A5062293502- Laser Material Processing Techniques
- Advanced machining processes and optimization
- Advanced Surface Polishing Techniques
- Welding Techniques and Residual Stresses
- Additive Manufacturing Materials and Processes
- Advanced Welding Techniques Analysis
- Metal and Thin Film Mechanics
- Advanced Machining and Optimization Techniques
- Tribology and Lubrication Engineering
- Laser-induced spectroscopy and plasma
- Diamond and Carbon-based Materials Research
- Adhesion, Friction, and Surface Interactions
- Laser Design and Applications
- Surface Treatment and Residual Stress
- Laser and Thermal Forming Techniques
- Tribology and Wear Analysis
- Aluminum Alloy Microstructure Properties
- Additive Manufacturing and 3D Printing Technologies
- Surface Modification and Superhydrophobicity
- Nanomaterials and Printing Technologies
- Metal Alloys Wear and Properties
- High Entropy Alloys Studies
- Laser-Ablation Synthesis of Nanoparticles
- High-Temperature Coating Behaviors
- Corrosion Behavior and Inhibition
Bremen Institute for Applied Beam Technology
2014-2025
University of Bremen
2021-2025
Argonne National Laboratory
2024
ARC Centre of Excellence for Children and Families over the Life Course
2022
The University of Queensland
2022
Optica
2021
Modifiable non-communicable disease (NCD) risk factors are becoming increasingly common among adolescents, with clustering of these in individuals particular concern. The aim this study was to assess global status modifiable NCD adolescents.We used latest available data from nationally representative survey for 140 countries, namely the Global School-based Student Health Survey, Behaviour School-Aged Children and longitudinal Australian Children. Weighted mean estimates prevalence...
Laser chemical machining (LCM) utilizes the thermal induced dissolution to remove material far below melting temperature. Material removal during LCM with modulated laser power depends on modulation frequency applied. The spatial of depth’s oscillation corresponds up threshold frequency. Above this threshold, depth remains constant. aim work is investigate whether could be used for surface structuring and its influence wetting behavior. Therefore, line scans different overlaps were generated...
Abstract Control of the melt pool size is necessary to achieve more homogenous material properties in wire arc additive manufacturing (WAAM). The can be measured by camera imaging or temperature field measurement. paper aims investigate feasibility using a high dynamic range two-colored pyrometric (Pyrocam) for measurement gas metal welding–based WAAM process. A set band-pass filters identified spectroscopy analysis reduce optical emission while remains visible. fusion line images, an...
Laser chemical machining (LCM) is a method of laser processing based on gentle material removal by means thermal induced dissolution. Since LCM depends predominantly the surface temperature workpiece, process window restricted appearance gas bubbles at higher powers and their associated shielding effect. In order to extend understanding, influence power modulation behavior investigated in present work. The experiments were conducted titanium grade 1 with phosphoric acid. Based response time...
During many manufacturing processes for surface treatment of steel components heat will be exchanged between the environment and workpiece. The exchange commonly leads to temperature gradients within near area workpiece, which involve mechanical strains inside material. If corresponding stresses exceed locally yield strength material residual can remain after process. increase is high enough additionally phase transformation austenite occurs may lead further on due a fast cooling very hard...
The zinc layer of zinc-coated steel is known to be a crucial factor for the spreading liquid aluminium on coated surface. For industrial brazing and welding processes these zinc-coatings enable fluxless joining between in many cases. Yet, reason beneficial effect wetting process not completely understood. Fundamental investigations behaviour single droplets different surfaces have revealed distinct difference at room temperature elevated regarding influence coating thicknesses. In this paper...
Surface layer properties are of crucial importance for the functional performance manufactured components. For vision a function-oriented production, relevant surface considered (e.g. fatigue strength, corrosion resistance) to be generated by an adequate selection and adjustment manufacturing processes. In order accomplish this in resource-efficient manner, extensive knowledge about impact processes on workpiece material is required. During process, responds external loads process forces,...
Material properties of metals and metal alloys at high temperatures are often unknown, but necessary to understand physical mechanisms for prediction improvement temperature processes, such as laser beam technologies. Surface tension is an elementary property that was measured in this study above the boiling steel using a laser-induced vapor channel substrate extraction diameter from in-situ X-ray observations. The measurement principle based on pressure balance inside keyhole, where recoil...
Laser hardening is a process that modifies not only hardness, but also residual stresses near the surface. However, limited information available on effect of multi-cycle phase transformation hardness and stresses, which could be possibility to achieve different material modifications. In this paper, effects multi-pass laser modifications quenched tempered as well ferrite/pearlite AISI 4140 steel have been investigated. The has carried out using continuous wave with rectangular beam shape...
Abstract Wire arc additive manufacturing (WAAM) of titanium parts shows promising potential for aerospace application due to its high deposition rates allowing a fast and economical production large components. The cost savings are high, especially expensive alloys like Ti-6Al-4V. However, oxygen affinity Ti-6Al-4V at elevated temperatures an excellent shielding gas coverage seems necessary prevent embrittlement the material during welding process. Regarding future development local set-ups...
Mechanical vibrations affect the nucleation and grain growth conditions during welding. In order to understand vibration-induced influences on formation in laser beam welding of aluminum thermal impacts simultaneously applied are analyzed this study. Therefore, deep penetration at vibration frequencies between 0.5 kHz 5 is investigated. Besides full penetration, partial experiments were carried out. The results show that absorption efficiencies not significantly affected by excitation....
Although laser brazing is well established, the energy-related efficiency of this joining method quite low. That because low absorptivity solid-state radiation, especially when copper base braze metals are used. Conventionally beam set close to vertical axis and filler wire delivered under a flat angle. Therefore, most utilized power reflected thus left unexploited. To address situation an alternative processing concept for brazing, where leading wire, has been investigated intending make...
Wetting steel surfaces with liquid aluminum without the use of flux can be enabled by presence a zinc-coating. The mechanisms behind this effect are not yet fully understood. Research results on single droplets falling commercial galvanized substrates revealed good wetting capability zinc coatings independently from coating type. final angle and length apparently linked to time where is liquefied during its contact overheated melt. This led assumption that interaction basically fluid dynamic...