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Effect of beam wobbling on laser welding of aluminum and magnesium alloy with nickel interlayer
摘要： The influence of conventional laser keyhole welding and beam wobbling was evaluated at two weld travel speeds and power settings. Fracture in linear lap welds would occur during specimen preparation due to the presence of Al-rich brittle fusion zone, unless one utilizes a circular laser wobbling path (at 1000 Hz). Wobbling provided better integrity due to the presence of a Mg-rich ductile fusion zone and a larger bonded width. It can be concluded that laser beam wobbling enhances joint quality by widening the joint area and mitigating formation of brittle secondary phases at the joint fusion zone.
关键词： Aluminum,Magnesium,Interlayer,Laser welding,Beam wobbling,Microstructure
更新于2025-11-28 14:24:20
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[Communications in Computer and Information Science] Data Mining Volume 996 (16th Australasian Conference, AusDM 2018, Bahrurst, NSW, Australia, November 28–30, 2018, Revised Selected Papers) || Effect of Nickel Foil Thickness on Microstructure and Microhardness of Steel/Aluminium Alloy Dissimilar Laser Welding Joints
摘要： Laser lap welding between DP980 steel and 6061 aluminum alloy was carried out using IPG YLS-6000 fiber laser, nickel foil with different thickness (0.10, 0.20 and 0.30 mm) was used as interlayer. The microstructure was observed by SEM, EDS was used to determine the distribution of elements and intermetallic compounds types, and the hardness was determined by HV1000IS. The results showed that the microstructure in weld seam (WS) and fusion line (FL) of welded joint without nickel foil was d ferrite and lath martensite (LM). For welded joints with nickel interlayer, the d ! c phase transition was promoted by nickel elements. Thus, with the thickness of the nickel foil increased, the content of nickel elements in weld pool increased, resulting in decrease of d ferrite content in WS and FL. Meanwhile, the microstructure in WS and FL was full LM when the thickness of the nickel foil was 0.30 mm. Meanwhile, the NixAly IMC was found in interface, which inhibited Fe–Al metallurgical reaction and reduced the thickness of Fe–Al IMC. Therefore, with nickel foil thickness increased, the content of nickel elements and the NixAly IMC increased. Moreover, the maximum thickness of the IMC layer was able to reduce to 10.66 when the thickness of the nickel foil was 0.10 mm. With the reduction of d ferrite content in WS and FL, the microhardness in WS increased with the thickness of the nickel foil increased. However, because the NixAly IMC was a soft phase, the microhardness in interface decreased, significantly.
关键词： Steel,Processing,Aluminum,Laser welding
更新于2025-11-28 14:24:20
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Butt welding-brazing of steel to aluminum by hybrid laser-CMT
摘要： A laser penetration welding-brazing combined with Cold Metal Transfer (CMT) arc, was proposed to improve weld shape and interfacial reaction inhomogeneity of 5052 aluminum alloy and Q235 low carbon steel with ER5356 welding wire in butt joint. The effects of wire feed speed, beam offset and welding speed on weld shape, interfacial microstructures and tensile strength of joints was studied. This method improved the undercut defect existed in butt laser welding-brazing, obtained well-formed joints and promoted the uniform distribution of the interface reaction. The interfacial intermetallic compounds (IMCs) layer consisted of Fe2Al5 and Fe4Al13 and the thicknesses were controlled to 3-5 μm. Microstructures of weld seam was composed of α-Al and Al3Mg2. The brittle IMCs layer thickened and then the tensile strength decreased with increasing the wire feed speed. The thickness of the IMCs layer decreased but weld shape became worse when the welding speed or the offset increased. The tensile strength increased first and then decreased. The highest tensile strength reached higher than 80 MPa and the joint fractured in IMCs layer along the interface.
