Unseen Possibilities of F‐Theta Lenses

Ozga, Cornelia

doi:10.1002/opph.201800015

Cited by 5 publications

(3 citation statements)

References 4 publications

(1 reference statement)

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“…[ 28,29 ] Four f‐ θ lenses (3) provided a planar focal level. [ 28,30 ] For each quadrant, a focused laser beam in an area of 250 × 250 mm 2 ( X – Y plane) can be guaranteed. [ 29 ] The laser beam focus was measured for each quadrant by the original equipment manufacturer as per standard service according to its specification.…”

Section: Methodsmentioning

confidence: 99%

Investigation on Process Stability and Part Positioning Influence on the Relative Density of Designed Materials via Laser‐Based Powder Bed Fusion of Metals on a Multi‐Laser Machine

et al. 2021

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Component production via laser‐based powder bed fusion of metals (PBF‐LB/M) is becoming reality for multiple applications. Especially for sophisticated parts, as in case of gas turbines, assurance of repeatable properties involves control of process and machine parameters. PBF‐LB/M is used to build configurable open‐porous structures—designed materials (DMs)—out of the high temperature superalloy Haynes 282 with relative densities from 35 % to 65 % . The objective is investigating positioning influence and process stability based on their relative densities in discrete scan fields and build jobs. As DMs made from Haynes 282 are not yet scientifically investigated, first the process boundaries are identified. The used PBF‐LB/M machine—EOS M 400‐4—works with four lasers in four quadrants—a quadrant benchmarking is carried out. The experiment is repeated in a second build job. Scatter is identified in quadrant and build job benchmarking. A further aspect under investigation is positioning within laser quadrants. However, keeping laser and parameter combinations constant, sample locations are assessed. A relative density dependency on the laser deflection angle—as a positional measure—is observed. The results of positioning influence and scatter are used to formulate a tolerance equation for relative densities of DMs.

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Section: Methodsmentioning

confidence: 99%

Investigation on Process Stability and Part Positioning Influence on the Relative Density of Designed Materials via Laser‐Based Powder Bed Fusion of Metals on a Multi‐Laser Machine

et al. 2021

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“…[ 32,33 ] In each case radiated f ‐ θ lenses (3) ensure a planar focal level. [ 32–34 ] Per original equipment manufacturer standard service the laser beam focus was calibrated for the individual quadrants. Specimens of a quadrant were only manufactured in the distinguished quarter, avoiding the overlap area and the area for build platform fixture (4).…”

Section: Methodsmentioning

confidence: 99%

Influence of Process Stability and Part Positioning on Morphological Properties of Designed Materials Produced by Laser‐Based Powder Bed Fusion of Metals on a Multi‐Laser Machine

et al. 2022

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Porous structures made from high temperature superalloys are candidates for high‐efficiency cooling applications. In this kind of product, the repeatability of flow‐relevant elements is of high interest in multiple aspects—e.g., performance, component lifetime, and costs. Configurable open‐porous materials—addressed here as designed materials (DMs)—can be produced via laser‐based powder bed fusion of metals (PBF‐LB/M) by process parameter adaptions. With the high temperature superalloy Haynes 282 DM's manufacturability was previously demonstrated on a multi‐laser EOS M 400‐4 PBF‐LB/M machine. The influence of part positioning on the respective relative density of such structures and scatter were shown and tolerance equations developed. Hence, herein, the main objective is following up on the repeatability of morphological DM properties. Therefore, DM's mean pore diameter, mean strut diameter, and surface ratio are analyzed via microcomputed tomography (μCT). A positional scatter assessment is performed. Moreover, attention is paid to the repeatability of the investigated properties over different laser quadrants and build jobs. The identified scatter is utilized in the tolerance equations formulated in this research. Furthermore, potential correlations among the properties—relative density, mean pore diameter, mean strut diameter, and surface ratio—are examined.

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“…This necessitates achieving planar imaging fields and ensuring consistent imaging performance throughout the scanning field. 56,57 Considering the widely used pre-objective scanning configuration, where the scanning unit is positioned in front of the focusing unit, 58 the objective typically consists of multiple lenses for a flat-field design. 58 Specifically, F-Theta lens designs are meticulously optimized to generate uniform focal shapes throughout the scanning field while minimizing field curvature.…”

Section: Large Scanning Field F-theta Lensmentioning

confidence: 99%

Optical tools for laser machining along six orders of magnitude

Hellstern,

Tillkorn,

Hieronymus

et al. 2024

High-Power Laser Materials Processing: Applications, Diagnostics, and Systems XIII

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We present an overview on the development and characterization of multiscale laser processing optics for versatile material modifications across more than six orders of magnitude. Starting with solutions for micromachining we present high-NA microscope objectives creating sub-wavelength material modifications on macroscopic scales with highest peak intensities. Moving on to the millimeter range, the adaptability and scalability of scanning optics is examined for large-area machining. Finally, we explore line beam optics in the meter range, evaluating their use in uniform material processing using average powers above 100 kW. This study provides an insight into the design and performance characteristics of such optics and demonstrates their potential in advanced laser processing.

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Unseen Possibilities of F‐Theta Lenses

Cited by 5 publications

References 4 publications

Investigation on Process Stability and Part Positioning Influence on the Relative Density of Designed Materials via Laser‐Based Powder Bed Fusion of Metals on a Multi‐Laser Machine

Investigation on Process Stability and Part Positioning Influence on the Relative Density of Designed Materials via Laser‐Based Powder Bed Fusion of Metals on a Multi‐Laser Machine

Influence of Process Stability and Part Positioning on Morphological Properties of Designed Materials Produced by Laser‐Based Powder Bed Fusion of Metals on a Multi‐Laser Machine

Optical tools for laser machining along six orders of magnitude

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