Blz Bayerisches Laserzentrum GmbH

Erlangen, Germany

Blz Bayerisches Laserzentrum GmbH

Erlangen, Germany
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Devrient M.,Blz Bayerisches Laserzentrum GmbH | Knoll B.,LPKF Laser and Electronics AG | Geiger R.,LPKF Laser and Electronics AG
Physics Procedia | Year: 2013

Beside well chosen process parameters a geometrical joining partner design suitable for laser transmission welding and adequate clamping pressure appliance is necessary to form high quality welds. Amongst other clamping techniques Dual Clamping Devices (DCD) are a promising approach to fulfill the process needs and to get to a robust and also fail safe clamping. When using DCD the laser beam has to pass thin non transmitting bars while a weld seam is formed. So the laser beam is partial refracted, reflected and absorbed. Here the influences of the bars onto the laser beam intensity distribution behind the bars rather in the interaction zone of the laser beam and the two joining partners are investigated. Welding experiments with DCD are carried out and discussed. Based on the experimental results thermal process simulations are performed, to get a deeper knowledge about the effect of the bars onto the spatially and temporally changing temperature field within the joining partners. © 2013 The Authors.


Haug P.,TRUMPF Laser und Systemtechnik GmbH | Rominger V.,TRUMPF Laser und Systemtechnik GmbH | Speker N.,TRUMPF Laser und Systemtechnik GmbH | Weber R.,University of Stuttgart | And 3 more authors.
Physics Procedia | Year: 2013

CO2- and solid-state lasers are the most widely used beam sources. Owing to their different physical beam characteristics, these two types of laser differ fundamentally not only in how the beam is guided but also in their process behavior during deep penetration welding. Almost all industrial applications in thick material > 8 mm have to be full penetration welds to increase fatigue strength, for example in ship building, pipeline construction, train and rail construction or power-train, Holzer et al., 2011. Therefore process behavior and limits at full penetration will be analyzed in detail for both beam sources. © 2013 The Authors.


Klocke F.,RWTH Aachen | Klink A.,RWTH Aachen | Veselovac D.,RWTH Aachen | Aspinwall D.K.,University of Birmingham | And 5 more authors.
CIRP Annals - Manufacturing Technology | Year: 2014

This paper presents an overview of the current technological and economical capabilities of electrochemical (ECM-based), electro-physical (EDM-based) and photonic (Laser-/EBM-based) additive and removal processes for turbomachinery component manufacture. Starting with the industrial demands and challenges of today, the technologies are reviewed in detail regarding achievable geometrical precision and surface integrity as well as material removal and deposition rates for conventionally difficult-to-cut Ti- and Ni-based alloys and dedicated steels. Past, existing and future areas of technology application of these advanced non-mechanical manufacturing processes are discussed. The paper focusses on the description of shaping processes therefore excludes pure welding or coating applications. © 2014 CIRP.


Schmidt M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schmidt M.,Blz Bayerisches Laserzentrum GmbH | Kolleck R.,University of Graz | Grimm A.,Blz Bayerisches Laserzentrum GmbH | And 2 more authors.
CIRP Annals - Manufacturing Technology | Year: 2010

Direct laser deposition offers a widespread spectrum of applications. Creating functional surfaces for forming tools is one of them where inexpensive material for the main tool body is complemented layer by layer with a second material to tune the desired properties and shape. Investigations on coating mild tool steel with copper alloy have been carried out to outline the chances and challenges in this cost effective way of producing forming tools for processing stainless steels, e.g. 1.4301. This paper reports on experimental investigations showing the influence of the absolute angle of the tool surface and the relative angle between surface and laser beam/powder nozzle on the process window and the mechanical properties that can be obtained. © 2010 CIRP.


Devrient M.,Blz Bayerisches Laserzentrum GmbH | Kern M.,Laser Zentrum Hannover e.V. | Jaeschke P.,Laser Zentrum Hannover e.V. | Stute U.,Laser Zentrum Hannover e.V. | And 3 more authors.
Physics Procedia | Year: 2013

Laser transmission welding is known for high flexibility, extraordinary potential for process automation and outstanding weld seam properties. Problems may occur due to the poor gap-bridging capability of contour welding. Gaps of a few tens of microns can lead to processing issues such as welding failures, poor achievable process speed or low weld seam strengths. To overcome this, laser transmission welding with part-adapted temperature fields was developed, and is experimentally investigated here. Results concerning the process behavior, dependent on several oscillation types of the laser beam, as well as achieved tensile shear strengths and the monitored gap-bridging capability are presented. © 2013 The Authors.


Leitz K.-H.,Friedrich - Alexander - University, Erlangen - Nuremberg | Quentin U.,Friedrich - Alexander - University, Erlangen - Nuremberg | Alexeev I.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schmidt M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schmidt M.,Blz Bayerisches Laserzentrum GmbH
CIRP Annals - Manufacturing Technology | Year: 2012

In a wide range of technological and biomedical applications nanostructured surfaces become increasingly important. Laser based techniques utilizing near-field focusing of pulsed laser radiation by microsphere particles allow a robust, low-cost nanopatterning at sub-diffraction-limited resolution. In combination with optical tweezers a direct-write nanostructuring becomes feasible. In this contribution, a fundamental simulational study of optical trap assisted ultrafast direct-write near-field nanostructuring showing the influence of the main process parameters is presented. © 2012 CIRP.


