Косвенные методы измерения неравномерности воздушного зазора асинхронных электродвигателей

As widely known laser materials processing has some advantages regarding local heat input and controllability. In many fields applications were developed which are not accessible for conventional thermal processing. In other fields laser-supported manufacturing techniques are a valuable alternative. On the one hand laser techniques enable increased processing speed and less post-processing, leading to an increased productivity. On the other hand low efficiencies in the energy conversion seem to be a major drawback and apparently limit the range of applications. In the frame of conventional processing schemes laser beam welding requires a high utilization in order to run economically. Main advantages lie in the reduced consumption of material and the reduced efforts in post processing. Because of the locally concentrated heat input process emissions are lower which reduces energy and material consumption in the auxiliary chain. To make full use of the often-conjured flex ibility a multitude of manufacturing schemes had been developed and adapted. In order to appraise the versatility of laser driven processing techniques a cost and benefit analysis based on a life-cycle approach is conducted including both, economics and ecology. Eco-efficiency is rated by a variation of the BASF method. Taking into account the reduced consumption of consumables, reduced effort for preparation and post-processing, and focusing on specific application ranges a positive environmental impact can be proven

Об анализе некоторых виброграмм

Laser materials processing is widely used in industry today. The quality of the produced parts is vital for the manufacturer and it is even more important to discover early in the manufacturing process if the required result can be met. ISO 9000 and other by law enforced regulations have led to the understanding that quality control is an essential tool in modern manufacturing and necessary in order to keep production results in deterministic boundaries. Even in the most modern laser based manufacturing systems in operation, few of the key process input parameters are monitored or recorded in any way. The acquisition of such data is usually limited to measuring the laser beam with respect to focal position and power. The online assessment of weld seam quality, both in applications with high penetration depths, as well as those used for the joining of flexible sheets (both metal and non-metals), is a key aspect of maintaining quality. In deep penetration welding of highl y stressed components, the consistency of producing defined or full penetration welds is highly desired. Current work in this area is based on the approach of using advanced monitoring strategies. This includes multiple sensing concepts where several independent parameters or features are observed simultaneously in one setup. Besides collecting information directly from the process also geometrical data like shape or size can be used to evaluate the produced quality. Moreover, spatially resolved measurement of temperature radiation yields to additional information. This contribution shows up the current state-of-research and will draw up the route how these lab based results can be used in industrial application in the near future

Mobile technologies in foreign language learning

Welding with laser beams is an innovative optical technique, which leads to higher penetration depth and a narrower seam compared to conventional welding techniques. Significant criteria of the quality of a junction besides detected faults are the penetration depth and the seam width. Within this article optical sensors for process monitoring as well as a predictive control scheme based on these are presented. In the closed loop control the process' inputs laser power and focal position are optimised by taking the future welding speed into account. For modelling the physical demanding, non-linear process an Artificial Neural Network with external dynamics is applied. First results of the application on a real laser welding system are described

Моделирование реакционно-ректификационной колонны синтеза этил-трет-бутилового эфира (ЭТБЭ)

Die vorliegende fünfteilige Artikelserie beschreibt Konzepte und Anwendungen der Lasertechnik in der Fertigung. Aufbauend auf einer Erhebung des Anwendungspotentials werden Aspekte der Anlagen- und Prozessplanung sowie zugeschnittene Fertigungskonzepte diskutiert. Hieraus wird eine integrierte Vorgehensweise zur Einbindung in Systeme für die Qualitätssicherung und der Arbeitssicherheit abgeleitet

Laser-based powder bed fusion of Ti-6Al-4V structures with different surface-area-to-volume ratios in oxygen-reduced and oxygen-free environment

Titanium alloys, such as Ti-6Al-4V, are particularly susceptible to oxidation, which is why their processing in the laser-based powder bed fusion process is carried out conventionally in a protective gas atmosphere. However, this atmosphere still contains critical residual oxygen levels, which are to be eliminated as part of a new approach. This approach envisages doping the argon protective gas atmosphere with small amounts of the highly reactive gas silane (ratio < 1:1000). The residual oxygen content is particularly critical in filigree and thin-walled structures that have a high surface-area-to-volume ratio and are a typical field of application for this additive manufacturing process. Therefore, this work focuses on the manufacturing of Ti-6Al-4V structures with different surface-area-to-volume ratios in conventional argon (< 200 ppm residual oxygen) and argon-silane atmospheres (< 10-14 ppm residual oxygen) on an innovative laboratory machine. After processing, the specimens are analyzed for surface topography, microstructure, and Vickers hardness. In addition, energy-dispersive X-ray spectroscopy and X-ray diffraction measurements are carried out to further investigate the chemical composition and present phases in the as-built specimens. The influence of the different atmospheres and their residual oxygen content, the surface-to-volume ratio, and possible interactions between them are discussed

Thermoforming of planar polymer optical waveguides for integrated optics in smart packaging materials

The innovations in smart packaging will open up a wide range of opportunities in the future. This work describes the processing of additive manufactured and planar integrated polymer optical waveguides for use in smart packaging products. The previously published combination of flexographic and Aerosol Jet printing is complemented by thermoforming and thus creates three-dimensional integrated multimode waveguides with optical attenuation of 1.9 dB/cm ± 0.1 dB/cm @ 638 nm. These properties will be the basis to develop smart applications in packaging materials

Robot based remote laser cutting of three-dimensional automotive composite parts with thicknesses up to 5mm

With the intention to develop a robot based laser cutting process for automotive 3D parts with varying thickness consisting of carbon fibre reinforced plastics (CFRP), strategies of 2D investigations were adapted. The used setup consist of a fibre guided nanosecond pulsed laser with an average power of P L = 1.5 kW, a 6-axis robot and a 3D programmable focusing optic (I-PFO). In a first instance strategies for the remote cutting of material with a thickness of d = 5 mm were developed and optimized concerning cutting efficiency and quality. In a second step the results were transferred to a robot based 3D cutting process. Main challenges are the consideration of the correct angle of incidence, the geometric constancy and the accessibility of the cutting geometry by the I-PFO for complex shaped 3D parts. Therewith, “cutting-on-the-fly” strategies were realized for automated trimming and drilling of large automotive structures

Functional coatings of sol-gel on glass substrate using CO2 laser irradiation

Often Glass products achieve their component functionality only by a specific surface finishing, such as coating or patterning. Compared to vacuum based CVD and PVD coating techniques, the equipment for wet-chemical deposition of sol-gels is less expensive. Heat is needed for a chemical reaction to cure gels and form solid functional layers. In this study, sols with titanium and zirconium were applied on glass substrates by dip coating. The investigated layer thicknesses were in the range between 320 nm and 650 nm. The gel layers were annealed with CO2 laser radiation. Different scanning speeds and laser powers were investigated. Microscope images were used to compare the laser-annealed layers with oven-annealed layers. To conclude, the oven-process can be substituted by laser annealing and additionally enables local patterning. This allows gradient coating solutions for architecture applications