The Experts below are selected from a list of 31182 Experts worldwide ranked by ideXlab platform
Seiji Katayama - One of the best experts on this subject based on the ideXlab platform.
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Review of Laser Welding monitoring
Science and Technology of Welding and Joining, 2014Co-Authors: D. Y. You, X.-d. Gao, Seiji KatayamaAbstract:Laser Welding, as a highly efficient processing technology, has been widely applied to manufacturing industry. This paper makes an overview on real time monitoring of Laser Welding. It begins with a detailed introduction to six typical sensors (photodiode, visual, spectrometer, acoustical sensor, pyrometer, plasma charge sensor) in Laser Welding detection. Then it makes a review on multi-sensor fusion technology in both Laser Welding monitoring and adaptive control. Last, subjects for future research concerning Welding monitoring and control have been proposed. The paper concludes that the real-time monitoring of Laser Welding can provide a great amount of valid information about Welding status to help effectively identify weld defects and realize adaptive control.
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Introduction: Fundamentals of Laser Welding
Handbook of Laser Welding Technologies, 2013Co-Authors: Seiji KatayamaAbstract:This chapter describes characteristics of Laser Welding, features of main Lasers used for Welding, factors affecting weld penetration, Laser Welding phenomena including behavior of Laser-induced plume, keyhole behavior and melt flows in a molten pool during Laser Welding. It also refers to Welding defects and the recent trend for Laser Welding.
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handbook of Laser Welding technologies
2013Co-Authors: Seiji KatayamaAbstract:Part 1 Developments in established Laser Welding technologies: Introduction: Fundamentals of Laser Welding Developments in CO2 Laser Welding Developments in Nd:YAG Laser Welding Developments in disk Laser Welding Developments in pulsed and continuous wave Laser Welding technologies Conduction Laser Welding Developments in Laser micro Welding technology. Part 2 Laser Welding technologies for various materials: Laser Welding of light metal alloys: aluminium and titanium alloys Laser Welding and brazing of dissimilar metals Laser Welding of plastics Laser Welding of glass Defects formation mechanisms and preventive procedures in Laser Welding Residual stress and distortion in Laser Welding. Part 3 Developments in emerging Laser Welding technologies: Applications of robotics in Laser Welding Developments in beam scanning (remote) technologies and smart beam processing Developments in twin-beam Laser Welding technology Developments in multi-pass Laser Welding technology with filler wire Developments in hybridisation and combined Laser beam Welding technologies Developments in hybrid Laser-arc Welding technology Developments in modelling and simulation of Laser and hybrid Laser Welding. Part 4 Applications of Laser Welding: Applications of Laser Welding in the automotive industry Applications of Laser Welding in the railway industry Applications of Laser Welding in the shipbuilding industry.
J. Meijer - One of the best experts on this subject based on the ideXlab platform.
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Shedding Light on Laser Welding
2005Co-Authors: B.j. Aalderink, Ronald G.k.m. Aarts, Jan B. Jonker, J. MeijerAbstract:Nd:YAG Laser Welding is often used in industry to obtain high quality joints. This however does not mean that monitoring or control of this process is common practice. A few commercial products are available but none of these systems can be used for monitoring the Laser Welding process of aluminium. Within the NIMR project Multivariable melt pool control for double spot Laser Welding a monitoring system is developed based on a CMOS camera which is suited for the observation of Nd:YAG Laser Welding of various materials, including aluminium, under different conditions.
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Shedding Light on Laser Welding [poster]
2005Co-Authors: B.j. Aalderink, Ronald G.k.m. Aarts, Jan B. Jonker, J. MeijerAbstract:Nd:YAG Laser Welding is often used in industry to obtain high quality joints. This however does not mean that monitoring or control of this process is common practice. A few commercial products are available but none of these systems can be used for monitoring the Laser Welding process of aluminium. Within the NIMR project Multivariable melt pool control for double spot Laser Welding a monitoring system is developed based on a CMOS camera which is suited for the observation of Nd:YAG Laser Welding of various materials, including aluminium, under different conditions.
B.j. Aalderink - One of the best experts on this subject based on the ideXlab platform.
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Shedding Light on Laser Welding
2005Co-Authors: B.j. Aalderink, Ronald G.k.m. Aarts, Jan B. Jonker, J. MeijerAbstract:Nd:YAG Laser Welding is often used in industry to obtain high quality joints. This however does not mean that monitoring or control of this process is common practice. A few commercial products are available but none of these systems can be used for monitoring the Laser Welding process of aluminium. Within the NIMR project Multivariable melt pool control for double spot Laser Welding a monitoring system is developed based on a CMOS camera which is suited for the observation of Nd:YAG Laser Welding of various materials, including aluminium, under different conditions.
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Shedding Light on Laser Welding [poster]
2005Co-Authors: B.j. Aalderink, Ronald G.k.m. Aarts, Jan B. Jonker, J. MeijerAbstract:Nd:YAG Laser Welding is often used in industry to obtain high quality joints. This however does not mean that monitoring or control of this process is common practice. A few commercial products are available but none of these systems can be used for monitoring the Laser Welding process of aluminium. Within the NIMR project Multivariable melt pool control for double spot Laser Welding a monitoring system is developed based on a CMOS camera which is suited for the observation of Nd:YAG Laser Welding of various materials, including aluminium, under different conditions.
Koichi Niwa - One of the best experts on this subject based on the ideXlab platform.
