects in laser welding processes. Obtained results represent a breakthrough in the 3D printing of large metal parts, and in the quality control of welding processes. We are also releasing the ?rst large dataset of annotated images of laser manufacturing.
关键词： Quality-control,Laser-cladding,Laser-welding,Convolutional-neural-networks,Neural-networks
更新于2025-09-16 10:30:52
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Modeling of thermal behavior and microstructure evolution during laser cladding of AlSi10Mg alloys
摘要： An improved three-dimensional finite element model has been proposed for studying the thermal behavior and microstructure evolution during laser cladding of AlSi10Mg alloys. Different material properties between AlSi10Mg powders and AlSi10Mg alloys are distinguished from the experiment and theoretical calculation to provide more reliable material parameters for simulation. In order to investigate the melting and solidification process during the formation of cladding layers, a temperature selection judgment mechanism is established to simulate the evolution of AlSi10Mg powders from the powder state to melting state and alloy state. In addition, to simulate the complex thermal behavior associated with powder particles and the voids between particles, a simplified exponential attenuation model is used for correcting the heat source. A complex asymmetric heat source considering about the different material properties and laser absorptivity on both sides of the remelting zone is used for multi-track cladding process. By simulating the temperature distribution of molten pool, the improved FEM could be used to predict the geometric shape of cladding layers (ignoring the effect of melting flow) and the temperature history. The simulation results show that the heat tends to diffuse to the unmelted powder owing to the asymmetric heat source during multi-track cladding, which leads to the asymmetry of cladding layers along the width direction. Based on the results of the temperature field simulations and the solidification characteristics of AlSi10Mg powders, the temperature gradient (G), solidification growth rate (R), cooling rate (G*R) and G/R are investigated to predict the morphology and size of the solidification microstructure under different laser scanning parameters. The scanning speed mainly determines the cooling rate during the laser cladding process, which results in different microstructures. Higher scanning speed leads to higher cooling rate, corresponding to a finer microstructure. Coarse dendrites are generated at the bottom of the molten pool, while finer dendrites are formed at the top.
关键词： Simulation,Microstructure evolution,AlSi10Mg alloy,Laser cladding,Thermal behavior
更新于2025-09-16 10:30:52
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[Laser Institute of America ICALEO? 2016: 35th International Congress on Applications of Lasers & Electro-Optics - San Diego, California, USA (October 16–20, 2016)] International Congress on Applications of Lasers & Electro-Optics - Rapid prototyping based on laser cladding of cp-Ti
摘要： Commercially pure titanium (cp-Ti) and titanium alloys are successful metallic biomaterials for implants because of their biocompatibility, corrosion resistance, fatigue strength, and a relatively low elastic modulus to minimize “stress shielding” and osteopenia. Nowadays, titanium components are manufactured by conventional subtractive methods, which show a set of inconveniences: titanium has low machinability, loss of high cost material during machining, and the geometrical limitation for the shapes achieved by subtractive methods. Rapid Prototyping based on Laser Cladding is an Additive Manufacturing (AM) technique that can be applied to any material which can be melted. It can be found under different names and acronyms: Laser Consolidation (LC), Direct Laser Deposition (DLD), Laser Metal Deposition (LMD), Laser Engineering Net Shaping (LENS), etc. Rapid Prototyping based on Laser Cladding can become a solution to manufacture advanced pure titanium components customized for the final user, with new geometries and/or with enhanced microstructures and mechanical properties for a better performance. In this research work, Laser Additive Manufacturing was employed to obtain simple parts made out of commercially pure titanium. Generated parts were analyzed by Optical Microscopy (OM), Optical Profilometry (OP), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) to study morphology, microstructure, and composition.
关键词： Titanium,cp-Ti,Additive Manufacturing,Rapid Prototyping,Laser Cladding
更新于2025-09-16 10:30:52
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Modeling of the Formation Process of the Coherent Intermetallides in Nickel Alloys during Laser Treatment
摘要： A solution for new phase inclusion growth is suggested for the case of the Ni-based alloys. This solution takes into account a chemical composition of the alloy and conditions of the laser treatment process. A method for calculation of the chemical reaction rate constant is also suggested for the Ni3Al formation in the Ni-Al alloy. Modeling is fulfilled for the laser cladding process. Time dependences for the reacting component concentration is obtained as well as for intermetallic inclusion growth and thermal cycle.