Amend P.,Blz Bayerisches Laserzentrum GmbH | Mohr C.,Blz Bayerisches Laserzentrum GmbH | Roth S.,Blz Bayerisches Laserzentrum GmbH | Roth S.,Friedrich - Alexander - University, Erlangen - Nuremberg
Physics Procedia | Year: 2014

In recent years, the joining of plastics and metals for lightweight constructions has become more and more important for industrial applications. This paper presents experimental investigations of transmission joining of polyamide aluminum hybrids using a combination of mono- and polychromatic radiation. The used experimental setup consists of a diode laser, a laser processing head with additional infrared emitters, a robot and a clamping device for lap joints. With this setup, experiments are performed to determine a process window for the thermal joining of polyamide aluminum hybrids and to evaluate geometrical, material-related and process-related limits of the approach. For that, hybrid joints of aluminum with sheet thicknesses of 0.6 mm to 1.0 mm and 3 mm thick unfilled polyamide 6 are used. To improve the mechanical interlocking between the polyamide and the aluminum surface a prior laser structuring of the metal is done by a ns-Nd:YAG-laser. Primarily, the influence of surface roughness and surface enlargement on the optical properties of aluminum and the mechanical properties of the joined specimens is investigated. © 2014 The Authors. Published by Elsevier B.V.


Stichel T.,Blz Bayerisches Laserzentrum GmbH | Laumer T.,Blz Bayerisches Laserzentrum GmbH | Baumuller T.,Friedrich - Alexander - University, Erlangen - Nuremberg | Amend P.,Blz Bayerisches Laserzentrum GmbH | Roth S.,Blz Bayerisches Laserzentrum GmbH
Physics Procedia | Year: 2014

In this report, the dry delivery of polyamide 12 powders by vibrating capillary steel nozzles is investigated and discussed regarding its potential for powder layer preparation in Laser Beam Melting. Therefore, a setup including a steel nozzle assembled on a piezoelectric actuator is presented, which enables the precise control over very small powder quantities by vibration excitation. An analysis reveals that the mass flow through the nozzle can be adjusted by the vibration modes in a certain range depending on the nozzle's specifications, whereas the vibration modes themselves show a complicated behaviour. Using a positioning system in combination with the vibrating nozzle, single-layer patterns consisting of polyamide 12 are produced and characterized regarding surface homogeneity and selectivity using a laser stripe sensor. © 2014 The Authors. Published by Elsevier B.V.


Tenner F.,Friedrich - Alexander - University, Erlangen - Nuremberg | Brock C.,Friedrich - Alexander - University, Erlangen - Nuremberg | Gurtler F.-J.,Friedrich - Alexander - University, Erlangen - Nuremberg | Klampfl F.,Friedrich - Alexander - University, Erlangen - Nuremberg | And 2 more authors.
Physics Procedia | Year: 2014

The keyhole is the crucial factor for an appropriate weld seam in laser metal welding. The stability of the keyhole is governed by multiple hydrodynamic effects such as melt flow, evaporation on the keyhole front, gas dynamics inside the evolving vapor plume and the resulting pressures from all these phenomena. Due to their elusive nature the measurement of pressures inside the keyhole is still an unresolved task. Here we show a quantification of the density of the metal vapor and the pressure inside the keyhole through measuring the keyhole opening geometry, the evaporation rate and the flow velocity inside the vapor plume. Furthermore, a comparison to a simulation model is shown. Our results are in accordance with theoretical approaches. In the future this results can support an increase of process understanding which eventually leads to a better control of the process in industry. © 2014 The Authors. Published by Elsevier B.V.


Hofmann K.,Blz Bayerisches Laserzentrum GmbH | Holzer M.,Blz Bayerisches Laserzentrum GmbH | Hugger F.,Blz Bayerisches Laserzentrum GmbH | Roth S.,Blz Bayerisches Laserzentrum GmbH | And 2 more authors.
Physics Procedia | Year: 2014

Investigations concerning the growth of intermetallic phases during the heat input both at the diffusion annealing of copper aluminum roll claddings and the subsequent welding process of copper-aluminum connections by using roll cladded inserts are compared to the analytical determination of phase growth. The temperature distribution in the cladding interface has been determined by thermal simulation, in order to calculate the growth of the intermetallic phases. A comparison between the width of the phases in the analytical calculation and the experiment is achieved. In consideration of high welding speeds, the energy input during the welding process is appraised in order to grade the growth of intermetallic phases. Furthermore the prevention of damage in the roll cladding interface by means of unadapted material thicknesses or welding parameters can be assessed analytically and numerically. The numerical simulations can determine the critical thickness of the roll cladding to avoid damage like exceeding growth of intermetallic phases. © 2014 The Authors. Published by Elsevier B.V.

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