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Optimizing Processing Parameters for Multi-Track Laser Cladding Utilizing Multi-Response Grey Relational Analysis
摘要： Multi-track laser cladding is the primary technology used in industrial applications for surface reinforcement and remanufacturing of broken parts. In this study, the influence of processing parameters on multi-track laser cladding was investigated using a Taguchi orthogonal experimental design. A multi-response grey relational analysis (GRA) was employed to identify laser cladding processing parameters that simultaneously optimize the flatness ratio of the coating and the cladding efficiency. The optimal parameters setting found by GRA were validated experimentally. Results showed that the flatness ratio and cladding efficiency were closely correlated to the overlap rate and laser power, where the overlap rate shows the most significant impact on the flatness ratio and the laser power shows the most significant impact on cladding efficiency. Results from the validation experiment were within one percent (0.97% error) of the predicted value. This demonstrates the benefits of utilizing GRA in laser cladding process optimization. The methods presented in this paper can be used to identify ideal processing parameters for multi-response multi-track laser cladding processes or other industrial applications.
关键词： orthogonal experimental design,grey relational analysis,multi-track cladding,laser cladding
更新于2025-11-28 14:24:20
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Microstructural Characteristics of Laser Metal Deposited Magnesium Alloy AZ31
摘要： Up to now, only a limited amount of metallic materials is investigated for laser additive manufacturing (LAM). However, the demand to widen the application possibilities by enlarging the range of materials for LAM is growing fast. By now, titanium and aluminium alloys are in the focus of research. In contrast, magnesium alloys are rarely used in the field of additive manufacturing, although they possess a low density in combination with a high specific strength. Currently, magnesium structures are mainly produced by casting but during the last years, the use of wrought alloys also increased. A reason for the rare use of magnesium alloys for LAM technologies might be the high flammability of magnesium powders. This difficulty can be avoided by using magnesium wire for laser metal deposition (LMD). In the present study, the microstructural characteristics of a LMD processed AZ31 magnesium alloy are investigated. For this purpose, optical microscopy and scanning electron microscopy were used. With the help of EDX and EBSD analysis, a change of the chemical composition and micro texture with structure height was identified. The relationship of microstructure and local mechanical properties was investigated with the help of Vickers micro hardness testing. Based on the obtained results it can be concluded that the microstructural characteristics of laser additive manufactured magnesium alloys differ from those of titanium and aluminium alloys. Thus, a wider application spectrum of LMD and magnesium alloys can be opened up.
关键词： laser metal deposition,local mechanical properties,microstructure,magnesium alloy,wire,microtexture
更新于2025-11-28 14:24:20
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Laser welding process evaluation on stake-welded T-joints
摘要： Ship structural steel EH36 sheets with thickness of 3 mm were stake-welded with T-joints by using ?ber laser beam welding (LBW). Optical microscope (OM) observation, angular distortion measurement and tensile test were conducted to investigate the in?uence of defocusing distance, welding speed and line energy on the joint properties. The experiment results showed that laser stake-welded T-joints with high quality could be obtained at 1.8 m min?1 speed high, ?5 mm defocusing distance and 5 kW power. The loss of liquid metal in the misalignment condition led to severe under?ll. In addition, laser line energy and misalignment contributed signi?cantly to welding angular distortion. The welding width between face panel and web panel exerted an important in?uence on the tensile properties. Moreover, the thermal distortion process induced by ?ber laser welding has been schematically illustrated and systematically revealed.