关键词： intermetallic compound,Laser–CMT arc hybrid welding-brazing,dissimilar metals welding,low carbon steel,aluminum alloy
更新于2025-11-28 14:24:20
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Electrochemical synthesis of Al–Al <sub/>2</sub> O <sub/>3</sub> composites for selective laser melting
摘要： Novel electrochemical method for obtaining Al–Al2O3 composites for selective laser melting technology has been studied. The electrochemical cell with the flexible cathode and the anode device has been developed. The initial aluminum powder was characterized: aluminum content was more than 99.8 wt %; the average particle diameter was ～40 μm. Oxidized aluminum powder was studied: γ–Al2O3 in the surface oxide layer form was detected; the increase in the particle diameter was 10–20 μm. Electrochemical oxidation technological parameters have been studied. At 0.1 A cm cathodic current density electrolysis duration was 220 min, 24 V voltage along with 80 ° C electrolyte temperature reached. The oxidation mechanism of aluminum particles has been developed. The increase in the surface oxide layer occurred, and this led to an increase in voltage. The 3D object from the oxidized aluminum powder was synthesized by selective laser melting method. The 3D object was perfectly sintered and did not crumble. Good reinforcements distribution in the volume of the synthesized 3D object has been achieved.
关键词： reinforcements,anodic oxidation,electrolysis,aluminum–alumina composites,selective laser melting
更新于2025-11-21 11:24:58
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Laser Welding of Dissimilar Metal Joint of 6061 Al Alloy and Al Matrix Composite
摘要： In this paper, dissimilar metal joints of 6061 aluminum alloy and aluminum matrix composite material are investigated by laser welding. TiB2 particles were added into the lap joint. The welding process, microstructure, and the corrosion properties of welding joints are examined. The results demonstrate that the selected optimization process parameters are laser power 6 kW, welding speed 0.6 mm/s, pulse width 11.5 ms, and laser frequency 4.5 Hz. There are a few obvious pores in the molten pool. Al2Ti, Fe2Si, and Al0.5Fe3Si0.5 are present in the microstructure. During the welding process, some TiB2 particles are decomposed and reacted with molten Al. Other TiB2 particles are nucleated and solidi?ed, and the excess TiB2 particles are pushed to the grain boundaries by molten Al. TiB2 particles are wetted well by molten matrix metal. The corrosion resistance of alloys in di?erent conditions decreased in the following order: the weld beam >6061 Al > AMC.
关键词： aluminum matrix composite,laser welding,TiB2 particles,microstructure,6061 aluminum alloy,dissimilar metal joints,corrosion properties
更新于2025-11-21 11:18:25
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Effect of graphene on corrosion resistance of Micro-arc oxidation coatings on 6061/7075 dissimilar laser-MIG hybrid welded joint
摘要： Corrosion behavior of a laser-metal inert gas hybrid (Laser-MIG) welded joint with dissimilar aluminum alloys was investigated. Micro-arc oxidation (MAO) coatings with and without graphenes were prepared on the surface of the welded joint. The effects of graphenes on the structure and corrosion resistance of the MAO coatings were studied. The welded joint was divided into five zones to investigate corrosion inducements in different zones. The heat-affected zone of 7075Al (7-HAZ) was found to be most susceptible to corrosion. Although the substrates in different zones had heterogeneous microstructures and phase compositions, the MAO coatings in different zones displayed relatively uniform surface morphology, structure, and phase composition. The MAO treatment significantly improved the corrosion resistance of welded joints. In addition, ceramic-graphene composite coatings exhibited slightly better corrosion resistance than a simple coating without graphenes due to structural changes in the coating.
关键词： Corrosion resistance,Aluminum,Graphene,Laser-MIG hybrid welding,Micro-arc oxidation
更新于2025-11-21 11:18:25
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Plasmonic Metasurfaces with Tunable Gap and Collective SPR Modes
摘要： Optical properties of a plasmonic metasurface made of a monolayer of gold nanoparticles in close proximity to an aluminum thin film were studied numerically and experimentally. Extinction spectra of the plasmonic metasurface were studied as functions of the thickness of a dielectric spacer between the monolayer of gold nanoparticles and the aluminum film in the visible wavelength range. The goal was to understand the excitation of a collective surface plasmon resonance (SPR) mode and a gap plasmon mode as well as their dependence on the spacer thickness, nanoparticles spacing and their size. By using finite-difference-time-domain (FDTD) calculations we find that the SPR extinction peak first red-shifts and then splits into two peaks. The first extinction peak is associated with the collective SPR mode of the monolayer and it shifts to shorter wavelengths as the spacer layer decreases. As the spacer layer decreases from 35 nm to 7.5 nm, the second peak gradually appears in the extinction spectra of the metasurface. We assign the second peak to the gap mode. The gap mode first appears at around 620 nm or greater and it shifts to larger wavelength for larger nanoparticle spacing and size. The FDTD simulations are confirmed by an experimental examination of the dispersion curves of a similar multilayer system. The computational results match the experimental results and confirm the excitation of the two modes.
