Abstract: A method for producing a control signal for positioning a holder of a solid freeform fabrication device that is height-adjustable relative to a working surface, comprising arranging a structural platform on the holder; capturing a plurality of images of the working surface in the region of the holder, an image-specific height of the holder being adjusted before the detection of one of the plurality of images, and depending on the change of direction in the height, a powder layer is applied or removed; determining a powder boundary line between a powder-free region and a powder-covered region of the structural platform for at least two of the plurality of images, captured for differently adjusted image-specific heights of the holder, and producing a control signal for positioning the holder on the basis of the at least two powder boundary lines. The holder can be aligned according to the control signal.

Abstract: This disclosure provides collector elements for gas circuits of additive manufacturing systems for making 3D components from a powder. The collector elements include an intake duct portion having a strip-shaped inflow duct with an intake opening and a main body portion that includes a cylindrical cavity extending along the intake duct portion, the cavity being fluidly connected to the inflow duct with a step in the rounded wall that causes an increase in diameter from a first diameter of the cavity to a second, larger diameter. The collector element also includes a first gas discharging portion with a tube portion and a diameter adjusting portion that fluidly connects a first end of the cavity to the inner volume of the tube portion via a duct.

Abstract: A laser beam directed is moved relative to a workpiece to weld along a weld seam and form a weld pool in the area surrounding the laser beam. The weld pool has a characteristic oscillation frequency fco, and a laser power is modulated with a modulation frequency f and a modulation amplitude ?=1?Pmin/Pmax, where Pmin is minimal and Pmax is maximal laser power during a modulation period. For a normalized characteristic oscillation frequency ?co and a normalized modulation frequency ?, ??2.2*?co, with ?=f·df/?, where ? is the feed rate of the laser beam, and df is diameter of a beam focal spot. Also, ?co=f,cotest·df,cotest/vcotest, where fcotest is a measured characteristic oscillation frequency, df,cotest the diameter of the beam focal spot, and vcotest is the feed rate of laser beam, all during a test measurement without modulation of the laser power.

Abstract: An irradiating device for irradiating a machining field with a machining beam, in particular with a laser beam, for carrying out a welding process, is provided. The irradiating device includes a beam scanner for aligning the machining beam to a machining position in the machining field. The irradiating device has an imaging device for imaging a part-region of the machining field on a pyrometer which has at least two pyrometer segments. The imaging device images thermal radiation which emanates from the machining position in the machining field on a first pyrometer segment, and images thermal radiation which emanates from a position in the machining field being situated ahead of or behind the machining position along an advancing direction of the machining beam in the machining field on at least one second pyrometer segment. A machine tool having such an irradiating device is also provided.

Abstract: A plate-like workpiece having a transparent, glass, glass-like, ceramic and/or crystalline layer, such as for use in an electronic display screen, is processed into separate segments by first incompletely severing the workpiece along outer contours of bounded segments, by forming holes through the layer with a laser beam, leaving the segments interconnected at narrow connections, and then separating the segments by severing the web-like connections.

Abstract: For material processing of a material, which is in particular for a laser beam to a large extent transparent, asymmetric shaped modifications are created transverse to the propagation direction of the laser beam. Thereby, the laser beam is shaped for forming an elongated focus zone in the material, wherein the focus zone is such that it includes at least one intensity maximum, which is transverse flattened in a flattening direction, or a transverse and/or axial sequence of asymmetric intensity maxima, which are flattened in a sequence direction. After positioning the focus zone in the material, a modification is created and the material and the focus zone are moved relative to each other in the or across to the flattening direction or in the or across to the sequence direction for forming a crack along an induced preferred direction.