关键词： reaction rate constant,powder GS6U,laser cladding,Ni3Al intermetallide,new phase inclusion growth
更新于2025-09-16 10:30:52
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Study on direct laser metal deposition
摘要： In the current economic situation with worldwide trend for developing new products, the importance of time and cost reduction increases day-by-day. To achieve this goal the man-machine-material interaction should be maximized. Direct laser metal deposition (DLMD) is one of the most famous approaches for this. DLMD is one kind of 3D printing technology (Additive Manufacturing) together with laser cladding process. In DLMD, it is possible to fabricate fully functional metallic parts directly from CAD data, which involves a feeding of metal powders through a nozzle into a high power laser beam and creates a melt pool on the surface of the solid substrate upon which a metallic powder is injected. DLMD process are now acknowledged worldwide and is also known to all by several other names such as Laser engineered net shaping (LENS), Direct light fabrication (DLF), Laser deposition welding (LDW) and powder fusion welding (PFW). The role of nozzle in this process is as important as the heart of a human being. There are variety of nozzle configurations namely off-axis, continuous coaxial and discontinuous coaxial powder injection. Comparison of these types of configurations towards specific applications revels very interesting observations which are subsequently reproduced in this article. In DLMD, powder metals are fed through the nozzle onto a metallic substrate. Then, powder melts by the laser heat and creates a metal pool on the solid substrate by fusion bonding. Once the deposition of a layer, the laser head, along with the powder delivery nozzle, move up. The whole process is carried out until final near-net-shape of the metal part or component is achieved with a variety of material applicability and high quality clad track deposition with good mechanical properties. After development of this process in 1995, lot of researchers for several years work on various aspects of high quality deposition with dimensional accuracy such as good clad geometry, clad height, and microstructure study of the mechanical properties. Through this paper on the basis of literature survey an attempt has been made to focus on proper selection of the set up configuration for direct laser metal deposition to fulfill the requirement and helps to achieve high quality deposition.
关键词： 3D printing,Laser cladding,Additive manufacturing
更新于2025-09-16 10:30:52
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[Laser Institute of America ICALEO? 2015: 34th International Congress on Laser Materials Processing, Laser Microprocessing and Nanomanufacturing - Atlanta, Georgia, USA (October 18–22, 2015)] International Congress on Applications of Lasers & Electro-Optics - Hot wire laser cladding for repairing martensite precipitation hardening stainless steel
摘要： Martensite precipitation hardening stainless steel (M-PHSS) is widely used as load-bearing parts because of its excellent overall properties. It is economical and flexible to repair the failure parts instead of changing new ones. However, it is difficult to keep the properties of repaired layer as good as the substrate. Multi-pass layers were cladded on the surface of FV520B by hot wire laser cladding. Response surface methodology (RSM) was used to optimize processing parameters and predict formation quality of multi-pass cladding. Microstructure of the as-cladded layer was non-uniform and divided into quenched and tempered region. For the as-cladded layer, tensile strength was almost equivalent to that of the substrate, while ductility and impact toughness deteriorated much. With using laser scanning, microstructure of the clad layers was tempered to fine martensite uniformly. The ductility and toughness of clad layer were improved to be equivalent to those of the substrate, while the tensile strength was a little lower than that of the substrate. By adding TiC nanoparticles as well as laser scanning, the precipitation strengthening effect was improved and the structure was refined in the clad layer. As a result, the strength, ductility and toughness were all improved further. Finally, high quality clad layers were obtained with equivalent or even superior mechanical properties to the substrate, offering a valuable technique to repair M-PHSS.
关键词： Mechanical properties,Microstructure,Hot wire laser cladding,Martensite precipitation hardening stainless steel,Repair
更新于2025-09-16 10:30:52