关键词： gap plasmon mode,surface plasmon resonance,Plasmonic metasurfaces,aluminum thin film,FDTD,gold nanoparticles
更新于2025-11-19 16:56:42
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Rapid synthesis of AlON powders by low temperature solid-state reaction
摘要： High synthesis temperatures and long soaking times are generally required to fabricate AlON powders, which can cause coarsening and aggregation of the powder. Solid-state reaction methods form AlON powders by a direct reaction of Al2O3 and AlN, enabling rapid synthesis of AlON powder at low temperatures. In this work, single phase AlON powders were fabricated by a solid-state reaction method using Al2O3 and AlN powders as raw materials. To lower the synthesis temperature and shorten the soaking time, the raw materials particle sizes and the homogeneity of the Al2O3/AlN mixture were investigated. The effects of AlN content, synthesis temperature, and soaking time on the synthesis of AlON powders were examined. When the AlN content was 27 mol %, single phase AlON powders were synthesized by calcining Al2O3/AlN mixture at 1680 °C for 20 min. After ball-milling at 250 rpm for 24 h, the synthesized AlON powder was ground into a single phase fine AlON powder with an average particle diameter of 320 nm, a narrow size distribution, and good dispersibility. Transparent AlON ceramics with dimensions of Φ100 mm × 1 mm were fabricated by pressureless sintering the produced fine AlON powder.
关键词： B.Grain size,Aluminum oxynitride,A. Powders: solid-state reaction
更新于2025-11-19 16:56:35
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Ellipsometric study on optical properties of hydrogen plasma-treated aluminum-doped ZnO thin film
摘要： Aluminum-doped zinc oxide (AZO) thin films were prepared by radio frequency (RF) sputtering at room temperature, and then post-treated by hydrogen (H2) plasma at different durations. After H2 plasma treatment under the condition of 10 W, 200 °C and 3.0 Hours, the resistivity showed a dramatically decrease from 1.6 Ω cm to 3.4 × 10?3 Ω cm, while the transmittance at the wavelength of 550 nm was improved from 90.5% to 96.0%. The optical constants of H2 plasma-treated AZO thin films were detailed characterized by a varied angle spectroscopic ellipsometer. The results show that the refractive index n decreases in the entire measured wavelength range of 350–1100 nm, while the extinction coefficient k decreases in the short wavelength range and changes negligibly at the long wavelength range. These results can provide guidelines for the design and optimization of AZO thin film-based optoelectronic applications.
关键词： Resistivity,Spectroscopic ellipsometer,Transmittance,Optical constants,Hydrogen plasma treatment,Aluminum-doped zinc oxide
更新于2025-11-14 17:03:37
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Tunable optical and magnetic properties of Ni-doped CuSe nanowires using AAO template assisted hydraulic method
摘要： High uniformity of un-doped and Ni-doped CuSe nanowires have been fabricated through smelting the bulk and injecting the melted liquid into the anodic aluminum oxide (AAO) template. The Ni dopant concentration and morphology of CuSe nanowires can be well controlled via preparing the bulk materials and the channel size of AAO template. The cathodoluminescence (CL) peaks of the un-doped, 0.5 at% and 1.0 at% Ni-doped CuSe nanowires showed a redshift of about 26 nm and 42 nm from un-doped CuSe nanowires (579 nm), respectively. Furthermore, above room temperature ferromagnetism was observed in 1.0 at% Ni-doped CuSe nanowires at 300 K. The facile injection molding method fabricated nanowires with tunable optical and magnetic properties could be applied to prepare varied nanomaterials for spintronic devices in the further.
关键词： optical,anodic aluminum oxide (AAO),CuSe,doped,nanowires,magnetic
更新于2025-11-14 17:03:37