Abstract: In an example method, a laser processing head is moved from an entrance region over a workpiece to a starting position above the workpiece. During this time, a distance control system is used to control the distance between the laser processing head and the workpiece based on measurements obtained from one or more distance sensors. Further, the laser processing head is moved from the starting position to a position beyond an edge of the workpiece. During this time, the distance control system is disengaged. When the laser processing head reaches the position beyond an edge of the workpiece, laser emission is initiated, and the laser processing head is moved back towards the starting position. Upon reaching the starting position, the distance control system is reengaged. The laser processing head is subsequently moved along a pre-determined path to cut the workpiece.

Abstract: Methods, machines, and computer-readable mediums for determining distance correction values of a desired distance between a laser processing nozzle on a laser processing head and a workpiece during laser processing of the workpiece are provided. In some implementations, the workpiece is scanned along a desired path of a surface of the workpiece separately by the laser processing nozzle and a measurement head arranged in place of the laser processing nozzle on the laser processing head, with a capacitively measured distance identical to the desired distance. The measurement head has a lower lateral sensitivity of a capacitance measurement than the laser processing nozzle. Respective scanned movement paths of the laser processing nozzle and the measurement head are determined. The distance correction values for the desired distance of the laser processing nozzle are then determined from the scanned movement paths determined with the laser processing nozzle and the measurement head.

Abstract: The present disclosure relates to a method for determining a beam profile of a laser beam, which is positioned by a scanner device in a processing field. The method includes: arranging at least one retroreflector in the processing field for irradiating powder layers of the scanner device; detecting laser radiation reflected back into the scanner device while the laser beam is scanned over the retroreflector; and determining the beam profile of the laser beam by using the laser radiation detected during the scanning travel over the retroreflector.

Abstract: A laser machining head includes a focusing optical unit for focusing a laser beam in a direction of a machining zone of a workpiece and includes a cross-jet nozzle for producing a cross flow that passes through the focused laser beam transversely (e.g., at a right angle to) a beam axis of the focused laser beam. The distance of the cross-jet nozzle from the workpiece is less than 20 mm (e.g., between 8 mm and 12 mm). A nozzle body having a bottom opening that faces downward toward the workpiece is provided laterally adjacent to the focused laser beam. A protective gas flows out of the bottom opening, which is arranged below the cross-jet nozzle in order to entrain the protective gas flowing between the nozzle body and the workpiece due to the cross flow of the cross-jet nozzle so that the protective gas flows over the machining zone.

Abstract: A diffractive optical beam shaping element for imposing a phase distribution on a laser beam that is intended for laser processing of a material includes a phase mask that is shaped as an area and is configured for imposing a plurality of beam shaping phase distributions on the laser beam incident on to the phase mask. A virtual optical image is attributed to at least one of the plurality of beam shaping phase distributions, wherein the virtual image can be imaged into an elongated focus zone for creating a modification in the material to be processed. Multiple such elongated focus zones can spatially add up and interfere with each other, to modify an intensity distribution in the material and, for example, generate an asymmetric modification zone.

Abstract: A method for machine processing, in particular for machine welding processing of workpieces, in particular of plate-like workpieces, tubes and/or profiles, by means of a thermal processing beam, in particular by means of a processing beam is described, wherein the processing of the workpiece is carried out with a relative movement between the processing beam and the workpiece, wherein a process gas is fed to a processing zone in a settable quantity of process gas per unit of time. After a stored stabilization time, in which the processing of a workpiece is continued with a relative movement between the processing beam and the workpiece, a quantity of process gas per unit of time is automatically reduced. Further a control apparatus of a setting device for process gas feed according to such a method is described.

Abstract: An impedance matching circuit for a gas-laser excitation system includes a high-frequency connection line configured to be connected at a first connection point to a power source and at a second connection point to a gas-laser electrode. The impedance matching circuit is characterized in that an impedance of at least one section of the high-frequency connection line changes by a change to a configuration of the high-frequency connection line, in particular to at least one parameter of the high-frequency connection line in the at least one section.