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Laser Welding Copper and Copper Alloys
Journal of Laser Applications, 1991Co-Authors: Hashimoto Kaoru, Takehiko Sato, Koichi NiwaAbstract:We have developed a Laser hermetic sealing technique that combines nickel plating with Laser Welding for copper and copper alloy bellows for general purpose large‐scale computers. Laser Welding of copper has been difficult because of copper's high thermal conductivity and reflectivity. However, Laser Welding nickel‐plated copper results in deep penetration. To avoid corrosion induced at the dissimilar metal contact between nickel and copper, the nickel‐plated copper was heat‐treated before Welding to obtain a nickel‐copper solid solution. Then, the optimum plating thickness and heat‐treatment conditions were determined. A 10 μm‐thick nickel plating, heat‐treated for 1 h at 1000°C was found to be best suited to Laser Welding. These conditions make the Laser weld of copper and copper alloy strong. Tests indicate that this technique is suitable for Laser Welding copper and copper alloys.
Jian Xie - One of the best experts on this subject based on the ideXlab platform.
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Cracking prevention in Laser Welding of high-restraint joints
International Congress on Applications of Lasers & Electro-Optics, 2000Co-Authors: Jian XieAbstract:High power Lasers have been widely used to weld a variety of products in industries. One of the most popular applications is Laser Welding of transmission components in the automotive industry such as gear clusters, splines, couplings and clutches. However, they are high-restrained joint configurations and solidification cracking is one of the most-often encountered problems. Cracking prevention is a major concern in Laser Welding of such joint configurations. In this study, cracking mechanism in Laser Welding was reviewed and the methods to prevent cracks in Laser Welding of a high-restraint joint (gear to shaft) were investigated. Although several kinds of cracks were observed in the high-restraint welds such as centerline and transverse cracks, the cracks in the joints are solidification cracking in nature that occurred in the fusion zone near the end of solidification under tension stresses. To prevent the solidification cracking in Laser Welding of the high restraint gear/shaft joint, several joint designs and Welding methods were tested, including use of stress-relief grooves, pre-heating, optimization of Welding parameters, use of filler wires, discontinuous welds. The results indicated that proper joint designs could avoid solidification cracking effectively in Laser Welding of the high-restraint joint.High power Lasers have been widely used to weld a variety of products in industries. One of the most popular applications is Laser Welding of transmission components in the automotive industry such as gear clusters, splines, couplings and clutches. However, they are high-restrained joint configurations and solidification cracking is one of the most-often encountered problems. Cracking prevention is a major concern in Laser Welding of such joint configurations. In this study, cracking mechanism in Laser Welding was reviewed and the methods to prevent cracks in Laser Welding of a high-restraint joint (gear to shaft) were investigated. Although several kinds of cracks were observed in the high-restraint welds such as centerline and transverse cracks, the cracks in the joints are solidification cracking in nature that occurred in the fusion zone near the end of solidification under tension stresses. To prevent the solidification cracking in Laser Welding of the high restraint gear/shaft joint, several joint d...
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Plasma fluctuation and keyhole instability in Laser Welding
International Congress on Applications of Lasers & Electro-Optics, 1999Co-Authors: Jian XieAbstract:In high-power Laser Welding, a focused Laser beam melts and vaporizes the material to form a metal vapor above the surface of a workpiece. As the focused Laser beam continuously irradiates on the metal vapor, the Laser beam ionizes the metal vapor and a portion of the shielding gas forming a hot and opaque plasma plume. Previous studies showed that the plasma plume was unstable during Laser Welding and it influenced Laser energy utilization, process stability, and weld quality. In this study, dynamic behaviors of the plasma plume during Laser Welding were investigated using a high-speed camera at a speed of 9000 frames/second. It was found that the plasma grew in size continuously to a maximum height and then became small with respect to the elapsed time. The plasma fluctuated at an average frequency of 1.2 kHz in Laser Welding of steel. The plasma plume varied in dimensions dramatically in Laser Welding of aluminum and the average fluctuation frequency was about 1.3 kHz. The plasma fluctuation was related to the keyhole instability and this fluctuation was likely caused by the variation of the keyhole opening. Laser weld quality would be improved significantly if the keyhole instability or plasma fluctuation was suppressed during Laser Welding. One of the techniques of minimizing keyhole instability was the use of dual-beam Laser Welding technology. Experimental results indicated that the plasma plumes in dual-beam Laser Welding were stable and good-quality welds were produced for both steel and aluminum.In high-power Laser Welding, a focused Laser beam melts and vaporizes the material to form a metal vapor above the surface of a workpiece. As the focused Laser beam continuously irradiates on the metal vapor, the Laser beam ionizes the metal vapor and a portion of the shielding gas forming a hot and opaque plasma plume. Previous studies showed that the plasma plume was unstable during Laser Welding and it influenced Laser energy utilization, process stability, and weld quality. In this study, dynamic behaviors of the plasma plume during Laser Welding were investigated using a high-speed camera at a speed of 9000 frames/second. It was found that the plasma grew in size continuously to a maximum height and then became small with respect to the elapsed time. The plasma fluctuated at an average frequency of 1.2 kHz in Laser Welding of steel. The plasma plume varied in dimensions dramatically in Laser Welding of aluminum and the average fluctuation frequency was about 1.3 kHz. The plasma fluctuation was relate...
