Abstract: Methods for determining the quality of a weld of a workpiece welded by laser-beam welding, wherein at least a partial region of a molten pool and/or of a surrounding area of the molten pool is observed by means of a measuring system during the laser-beam welding and the quality of the weld of the welded workpiece is determined on the basis of the observation result. At least one characteristic value that correlates with molten pool oscillation of the molten pool is observed during the laser-beam welding and a measure of an amplitude of the molten pool oscillation and/or a measure of a frequency of the molten pool oscillation is determined from the observed time curve of the characteristic value. A probability and/or a frequency for the occurrence of hot cracks at the weld of the workpiece is inferred.

Abstract: This disclosure describes laser machining head gas nozzles that have an exit opening for passage of a laser beam onto a workpiece; an annular gap surrounding the exit opening; and a sleeve disposed and guided displaceably within the annular gap for axial displacement between a rearward and a forward position. The sleeve projects beyond the exit opening at least in the forward position, and the sleeve is tiltably mounted in the annular gap.

Abstract: The present disclosure relates to methods and systems for monitoring a welding process for welding at least one glass workpiece to another workpiece, e.g., also made of glass, wherein a weld seam is formed in the workpieces in a process zone that is exposed to a pulsed processing beam, e.g., to a pulsed laser beam, such as an ultra-short-pulse laser beam, wherein the radiation emitted by the process zone is detected in a time-resolved manner.

Abstract: The present disclosure relates to methods and devices for monitoring a welding process for welding at least one glass workpiece to another workpiece, the workpieces being welded together in a process zone that is exposed to a processing beam, e.g., to a laser beam, such as an ultra-short-pulse laser beam, wherein radiation emitted by the process zone and originating from at least one of the workpieces is detected in a spatially resolved manner.

Abstract: Laser beam welding a workpiece includes: generating first and second beam areas on the workpiece by first and second laser beams, respectively. The beam areas are guided in a feed direction relative to the workpiece. Centroids of the beam areas are not coinciding. The first beam area runs ahead of the second beam area. A length of the first beam area, measured transversely to the feed direction, is greater than or equal to that of the second. A surface area of the first beam area is greater than that of the second. A width of the first beam area, measured in the feed direction, is greater than or equal to that of the second. A laser power of the first laser beam is greater than that of the second. The second laser beam is irradiated into a weld pool generated by the first laser beam.

Abstract: This disclosure describes laser machining head gas nozzles that have an exit opening for passage of a laser beam onto a workpiece; an annular gap surrounding the exit opening; and a sleeve disposed and guided displaceably within the annular gap for axial displacement between a rearward and a forward position. The sleeve projects beyond the exit opening at least in the forward position, and the sleeve is tiltably mounted in the annular gap.

Abstract: An example device for monitoring and controlling a laser cutting process on a workpiece includes an image capturing apparatus for capturing an image of a region of the workpiece to be monitored, in which the region of the workpiece to be monitored includes a region of interaction of a laser beam with the workpiece, and an evaluation apparatus for detecting material boundaries of the workpiece using the captured image. The evaluation apparatus is configured to determine at least one characteristic value of the laser cutting process based on a geometric relationship between at least two of the detected material boundaries, the region of interaction, or combinations thereof.

Abstract: This disclosure describes laser machining head gas nozzles that have an exit opening for passage of a laser beam onto a workpiece; an annular gap surrounding the exit opening; and a sleeve disposed and guided displaceably within the annular gap for axial displacement between a rearward and a forward position. The sleeve projects beyond the exit opening at least in the forward position, and the sleeve is tiltably mounted in the annular gap.

Abstract: This disclosure describes laser machining head gas nozzles that have an exit opening for passage of a laser beam onto a workpiece; an annular gap surrounding the exit opening; and a sleeve disposed and guided displaceably within the annular gap for axial displacement between a rearward and a forward position. The sleeve projects beyond the exit opening at least in the forward position, and the sleeve is tiltably mounted in the annular gap.

Abstract: This disclosure describes laser machining head cutting gas nozzles that include an inner nozzle having a nozzle opening configured to form a core gas flow, an outer nozzle having an annular gap surrounding the nozzle opening and configured to form an annular gas flow, and a sleeve in the annular gap, wherein the sleeve is arranged to be axially displaceable between a rearward position and a forward position, wherein the sleeve projects beyond the inner nozzle at least when in the forward position, and wherein the sleeve widens a cross-sectional area of the outer nozzle to a variable degree as the sleeve is displaced from the rearward to the forward position. Methods of using a cutting gas nozzle are also described.

Abstract: This disclosure describes laser machining head cutting gas nozzles that include an inner nozzle having a nozzle opening configured to form a core gas flow, an outer nozzle having an annular gap surrounding the nozzle opening and configured to form an annular gas flow, and a sleeve in the annular gap, wherein the sleeve is arranged to be axially displaceable between a rearward position and a forward position, wherein the sleeve projects beyond the inner nozzle at least when in the forward position, and wherein the sleeve widens a cross-sectional area of the outer nozzle to a variable degree as the sleeve is displaced from the rearward to the forward position. Methods of using a cutting gas nozzle are also described.