Abstract: The invention concerns a method for generating a laser beam (3) with different beam profile characteristics, whereby a laser beam (2) is coupled into one fiber end (1a) of a multi-clad fiber (1), in particular a double-clad fiber, and emitted from the other fiber end (1b) of the multi-clad fiber (1) and whereby, to generate different beam profile characteristics of the output laser beam (3), the input laser beam (2) is electively coupled either at least into the inner fiber core (4) of the multi-clad fiber (1) or at least into at least one outer ring core (6) of the multi-clad fiber (1), as well as a corresponding arrangement (10).

Abstract: In a machine tool, in particular a laser machine tool, a workpiece slide or tool slide is movable along a guide rail and has at least two guide carriages that are guided on the guide rail. The machine tool has a covering hood that is moved along with the slide, for covering that rail section of the guide rail that is located between the two guide carriages. The covering hood is a part that is not connected to the slide. The covering hood is guided on the guide rail in a displaceable manner between the two guide carriages and is entrained in the displacement direction by the rear guide carriage when the slide is displaced.

Abstract: Methods, devices and systems for laser decoating of coated metal sheets, in particular for removing a metal protective layer from a metal sheet by a laser beam. The laser beam is directed onto a surface of a metal sheet coated with a metal protective layer, such that the laser beam strikes the surface of the metal sheet at a laser spot and melts material of the metal protective layer. A gas is directed by a plurality of nozzles at a pressure of at least 3 bar and at an acute angle with respect to the laser beam onto the laser spot. The nozzles are arranged around the laser beam such that the gas directed from the nozzles blows away the melted material of the metal protective layer from the metal sheet.

Abstract: Implementations of the present disclosure include methods, systems, and computer-readable storage mediums for determining a deviation between an actual position and a desired position of a laser machining head of a laser machining machine. Implementations include actions of selecting at least two different machining positions of the laser machining head, in which a laser beam emitted by the laser machining head is directed onto a desired position of a workpiece, moving the laser machining head into a first selected machining position and forming a through-opening into the workpiece at or around the desired position by operation of the laser beam, moving the laser machining head into a second selected machining position and detecting radiation generated by an interaction between the laser beam and the workpiece, and determining whether there is a deviation between an actual position of the laser machining head and the desired position based on the detected radiation.

Abstract: A method for cutting off an edge portion of a workpiece includes applying a laser to the workpiece to form multiple individual severing cuts in the edge portion such that the edge portion is cut off from the workpiece, the multiple individual severing cuts being arranged together along the edge portion. Applying the laser to the workpiece to form the multiple individual severing cuts includes, for each individual severing cut, translating a laser cutting head and/or the workpiece relative to one another, and detecting, at an end of each severing cut, an edge of the workpiece, in which the translation of the laser cutting head or the workpiece continues at least until the edge is detected.

Abstract: A diffusion-cooled gas laser system that includes a first and a second electrode and a discharge gap arranged between the electrodes, wherein a dielectric is arranged on at least one of the electrodes on the discharge-gap side. The system is characterized in that the dielectric thickness d/?res the dielectric for influencing the discharge ?res of distribution in the discharge gap varies along at least one dimension of the electrode on which the dielectric is arranged, wherein d is the thickness of the dielectric, and ?res is the resultant constant of the dielectric, and, at its thickest point, has a thickness of at least 1 mm or is greater than one hundredth of the length of the electrode or is greater than one thousandth of a wavelength determined by the frequency of a radiofrequency electrical power to be coupled into the system.

Abstract: A method of processing structurally identical workpieces using a numerically controlled workpiece processing apparatus includes processing a first workpiece according to a first desired tool path specified for a tool of the numerically controlled workpiece processing apparatus by closed-loop controlling a working distance between the tool and the workpiece to achieve a defined desired distance, such that when processing the first workpiece, the tool is moved along a distance-controlled actual tool path. The method further includes optimizing the first desired tool path for a second workpiece based on the distance-controlled actual tool path of the first workpiece to provide a second desired tool path and processing the second workpiece according to the second desired tool path.