关键词： laser welding,angular distortion,tensile property,T-joint,misalignment
更新于2025-11-28 14:24:20
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A comparison between induction pre-heating and induction post-heating of laser-induction hybrid welding on S690QL steel
摘要： In this paper, the di?erences of microstructure and performance of S690QL steel between induction pre-heating laser-induction hybrid welding (LIHW) and post-heating LIHW were compared via scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS), electrical back-scattered di?raction (EBSD), and mechanical machines. The t8/5 values of both pre-heating and post-heating LIHW joints were shown to increase with inductor output power increasing from 60% to 80% and 100%, and each temperature curve of the post-heating LIHW weld center (WC) and heat-a?ected zone (HAZ) has two peak values. Through experimental and theoretical analyses, pre-heating LIHW joints were determined to mainly contain ferrite, bainite and little martensite, while the post-heating LIHW joints have more bainite. Except for the 80% inductor output power post-heating sample, the microstructures demonstrate dispersing phenomena, as well as weld defects. With increasing pre-heating LIHW inductor output powers, the proportion of ferrite rises, martensite and bainite contents decrease, and dislocation pileup occurs; these will lead to the decrease of microhardness and an increase in plasticity. However, in post-heating LIHW joints, the amounts of ferrite and martensite show a decreasing tendency, and the proportion of bainite tends to increase. The fracture pattern of pre-heating LIHW joints and post-heating LIHW joints is shown to be a dimple fracture, and the pre-heating LIHW joints have a better tensile strength and toughness. Thus, compared with post-heating LIHW, pre-heating LIHW is shown to be superior.
关键词： Performance,Microstructure,Laser-induction hybrid welding
更新于2025-11-28 14:24:20
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Enhancement of weld strength of laser-welded joints of AA6061-T6 and TZM alloys via novel dual-laser warm laser shock peening
摘要： In this paper, an experimental study is presented on an investigation to improve the weld strength of laser-welded joints via post-processing by warm laser shock peening (wLSP). A dual-laser setup was utilized to simultaneously heat the sample to a prescribed temperature and to perform the wLSP process on the laser-welded joints of AA6061-T6 and TZM alloys. Joints in overlap and bead-on-plate configurations were created by laser welding by a high-power fiber laser and post-processed with wLSP. The tensile tests carried out on wLSP-processed AA6061-T6 samples demonstrate an enhancement in the strength by about 20% over as-welded samples and the ductility of samples processed by wLSP improved by 30% over as-welded samples. The bead-on-plate (BOP) welds of TZM alloy processed with wLSP demonstrated an enhancement in strength by about 30% and the lap welds processed with wLSP demonstrated an increase in the joint strength by 22%. Finite element analysis revealed that the depth and magnitude of compressive stresses imparted by wLSP were greater than room temperature laser shock peening (rtLSP), which contributed to the enhancement of the joint strength for processed samples.
关键词： Al6061,Warm laser shock peening,Strength improvement,Laser welding,TZM
更新于2025-11-28 14:24:20
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A Comparative Study of Deformation Behaviors Between Laser-Welded Joints and Base Metal of Ti-22Al-24.5Nb-0.5Mo Alloy
摘要： The tensile deformation behaviors of laser-welded Ti-22Al-24.5Nb-0.5Mo alloy joints have been investigated at room temperature and 650 °C using in situ tensile analysis methods. The a2 phase had a significant influence on deformation behaviors of base metal at room temperature and 650 °C. The microcracks mainly nucleated in B2/a2 phase boundaries or within a2 phase and then propagated along B2/a2 phase boundaries subsequently. Compared with the plastic fracture of base metal, the fracture modes of the fully B2-phase fusion zone at room temperature and 650 °C were quasi-cleavage and intergranular fracture, respectively. While dislocation slips became foremost deformation mode in the fusion zone at room temperature, there were a great amount of slip bands on the surface of grains caused by the slip systems. The microcracks of fusion zone at 650 °C nucleated and propagated along the grain boundaries of B2 phase. Owing to the lack of grain deformation, the cross-slip bands were in small quantities on the surface of B2 phase grains.
关键词： in situ analysis,laser welding,deformation behaviors,Ti2AlNb alloy
更新于2025-11-28 14:24:20
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Autogenous fiber laser welding of 70/30 Cu-Ni alloy plates
摘要： Cupronickel alloys such as 70/30 Cu-Ni have excellent resistance to sea water corrosion and anti-fouling properties, and thus have been widely used for naval and offshore applications. Traditionally, arc welding and brazing processes have been used to weld such materials. In contrast, laser beam welding is a promising technology due to its high productivity, good process flexibility and reliability, and good welding integrity. In the present work, a high power fiber laser system is used to weld 5-mm thick 70/30 Cu-Ni alloy plates in a configuration of butt joints. Then, the laser welded joints are evaluated in terms of microstructures, defects, and mechanical properties (hardness, face and root bend, and tensile) in accordance with the applicable International Organization for Standardization and Defence Standard specifications.