Abstract: A laser cutting machine for cutting a workpiece having a first thickness (using a first processing laser beam having a first laser beam characteristic and a workpiece having a different second thickness using at least a second processing laser beam having a different second laser beam characteristic includes a laser source for producing a unprocessed laser beam having a laser wavelength of less than 4 ?m, a device which forms from the unprocessed laser beam the processing laser beams, and a control unit which controls the device in dependence on the thickness of the workpiece to be cut.

Abstract: A laser cutting machine for cutting a workpiece having a first thickness (using a first processing laser beam having a first laser beam characteristic and a workpiece having a different second thickness using at least a second processing laser beam having a different second laser beam characteristic includes a laser source for producing a unprocessed laser beam having a laser wavelength of less than 4 ?m, a device which forms from the unprocessed laser beam the processing laser beams, and a control unit which controls the device in dependence on the thickness of the workpiece to be cut.

Abstract: The disclosure relates to methods and apparatuses for controlling a cutting process in which a workpiece is cut by a high-energy beam. A process light signal is detected emanating from an interaction region of the high-energy beam with the workpiece in a first wavelength range (??1), in which at least one metallic constituent (Fe, Cr) of the workpiece has at least one emission line, and in a second wavelength range (??2), which differs from the first wavelength range, in which continuum radiation of the workpiece without emission lines is detectable. Vaporization of the at least one metallic constituent (Fe, Cr) is monitored on the basis of an intensity of the process light signal detected in the first wavelength range (??1) and on the basis of an intensity of the process light signal detected in the second wavelength range (??2).

Abstract: Methods for determining the quality of a weld of a workpiece welded by laser-beam welding, wherein at least a partial region of a molten pool and/or of a surrounding area of the molten pool is observed by means of a measuring system during the laser-beam welding and the quality of the weld of the welded workpiece is determined on the basis of the observation result. At least one characteristic value that correlates with molten pool oscillation of the molten pool is observed during the laser-beam welding and a measure of an amplitude of the molten pool oscillation and/or a measure of a frequency of the molten pool oscillation is determined from the observed time curve of the characteristic value. A probability and/or a frequency for the occurrence of hot cracks at the weld of the workpiece is inferred.

Abstract: The present disclosure relates to a device for monitoring and for controlling a laser cutting process on a workpiece, and a method of using the same. The device includes an image capturing apparatus for capturing an image of a region of the workpiece to be monitored, in which the region of the workpiece to be monitored includes a region of interaction of a laser beam with the workpiece, and an evaluation apparatus for detecting material boundaries of the workpiece using the captured image. The evaluation apparatus is configured to determine at least one characteristic value of the laser cutting process based on a geometric relationship between at least two of the detected material boundaries, the region of interaction, or combinations thereof.

Abstract: This disclosure relates to methods and apparatuses for determining a material type and/or a surface condition of a workpiece. A surface of the workpiece is illuminated with illuminating radiation. At least one image of the illuminated surface is recorded. The material type and/or the surface condition of the workpiece is determined on the basis of a statistical analysis of the at least one image converted into a spatial frequency domain.

Abstract: The present disclosure relates to a device for monitoring and for controlling a laser cutting process on a workpiece, and a method of using the same. The device includes an image capturing apparatus for capturing an image of a region of the workpiece to be monitored, in which the region of the workpiece to be monitored includes a region of interaction of a laser beam with the workpiece, and an evaluation apparatus for detecting material boundaries of the workpiece using the captured image. The evaluation apparatus is configured to determine at least one characteristic value of the laser cutting process based on a geometric relationship between at least two of the detected material boundaries, the region of interaction, or combinations thereof.

Abstract: This disclosure describes laser machining head cutting gas nozzles that include an inner nozzle having a nozzle opening configured to form a core gas flow, an outer nozzle having an annular gap surrounding the nozzle opening and configured to form an annular gas flow, and a sleeve in the annular gap, wherein the sleeve is arranged to be axially displaceable between a rearward position and a forward position, wherein the sleeve projects beyond the inner nozzle at least when in the forward position, and wherein the sleeve widens a cross-sectional area of the outer nozzle to a variable degree as the sleeve is displaced from the rearward to the forward position. Methods of using a cutting gas nozzle are also described.

Abstract: This disclosure describes laser machining head gas nozzles that have an exit opening for passage of a laser beam onto a workpiece; an annular gap surrounding the exit opening; and a sleeve disposed and guided displaceably within the annular gap for axial displacement between a rearward and a forward position. The sleeve projects beyond the exit opening at least in the forward position, and the sleeve is tiltably mounted in the annular gap.