关键词： Tensile Properties,Microstructure,Butt Joint,Cupronickel Alloy,Bend testing,Laser Welding
更新于2025-11-28 14:24:20
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Influence of laser parameters on tensile shear strength of copper welds
摘要： The electrification of the power train in the automotive industry leads to the requirement of electrical connectors with high ampacities. These connectors are often realized using ultrasonic bonding technology. Substitution of ultrasonic welding by laser welding allows an increase of ribbon cross section by a factor of 5 and thus a similar increase of the maximum transferred current. The increased cross section leads to higher loads (at least by a factor of 5) applied to the weld seam during the process. To minimize the heat input, the weld seam strength in shear direction shall be maximized. The influence of different laser parameters on the ultimate tensile shear stress in lap joint configuration is investigated, based on representative specimen geometries (10 × 0.3 mm2). The variable parameters are: laser wavelength (IR around 1050 nm + frequency doubled 515 nm), focal diameters (42–300 μm), different temper conditions of the base material, process parameters (laser power 0.6–4 kW and feed rate 50–800 mm/s), and welding strategies (single pass welding, spatial beam modulation). The material used is Cu-ETP (>99.9% Cu). For all the investigated parameters, the observed failure mode is “fracture in the fusion zone.” The ultimate tensile shear stress for all experiments is around 188 N/mm2 even for parameter changes in the order of one magnitude. This is in contrast to the assumed relation between laser parameters and the mechanical properties. This contrast will be discussed.
关键词： load-carrying capacity,ductile welds,wobbling,fiber laser welding,shear strength
更新于2025-11-28 14:24:20
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Magnetic-Field-Induced Partial-to-Full Penetration Evolution and Its Mechanism During Laser Welding
摘要： The geometry and tensile strength of magnetic-?eld-assisted laser-welded Ti-6Al-4V joints have been studied. Due to the effects of the magnetic ?eld on the melt ?ow behavior during welding, the weld penetration depth increased from 4.27 mm (partial penetration) to 5.00 mm (full penetration) and the curvature of the weld cross-section decreased, improving the weld tensile strength. The fusion zone was enlarged, showing a maximum increase of 53.4% in area when the magnetic ?eld intensity was 90 mT. The increased penetration depth and fusion zone area suggest that application of a magnetic ?eld can improve the energy utilization of the laser during laser butt welding. The mechanism of the magnetic-?eld-induced penetration depth evolution is discussed. This study provides a new energy-saving method to obtain a full-penetration weld using laser welding at lower power.
关键词： Magnetic-field-assisted laser welding,Tensile strength,Energy utilization,Ti-6Al-4V,Weld geometry
更新于2025-11-28 14:24:20
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Enhanced mechanical performance of fusion zone in laser beam welding joint of molybdenum alloy due to solid carburizing
摘要： It is unable to strengthen molybdenum (Mo) through solid-state phase transformation, while exploring the effect of carbon (C) on microstructures and properties of fusion zone (FZ) of laser beam welding (LBW) joints of Mo alloy with serious grain boundary embrittlement is significant. An analysis was made on changes of bonding strength of grain boundary and precipitates on the grain boundary surface in the FZ of Mo carburized welded joints, and the existing form and strengthening mechanism of carbon. At first, solid carburizing (SC) can achieve the goal of adding the C to welded joints and C mainly appeared as C atoms and Mo2C in Mo alloy. Afterwards, C could increase the grain boundary strength and the plasticity of grains in the FZ. Therefore, the compatibility of deformation at grain boundary and grain interior was improved. Finally, Mo2C distributing at the grain boundary can inhibit the crack propagation during the deformation. As a results, the tensile strength of carburized weld joints rose by 426% compared with that of uncarburized weld joints, meanwhile the above results provide a new idea for the method for strengthening the Mo fusion weld joints.
关键词： laser beam welding,grain boundary embrittlement,carbon,molybdenum
更新于2025-11-28 14:24:20